February 2016

Prepared for:

Department of Veterans Affairs

Veterans Health Administration

Quality Enhancement Research Initiative

Health Services Research & Development Service

Washington, DC 20420 

Prepared by:

Evidence-based Synthesis Program (ESP) 

Minneapolis VA Health Care System

Minneapolis, MN 

Timothy J. Wilt, MD, MPH, Director

Department of Veterans Affairs

Health Services Research & Development Service Evidence-based Synthesis Program

Prevalence and 

Epidemiology of Combat 

Blast Injuries from the 

Military Cohort 2001-

2014 

Investigators:

Principal Investigator: 

Nancy Greer, PhD 

Co-investigators: 

Nina Sayer, PhD 

Mark Kramer, PhD

Research Associates:: 

Eva Koeller, BA

Tina Velasquez, MS
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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PREFACE

Quality Enhancement Research Initiative’s (QUERI) Evidence-based Synthesis Program (ESP) 

was established to provide timely and accurate syntheses of targeted healthcare topics of 

particular importance to Veterans Affairs (VA) clinicians, managers and policymakers as they 

work to improve the health and healthcare of Veterans. The ESP disseminates these reports 

throughout the VA, and some evidence syntheses inform the clinical guidelines of large 

professional organizations. 

QUERI provides funding for four ESP Centers and each Center has an active university 

affiliation. The ESP Centers generate evidence syntheses on important clinical practice topics, 

and these reports help: 

develop clinical policies informed by evidence;

guide the implementation of effective services to improve patient

outcomes and to support VA clinical practice guidelines and performance

measures; and

set the direction for future research to address gaps in clinical knowledge.

In 2009, the ESP Coordinating Center was created to expand the capacity of HSR&D Central 

Office and the four ESP sites by developing and maintaining program processes. In addition, the 

Center established a Steering Committee comprised of QUERI field-based investigators, VA 

Patient Care Services, Office of Quality and Performance, and Veterans Integrated Service 

Networks (VISN) Clinical Management Officers. The Steering Committee provides program 

oversight, guides strategic planning, coordinates dissemination activities, and develops 

collaborations with VA leadership to identify new ESP topics of importance to Veterans and the 

VA healthcare system.

Comments on this evidence report are welcome and can be sent to Nicole Floyd, ESP 

Coordinating Center Program Manager, at Nicole.Floyd@va.gov. 

Recommended citation: Greer N, Sayer N, Kramer M, Koeller E, Velasquez T, Wilt TJ. 

Prevalence and Epidemiology of Combat Blast Injuries from the Military Cohort 2001-2014. VA 

ESP Project #09-009; 2016. 

This report is based on research conducted by the Evidence-based Synthesis Program (ESP) Center 

located at the Minneapolis VA Health Care System, Minneapolis, MN, funded by the Department of 

Veterans Affairs, Veterans Health Administration, Office of Research and Development, Quality 

Enhancement Research Initiative. The findings and conclusions in this document are those of the 

author(s) who are responsible for its contents; the findings and conclusions do not necessarily represent 

the views of the Department of Veterans Affairs or the United States government. Therefore, no 

statement in this article should be construed as an official position of the Department of Veterans Affairs. 

No investigators have any affiliations or financial involvement (eg, employment, consultancies, honoraria, 

stock ownership or options, expert testimony, grants or patents received or pending, or royalties) that 

conflict with material presented in the report.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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TABLE OF CONTENTS

Executive Summary ...................................................................................................................... 1

Introduction ................................................................................................................................. 1

Methods ...................................................................................................................................... 2

Results ......................................................................................................................................... 3

Executive Summary Table 1. Incidence Data ............................................................................. 4

Executive Summary Table 2. Prevalence Data ........................................................................... 6

Executive Summary Table 3. Overview of Study Characteristics – Key Question 3 ................ 8

Executive Summary Table 4. Overview of Outcomes According to Blast versus Non-blast TBI 

– Key Question 3 ........................................................................................................................ 8

Discussion ................................................................................................................................... 9

Abbreviations Table .................................................................................................................. 12

Evidence Report .......................................................................................................................... 13

Introduction ................................................................................................................................. 13

Background ............................................................................................................................... 13

PICOTS ..................................................................................................................................... 14

Methods ........................................................................................................................................ 17

Topic Development ................................................................................................................... 17

Search Strategy ......................................................................................................................... 17

Study Selection ......................................................................................................................... 17

Data Abstraction ....................................................................................................................... 18

Risk of Bias Assessment ........................................................................................................... 18

Data Synthesis ........................................................................................................................... 18

Rating the Body of Evidence .................................................................................................... 18

Peer Review .............................................................................................................................. 18

Results .......................................................................................................................................... 19

Literature Flow ......................................................................................................................... 19

Key Question #1: What is the incidence of combat blast injuries associated 

with OEF, OIF, and OND as reported in the literature or in published reports 

from Department of Defense (DoD) and VA databases during the period 2001-2014? .......... 20

Key Question #1a: What is the incidence by blast characteristics (ie, primary, 

secondary, tertiary, quaternary, and quinary), injury site, and injury outcome? ...................... 20

Key Question #2: What is the prevalence of combat blast injuries associated 

with OEF, OIF, and OND as reported in the literature or in published reports 

from Department of Defense (DoD) and VA databases during the period 2001-2014? .......... 20
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Key Question #2a: What is the prevalence of blast injury by blast characteristics, 

injury site, and injury outcome? ............................................................................................... 20

Key Question #3: What are the short-term (up to 30 days), mid-term (30 days 

to one year) and long-term (greater than one year) injury outcomes (ie, pain, 

burns, limb loss, vision loss, hearing loss, vestibular dysfunction, PTSD, 

cognitive function, quality of life, functional status/employment, other) among 

US military personnel (2001-2014) who have sustained a blast-related TBI 

versus a non-blast TBI or a combined blast/non-blast TBI? .................................................... 24

Key Question #3a: What are the short-term (up to 30 days), mid-term (30 days 

to one year) and long-term (greater than one year) injury outcomes among US military 

personnel (2001-2014) who have sustained a blast-related TBI according to blast 

characteristics? .......................................................................................................................... 41

Summary and Discussion ........................................................................................................... 43

Summary of Evidence by Key Question ................................................................................... 43

Discussion ................................................................................................................................. 44

Limitations ................................................................................................................................ 45

Applicability of Findings to the VA Population ....................................................................... 46

Research Gaps/Future Research ............................................................................................... 47

Conclusions ............................................................................................................................... 47

References .................................................................................................................................... 49

Figures

Figure 1. Analytic Framework for Key Questions 1 and 2 ....................................................... 15

Figure 2. Analytic Framework for Key Question 3 .................................................................. 16

Figure 3. Literature Flow Chart ................................................................................................ 19

Tables

Table 1. Incidence Data ............................................................................................................ 21

Table 2. Prevalence Data .......................................................................................................... 23

Table 3. KQ3 Overview: Blast versus Non-blast TBI – Population & Study Characteristics . 25

Appendix A. Search Strategies .................................................................................................. 54

Appendix B. Peer Reviewer Comments and Responses .......................................................... 55

Appendix C. Evidence Tables .................................................................................................... 59

Table 1. Study Characteristics – Key Questions 1 and 2 .......................................................... 59

Table 2. Incidence and Prevalence Outcomes .......................................................................... 61
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Table 3. Study Characteristics – Key Question 3 ..................................................................... 64

Table 4a. Mortality Outcomes by Time Post-exposure – Key Question 3 ............................... 85

Table 4b. PTSD Outcomes by Time Post-exposure – Key Question 3 .................................... 85

Table 4c. Pain Outcomes by Time Post-exposure – Key Question 3 ....................................... 90

Table 4d. Burn Outcomes by Time Post-exposure – Key Question 3 ...................................... 91

Table 4e. Limb Loss Outcomes by Time Post-exposure – Key Question 3 ............................. 91

Table 4f. Vision Loss Outcomes by Time Post-exposure – Key Question 3 ........................... 92

Table 4g. Hearing Loss Outcomes by Time Post-exposure – Key Question 3 ........................ 94

Table 4h. Vestibular Dysfunction Outcomes by Time Post-exposure – Key Question 3 ........ 98

Table 4i. Cognitive Function Outcomes by Time Post-exposure – Key Question 3 .............. 101

Table 4j. Quality of Life Outcomes by Time Post-exposure – Key Question 3 ..................... 104

Table 4k. Functional Status/Employment Outcomes by Time Post-exposure – Key Question 3

 ................................................................................................................................................ 104

Table 4l. Other Outcomes by Time Post-exposure – Key Question 3 .................................... 106
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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EXECUTIVE SUMMARY

INTRODUCTION 

Combat blast injuries are typically categorized by the mechanism of injury. Primary blast injuries 

result from the over-pressurization wave and typically affect gas-filled body structures (eg, 

lungs, gastrointestinal tract, middle ear) resulting in injuries such as blast lung, tympanic 

membrane rupture, abdominal hemorrhage, and concussion. Secondary blast injuries result from 

flying debris propelled by the blast wind and may affect any body part. Blunt force or 

penetrating injuries are possible. Tertiary blast injuries occur when the body is accelerated by the 

blast wind or pressure gradients. Any body part may be affected and typical injuries include 

fracture and traumatic amputation, closed and open brain injuries, and crush injuries. Quaternary 

blast injuries are due to other products of the explosion (eg, heat, light) and exposure to toxins 

and gases. Any body part may be affected and injuries include burns, blindness, and respiratory 

problems from inhaled toxic gases. Quinary blast injuries include illnesses, injuries, and diseases 

resulting from post-explosion environmental contaminants (eg, bacteria, radiation). 

Despite recognition of greater use of improvised and other explosive devices in the Afghanistan 

and Iraq War counter-insurgency operations relative to prior conflicts, the scientific literature 

regarding the incidence and prevalence of explosive device-induced injuries is limited. 

Additionally, the consequences of experiencing a traumatic brain injury (TBI) related to blast 

exposure versus a TBI due to other mechanisms of injury may be different. Accurate assessment 

of the incidence and prevalence of blast- and non-blast-related injuries as well as their long-term 

outcomes is a critical first step in injury prevention, treatment, and health system resource 

management. The purpose of this report is to systematically review the literature on 1) incidence 

and prevalence of combat blast injuries sustained during Operation Enduring Freedom (OEF), 

Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) 2001 through 2014 and 2) the 

outcomes (eg, pain, vision loss, cognitive function, quality of life) following blast versus nonblast TBI.

We developed the following Key Questions with input from stakeholders and Technical Expert 

Panel (TEP) members:

Key Question #1: What is the incidence of combat blast injuries associated with OEF, OIF, and 

OND as reported in the literature or in published reports from Department of Defense (DoD) and 

VA databases during the period 2001-2014? 

Key Question #1a: What is the incidence by blast characteristics (ie, primary, secondary, 

tertiary, quaternary, and quinary), injury site, and injury outcome? 

Key Question #2: What is the prevalence of combat blast injuries associated with OEF, OIF, 

and OND as reported in the literature or in published reports from Department of Defense (DoD) 

and VA databases during the period 2001-2014? 

Key Question #2a: What is the prevalence of blast injury by blast characteristics, injury 

site, and injury outcome? 
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Key Question #3: What are the short-term (up to 30 days), mid-term (30 days to one year) and 

long-term (greater than one year) injury outcomes (ie, pain, burns, limb loss, vision loss, hearing 

loss, vestibular dysfunction, mental health/PTSD, cognitive function, quality of life, functional 

status/employment, other-organ system-specific) among US military personnel (2001-2014) who 

have sustained a blast-related TBI versus a non-blast TBI or a combined blast/non-blast TBI?

Key Question #3a: What are the short-term (up to 30 days), mid-term (30 days to one year) 

and long-term (greater than one year) injury outcomes among US military personnel (2001-

2014) who have sustained a blast-related TBI according to blast characteristics?

METHODS 

Data Sources and Searches 

We searched MEDLINE (Ovid) for articles published in English from 2000 through April 2015 

using separate search strategies for Key Questions 1 and 2 and Key Question 3. Our searches 

were designed to identify studies of combat injuries in US military personnel during OEF, OIF, 

and OND. The full search strategies are presented in Appendix A. We obtained additional 

articles by hand-searching the table of contents of Journal of Trauma-Injury Infection & Critical 

Care and reference lists of systematic reviews and other reports, and from references suggested 

by stakeholders, TEP members, and peer reviewers. 

Study Selection 

Abstracts from the MEDLINE searches were reviewed in duplicate by investigators and research 

associates and abstracts from the table of contents search were reviewed by a single investigator. 

We identified for full-text review studies of any design potentially relevant to the key questions. 

Two investigators or research associates independently reviewed full-text articles excluding the 

following: 

Studies not including US military personnel from OEF, OIF, or OND (2001-2014); 

Studies not involving combat injuries; 

Modeling studies (eg, mechanical/engineering models, animal studies);

Studies not relevant to the key questions; 

Studies of treatment outcomes;

Imaging studies or studies reporting changes in tissue (eg, white matter);

Case reports; 

Studies for Key Questions 1 and 2 where the denominator was not the number deployed 

during the study period (ie, reports of injuries at a medical facility were excluded); and

Studies for Key Question 3 that did not report outcomes of interest for blast-related TBI 

and non-blast TBI groups (ie, studies only reporting on blast-related TBI were 

excluded).

Data Abstraction and Risk of Bias Assessment 

Study characteristics and outcomes were extracted onto evidence tables by one investigator or 

research associate and verified by another. We did not assess the risk of bias of the included 

studies although risk of bias for each study was likely moderate or high due to the study design 

used, selective population studied, and failure to control for potential confounding factors. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Data Synthesis and Analysis 

We created summary tables for incidence and prevalence data (Key Questions 1 and 2). We 

organized evidence tables for Key Question 3 by outcome and time since exposure (< 30 days, 

30 days to 1 year, > 1 year, or not specified). Pooled analyses were not possible due to 

heterogeneity of the study populations and outcome measures. 

We did not formally rate the overall strength of evidence for outcomes. The typical approach to 

assessing strength of evidence considers consistency, precision, directness, and risk of bias of the 

included studies. However, because included studies were observational and there was limited 

reporting of outcomes of interest (ie, most outcomes reported in only a few studies and often 

using different measures), it is unlikely that strength of evidence would be anything above low. 

Many outcomes had insufficient evidence.

RESULTS

Results of Literature Search 

Our literature searches yielded 1,146 abstracts. We identified 324 articles for full-text review and 

excluded 290. We identified an additional 8 articles by hand-searching, resulting in a total of 42 

included articles (6 for Key Questions 1 and 2, 36 from 34 studies for Key Question 3). 

Summary of Results for Key Questions 

Key Questions 1 and 2

We identified 6 studies meeting inclusion criteria for Key Questions 1 or 2 (incidence and 

prevalence of combat blast injuries). These studies included data from 2001 to 2011; 5 used the 

Joint Theater Trauma Registry (JTTR) and one used Department of Defense tabular reports. 

Three of the JTTR studies were based on the same cohort of deployed service members 

(described by Belmont et al, 2012) with one reporting overall casualties, one reporting 

musculoskeletal casualties, and one reporting spinal injuries. The JTTR (now the Department of 

Defense Trauma Registry [DoDTR]) was established in 2004 and contains information on all 

casualties (individuals lost to the theater of operations due to illness or injury) treated at US 

military medical facilities in and outside the combat zone. All but one study, which focused on 

the troop surge in Iraq, included casualties from both Iraq and Afghanistan. The mean ages of 

service members in the study cohorts ranged from 26 to 30 years, and 92% to 99% were male (k 

= 5 reporting). In the 4 studies that reported branch of service and rank, 78% to 100% were from 

the Army and the large majority (up to 93%) were from enlisted ranks. None of the studies 

provided information on deployment details including assigned or actual duties. Additional 

details are presented in Appendix C, Tables 1 and 2. 

Key Question 1. Incidence

The National Institute of Mental Health defines incidence as the number of new cases of a 

condition, symptom, death, or injury that develop during a specific time period. We included 

registry studies that reported incidence of combat blast injuries for the deployed population 

(Executive Summary Table 1). 
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Belmont et al (2012) reported incidence of explosion (ie, improvised explosive device, mortar, 

and rocket-propelled grenade) injuries for the years 2005 to 2009. Soldiers killed in action or 

sustaining non-battle injuries were not included in the analysis. The number of service members 

deployed and years of service were obtained through the Defense Manpower Data Center. The 

incidence was 4.5 blast injuries per 1,000 deployed in 2005, 3.5 per 1,000 in 2006, 4.0 per 1,000 

in 2007, 1.7 per 1,000 in 2008, and 1.7 per 1,000 in 2009. The slight increase in 2007 

corresponded to the troop surge. 

A second report detailed all combat explosion injuries in a US Army Brigade Combat Team (n = 

4,122) deployed during the 2007 troop surge in Iraq. The cohort was followed for 6 months 

following the 15-month deployment. The incidence of explosion injuries was 83 per 1,000 

deployed soldiers. 

Executive Summary Table 1. Incidence Data

Outcome 2005 2006 2007 2008 2009 2010

Explosion injuries (any) per 

1,000 deployed (Belmont 

2010)

 83a 

Explosion injuries (any) per 

1,000 deployed (Belmont 

2012)

4.5 3.5 4.0 1.7 1.7 

Explosion-related 

musculoskeletal injuries

per 1,000 deployedb

(Belmont 2013)

3.5 2.7 3.1 1.3 1.3 

Explosion-related spinal 

injuries per 1,000 deployedb 

(Schoenfeld 2013)

0.4 0.4 0.4 0.2 0.3 

Blast-related thoracolumbar 

burst fractures per 10,000 

soldier years (Freedman 

2014)

 0.45c 0.60c 2.08c

a All explosion injuries for a US Army Brigade Combat Team (n = 4,122) deployed during the 2007 troop surge b Additional analysis of cohort described by in Belmont 2012

c Data from August of preceding year to August of specified year

Key Question 1a 

No study reported incidence by blast characteristics (ie, primary, secondary, etc) or injury 

outcomes (eg, pain, amputations, vision loss, cognitive function, functional status, quality of 

life). Three reported incidence by injury site (ie, body location or system injured) (Executive 

Summary Table 1). 

Two of the studies provided information about specific injury types for the service members 

deployed to Afghanistan and Iraq and included in the cohort described by Belmont et al 2012. 

One study identified explosion-related musculoskeletal injuries (upper and lower extremity, 

spine, and pelvis wounds including fractures, soft tissue injuries, joint dislocations, neurologic 

injuries, and traumatic amputations) during a 5-year period. The incidence values (per 1,000 

deployed soldiers) were 3.5 in 2005, 2.7 in 2006, 3.1 in 2007, 1.3 in 2008, and 1.3 in 2009. The 

other study reported on explosion-related spinal injuries finding 0.4 per 1,000 deployed soldiers 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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in 2005, 2006, and 2007; 0.2 per 1,000 soldiers in 2008; and 0.3 per 1,000 soldiers in 2009. The 

injuries included fractures, dislocations, disk displacements, nerve root injuries, and spinal cord 

injuries.

Another study looked specifically at combat thoracolumbar burst fractures, a pattern of injury 

that occurs as a result of vertical forces imparted by an explosion beneath an armored vehicle. 

The analysis included service members injured in Afghanistan and Iraq. The incidence of 

thoracolumbar burst fractures increased from 0.45 per 10,000 soldier-years in the one-year 

period August 2007-2008, to 0.60 per 10,000 soldier-years in August 2008-2009, and 2.08 per 

10,000 soldier-years in August 2009-2010. The increase in 2009-2010 was largely among 

soldiers serving in Afghanistan and authors attributed this to increased use of powerful 

improvised explosive devices against newer, up-armored vehicles. Authors speculated that with 

the newer military vehicles, explosives that might have caused deaths in the past were now 

associated with non-fatal burst fracture injuries. 

Key Question 2. Prevalence

The National Institute of Mental Health has defined prevalence as the proportion of a population 

who have (or had) a specific condition in a given time period regardless of when they first 

acquired the condition. For this review, we report cumulative data as prevalence (Executive 

Summary Table 2). 

Explosion-related injuries over a 5-year period (2005-2009) were reported for the Belmont et al

cohort. Among 1,992,232 soldiers deployed to Afghanistan or Iraq during that time period, there 

were 5,862 explosion injuries, or 0.29% of deployed soldiers experienced an explosion-related 

injury. Explosion injuries accounted for 74% of injuries. 

Key Question 2a 

No studies reported prevalence by blast characteristic or injury outcome.

Four studies reported specific injury sites (Executive Summary Table 2). Two studies were 

additional analyses of the Belmont et al cohort. The study of musculoskeletal injuries reported 

4,563 soldiers with explosion-related injuries (0.23% of deployed soldiers). Of all 

musculoskeletal injuries, 82% were explosion-related. Another analysis reported there were 650 

soldiers with explosion-related spinal injuries (0.03% of deployed soldiers). Of all spinal 

injuries, 75% were explosion-related. Among the 650 with explosion-related spinal injuries, 31% 

(n = 204) had injuries to more than one spinal region. Associated head and neck injuries were 

noted in 57% (n = 132) of soldiers with an explosion-related cervical spine injury. 

The study of thoracolumbar burst fractures reported that over the period 2007-2010, the rate of 

blast-related fractures was 2.02 per 10,000 soldier-years. A Congressional Budget Office 

Working Paper reported major amputations (loss of a limb proximal to the wrist or ankle). The 

prevalence was 38 per 100,000 troop-years in OEF and OND and 88 per 100,000 troop-years in 

OEF.
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Executive Summary Table 2. Prevalence Data

Outcome 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Explosionrelated 

injuries 

(any)

(Belmont 

2012)

 

74% of injuries

0.29% of 1,992,232 deployed

(30.5 per 10,000 deployed)

 

Blast-related 

thoracolumbar burst 

fractures

(Freedman 

2014)

2.02 per 10,000 soldier-years

Explosionrelated 

musculoskeletal 

injuries

(Belmont 

2013)

82% of musculoskeletal wounds

(14,158 wounds)

0.23% of 1,992,232 deployed

(22.9 per 10,000 deployed)

Explosionrelated 

spinal 

injuries

(Schoenfeld 

2013)

75% of spinal casualties

0.03% of 1,992,236 deployed

(3.3 per 10,000)

Improvised 

explosive 

device major 

amputations

(Goldberg

2014)

Iraq (OEF, OND): 38.3/100,000 troop-years

Afghanistan (OEF): 87.8/100,000 troop-years

Key Question 3 

We included 34 studies (in 36 papers). Executive Summary Table 3 provides an overview of the 

studies. The majority of reports were clinical cohort studies with patient injury outcomes (eg, 

post-traumatic stress disorder [PTSD], pain, limb loss, vision impairment, cognitive function 

loss) assessed at a medical facility in the US. Many studies did not report the time from blast 

exposure to assessment. Of those that did, most assessments took place 30 days to one year postexposure. Eighteen of the 34 studies included only patients with mild TBI. 

Injury outcomes are summarized in Executive Summary Table 4. In studies of injury outcomes 

among military personnel sustaining a blast or non-blast TBI, blast and non-blast groups had 

similar rates of mortality, pain, vision loss, vestibular dysfunction, functional ability, depression, 

sleep disorders, alcohol misuse, and post-concussive symptoms. Results were consistent across 

studies despite the fact that the studies varied in sample size, location where assessment took 

place, time from exposure to assessment (< 30 days, 30 days to one year, or > one year), and 

level of TBI severity.
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Findings were less consistent for PTSD, hearing loss, cognitive function loss, and headache, with 

some studies finding increased levels in the blast-related TBI groups and some finding blast and 

non-blast groups to be similar. Burn injuries, limb loss, and quality of life were infrequently 

reported (3, 2, and one study, respectively).

We found little data on outcomes according to blast characteristics. One study failed to find a 

difference in hearing outcomes by primary versus secondary blast injuries. Three studies that 

defined blast injury as due to primary blast force reported few differences between their blast 

injury group and non-blast injury comparator groups.
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Executive Summary Table 3. Overview of Study Characteristics – Key Question 3

Number of Studies

Data Source

Sample 

Size

Characteristics

Registry/

Database

Clinical Cohort

Location of Assessmenta Time Since Exposureb TBI Severityc 

Combat 

Zone

After 

Deployment

DoD, VA 

or Other 

Medical 

Facility

< 30 

days

30 days to 

1 year > 1 year Any or 

Unclear

Mild

Moderate/

Severe

Mixed 

(results not 

reported 

separately)

34 6 28 18 to 

12,521 3 2 26 3 10 5 14 18 1 12

a 2 additional studies: 1 completed in combat zone and at end of deployment; 1 unclear b 2 additional studies: both with outcomes at <30 days and 30 days to 1 year post exposure c 3 additional studies; 2 included mild and moderate/severe TBI with results reported separately; 1 included all severity levels reporting some results separately

Executive Summary Table 4. Overview of Outcomes According to Blast versus Non-blast TBI – Key Question 3

Number of 

Studies

Data Source Outcomes Reporteda Mortality PTSD Pain Burn Limb Loss Vision Impairment Hearing Impairment Vestibular Dysfunction Cognitive 

Function 

Loss

Quality of 

Life

Functional 

Status/

Employment

Other

Registry/

Database

Clinical 

Cohort

34 6 28 ↔2 

-7 

↔8

1 MIXED

↔3

-1 

↔1

?1

-1 

↔1

-1 

↔5

 ̄1 

1 MIXED

-4 

↔3

2 MIXED

-1 

↔4

1 MIXED

-2 

↔5

3 MIXED

↔1 ↔4

 ̄1

Depression: ↔7

Sleep: -1, ↔3, 1 MIXED

Headache: ↔2, 2 MIXED

Alcohol misuse: ↔3

Post-concussive 

symptoms: -1, ↔4 

Injury severity: ↔1, ?1

TBI severity: -1, ↔2, ?1 a Number is number of studies reporting that outcome; symbol provides direction of statistically significant outcomes

- Higher prevalence or more severe in blast TBI group;  ̄ Higher prevalence or more severe in non-blast TBI group; ↔ Blast and non-blast groups similar; ? P value not reported 

MIXED Multiple tests with mixed results
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DISCUSSION

Key Findings

Key Questions 1 and 1a - Incidence

The published literature provides limited information about the true incidence and 

prevalence of blast-related injuries experienced by US military personnel. Findings are 

likely influenced by assessment and reporting methods. 

The reported explosion injury incidence ranged from 4.5/1,000 deployed in 2005 to 

1.7/1,000 deployed in 2009. 

During the Iraq troop surge (2007) explosion injury incidence was particularly high 

(83/1,000 deployed in a US Army Brigade Combat Team).

Musculoskeletal explosion injury incidence (fractures, amputations, neurological injuries, 

joint dislocations, and soft tissue injuries) ranged from 3.5/1,000 deployed in 2005 to 

1.3/1,000 deployed in 2009.

Spinal injury incidence (fractures, dislocations, nerve root injuries, spinal cord injuries) 

ranged from 0.18/1,000 deployed in 2008 to 0.40/1,000 deployed in 2005.

Thoracolumbar burst fracture incidence was low (0.45 to 2.1 per 10,000 soldier years

between 2008 and 2010) but higher in Afghanistan than Iraq and increased over the study 

period.

No study reported incidence by blast characteristics.

Key Question 2 and 2a - Prevalence

Nearly three-quarters of all combat injuries over the period from 2005 to 2009 (31 per 

10,000 deployed) were due to explosions.

A high proportion of musculoskeletal injuries (82%; 23 per 10,000 deployed) and spinal 

injuries (75%; 3 per 10,000 deployed) between 2005 and 2009 were due to explosions. Of 

the musculoskeletal injuries, 80% of axial skeletal and extremity fractures, 94% of 

amputations, and 85% of soft tissue injuries were explosion-related. Another study 

reported explosion-related amputations in 4 per 10,000 troop-years (Iraq) and 9 per 

10,000 troop-years (Afghanistan) over the period from 2001 to 2011.

No study reported prevalence by blast characteristics.

Key Question 3

The published literature provides limited information on outcomes associated with blast 

versus non-blast TBI experienced by US military personnel. Definitions of blast/nonblast injury, assessment of outcomes, and reporting methods vary and often are based on 

small selected groups. 
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Blast and non-blast TBI groups had similar rates of pain, vision loss, vestibular 

dysfunction, functional ability, depression, sleep disorders, alcohol misuse, and postconcussive symptoms. 

Comparative outcomes in individuals with blast versus non-blast TBI were inconsistent 

across studies with regard to PTSD diagnosis or symptom severity, hearing loss, 

cognitive function, and headache in blast and non-blast TBI groups. 

Mortality, burn injuries, limb loss, and quality of life were infrequently reported in 

studies comparing blast versus non-blast TBI. 

Results were consistent across studies that varied by location of assessment (combat 

zone, medical facility), time from exposure to assessment (< 30 days, 30 days to one 

year, or > one year), and level of TBI severity, although the most studies were small, 

clinical cohort studies, with mTBI patients evaluated at a Department of Defense or 

Veterans Affairs medical facility.

There is little data on outcomes among those with TBI according to blast characteristics.

Applicability

The findings of this review are highly applicable to military personnel and organizations that 

provide direct acute or chronic health care services including rehabilitation as well as 

employment to those either currently serving or of recent Veteran status. Additionally, an 

understanding of the incidence, prevalence, outcomes, and causal factors of blast and non-blast 

injuries may be used to help reduce these injuries in future combat operations. 

However, many studies reported findings from individuals presenting to medical facilities and 

undergoing treatment for a specific combat injury. Patient and injury characteristics and 

subsequent health outcomes from these selected patients may differ in unknown ways from the 

broader group of individuals who had combat injuries. We also have little information on very 

long-term effects (eg, cognitive function decline over decades).

The Analysis of VA Health Care Utilization among Operation Enduring Freedom (OEF), 

Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) Veterans (released June 2015) 

reports that 1,906,754 OEF/OIF/OND Veterans have become eligible for VA health care since 

fiscal year 2002 (beginning October 1, 2001) and approximately 2.7 million troops (as of 

December 31, 2014) have served or are serving in the 2 theaters of operation since the beginning 

of the conflicts in Iraq and Afghanistan. OEF/OIF/OND Veterans who present for care at a VA 

facility undergo a screen for TBI which includes questions about exposure to physical trauma

such as explosions. Veterans who screen positive for TBI undergo a comprehensive evaluation. 

Research Gaps/Future Research

Accurately recording in a standardized fashion every injury to every individual who experiences 

a blast (including type of blast [eg, primary, secondary, etc], distance from the blast, etc) and 

then following those individuals to assess long-term outcomes would be ideal but not realistic. 

However, for those who have been determined to have received blast-related injuries additional 

information on the circumstances surrounding the injury should include: type of blast, distance 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

11

from the blast, history of blast exposure, injury severity, assigned and actual duties, and military 

member’s physical and psychosocial characteristics. Additional information gathered would be 

useful to evaluate methods to reduce combat-related blast injuries. Comparisons versus deployed 

controls may facilitate our understanding of the mechanisms and severity of blast-related injuries 

and the long-term health and social consequences of those injuries. This includes not only the 

treatments and health outcomes specific to the blast injury but also the long-term psychosocial, 

employment, and economic impact of blast injuries and the role and capacity needs for health 

care systems and the work force as these individuals reintegrate into the civilian society. Existing 

databases may already contain some of this information and future analyses should incorporate 

blast data where possible.

Conclusions

The published literature provides limited information about the true incidence and 

prevalence of blast-related injuries experienced by US military personnel and the 

outcomes associated with blast versus non-blast TBI. We found no reports of incidence 

and prevalence of blast injuries associated with different combat roles.

Few studies of incidence of blast-related injuries or outcomes associated with blast versus 

non-blast TBI report important characteristics of a blast injury: type of blast, how far the 

individual was from the blast, whether they experienced a blast wave, whether there was 

loss of consciousness or altered consciousness, whether there was amnesia (and length of 

time), and whether there was additional trauma.

Only 6 studies, 3 of which were derived from the same data set, provide information 

about the incidence and prevalence of blast-related injuries in the deployed population at 

risk.

Pain, vision loss, vestibular dysfunction, functional status, depression, sleep disturbance, 

alcohol misuse, and post-concussive symptoms were similar in groups of patients with 

blast and non-blast TBI. Findings were less consistent for PTSD, hearing loss, cognitive 

function, and headache. Few studies reported mortality, burn outcomes, limb loss, or 

quality of life. 

Reporting studies were often small and involved highly selected patients and thus may 

not be fully representative of all individuals with blast or non-blast TBI. There are few

data on very long-term outcomes that may be particularly relevant to assessment of 

cognitive function and quality of life. 

Blast and blast injuries (including TBI) are often defined differently. Therefore, the 

incidence, prevalence, and patient outcomes may vary across studies in part due to 

differences in how blast injury is categorized. 

To more adequately address questions about consequences of blast exposure, future 

research efforts should focus on comprehensive and consistent documentation at the time 

of and following blast exposure and more complete analyses of databases that may

already have captured blast exposure information.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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ABBREVIATIONS TABLE

DoD Department of Defense

DOW Died of wounds

KIA Killed in action

OEF Operation Enduring Freedom

OIF Operation Iraqi Freedom

OND Operation New Dawn

PTSD Post-traumatic Stress Disorder

RTD Returned to duty

TBI (mTBI) Traumatic brain injury (mild traumatic brain injury)

VA Department of Veterans Affairs

VAMC Veterans Affairs Medical Center

WIA Wounded in action
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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EVIDENCE REPORT

INTRODUCTION 

BACKGROUND 

Combat blast injuries are typically categorized by the mechanism of injury.1-5 Primary blast 

injuries result from the over-pressurization wave and typically affect gas-filled body structures 

(eg, lungs, gastrointestinal tract, middle ear) resulting in injuries such as blast lung, tympanic 

membrane rupture, abdominal hemorrhage, and concussion. Secondary blast injuries result from 

flying debris propelled by the blast wind and may affect any body part. Blunt force or 

penetrating injuries are possible. Tertiary blast injuries occur when the body is accelerated by the 

blast wind or pressure gradients. Any body part may be affected and typical injuries include 

fracture and traumatic amputation, closed and open brain injuries, and crush injuries. Quaternary 

blast injuries are due to other products of the explosion (eg, heat, light) and exposure to toxins 

and gases. Any body part may be affected and injuries include burns, blindness, and respiratory 

problems from inhaled toxic gases. Quinary blast injuries include illnesses, injuries, and diseases 

resulting from post-explosion environmental contaminants (eg, bacteria, radiation). Factors such 

as type of explosive, distance from the explosion, and body orientation relative to the explosion 

influence the impact of the explosion on the body.4

Despite recognition of greater use of improvised and other explosive devices in the Afghanistan 

and Iraq War counter-insurgency operations relative to prior conflicts, the scientific literature 

regarding the incidence and prevalence of explosive device induced injuries is limited. 

Additionally, the consequences of experiencing a traumatic brain injury (TBI) related to blast 

exposure versus a TBI due to other mechanisms of injury (eg, motor vehicle accident, fall) may 

be different.

3,4 Accurate assessment of the incidence and prevalence of blast and non-blastrelated injuries as well as their long-term outcomes is a critical first step in injury prevention, 

treatment, and health system resource management. The purpose of this report is to 

systematically review the literature on 1) incidence and prevalence of combat blast injuries 

sustained during Operation Enduring Freedom (OEF), Operation Iraqi Freedom (OIF), and 

Operation New Dawn (OND) 2001 through 2014 and 2) the outcomes (eg, pain, vision loss, 

cognitive function, quality of life) following blast versus non-blast TBI.

We developed the following key questions for this review with input from stakeholders and 

Technical Expert Panel (TEP) members:

Key Question #1: What is the incidence of combat blast injuries associated with OEF, OIF, and 

OND as reported in the literature or in published reports from Department of Defense (DoD) and 

VA databases during the period 2001-2014? 

Key Question #1a: What is the incidence by blast characteristics (ie, primary, secondary, 

tertiary, quaternary, and quinary),1,2

 injury site, and injury outcome? 

Key Question #2: What is the prevalence of combat blast injuries associated with OEF, OIF, 

and OND as reported in the literature or in published reports from Department of Defense (DoD) 

and VA databases during the period 2001-2014? 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Key Question #2a: What is the prevalence of blast injury by blast characteristics, injury 

site, and injury outcome? 

Key Question #3: What are the short-term (up to 30 days), mid-term (30 days to one year) and 

long-term (greater than one year) injury outcomes (ie, pain, burns, limb loss, vision loss, hearing 

loss, vestibular dysfunction, PTSD, cognitive function, quality of life, functional 

status/employment, other) among US military personnel (2001-2014) who have sustained a blastrelated TBI versus a non-blast TBI or a combined blast/non-blast TBI?

Key Question #3a: What are the short-term (up to 30 days), mid-term (30 days to one year) 

and long-term (greater than one year) injury outcomes among US military personnel (2001-

2014) who have sustained a blast-related TBI according to blast characteristics?

PICOTS

The Population, Intervention, Comparator, Outcomes, Timing, and Setting (PICOTS) for the 

review are outlined below and displayed on analytic frameworks for Key Questions (KQ) 1 and 

2 (Figure 1) and KQ 3 (Figure 2) 

Population: Military cohort 2001-2014 

Intervention: Combat blast injury (KQ1, KQ2) or blast-related TBI (KQ3)

Comparator: Non-blast or combined blast/non-blast TBI (KQ3) 

Outcomes: Incidence and prevalence of combat blast injuries by blast characteristics, injury site, 

and injury outcome (KQ1, KQ2); injury outcomes for blast versus non-blast or combined TBI 

and injury outcomes by blast characteristics for blast-related TBI (KQ3)

Timing: Any duration from time of exposure (duration to be reported if available); injury 

outcomes categorized as short-term (up to 30 days after blast), mid-term (30 days to one year), 

and long-term (greater than one year)

Setting: Any active service setting (ie, training, deployment). 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Figure 1. Analytic Framework for Key Questions 1 and 2
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Figure 2. Analytic Framework for Key Question 3
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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METHODS 

TOPIC DEVELOPMENT

This topic was nominated by Ralph DePalma, MD, Special Operations Office, Office of 

Research and Development. Additional stakeholders included: David Cifu, MD, Chair, VHA 

TBI Advisory Committee; Stuart Hoffman, PhD, Scientific Program Manager for Brain Injury, 

Rehabilitation Research and Development Service; and Col. Todd Rasmussen, MD, Director, 

Combat Casualty Care Research Program, US Army Medical Research and Materiel Command. 

Information on the incidence and prevalence of combat blast injuries and the outcomes of blastrelated and non-blast TBI may be used to allocate research funding appropriately to improve care 

for Veterans with blast injuries and/or TBIs. 

SEARCH STRATEGY 

We searched MEDLINE (Ovid) for articles published in English from 2000 through April 2015 

using separate search strategies for Key Questions 1 and 2 and Key Question 3. Our searches 

were designed to identify studies of combat injuries in US military personnel during OEF, OIF, 

and OND. The searches included the MeSH terms Brain Injuries; Wounds, Nonpenetrating; 

Wounds, Penetrating; Afghan Campaign 2001-; Iraq War, 2003-2011; and Military Personnel. 

The full search strategies are presented in Appendix A. We obtained additional articles by handsearching the table of contents of Journal of Trauma-Injury Infection & Critical Care and 

reference lists of systematic reviews and other reports, and from references suggested by the 

topic stakeholders and TEP members. 

STUDY SELECTION

Abstracts from the MEDLINE searches were reviewed in duplicate by investigators and research 

associates and abstracts from the table of contents search were reviewed by a single investigator. 

We identified for full-text review studies of any design potentially relevant to the key questions. 

Two investigators or research associates independently reviewed full-text articles excluding the 

following: 

Studies not including US military personnel from OEF, OIF, or OND (2000-2014); 

Studies not involving combat injuries; 

Modeling studies (eg, mechanical/engineering models, animal studies); 

Studies not relevant to the key questions; 

Studies of treatment outcomes; 

Imaging studies or studies reporting changes in tissue (eg, white matter); 

Case reports; 

Studies for Key Questions 1 and 2 where the denominator was not the number deployed 

during the study period (ie, reports of injuries at a medical facility were excluded); and

Studies for Key Question 3 that did not report outcomes of interest for blast-related TBI 

and non-blast TBI groups (ie, studies only reporting on blast-related TBI were 

excluded).
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DATA ABSTRACTION

For Key Questions 1 and 2, study characteristics (data source, inclusion/exclusion criteria, cohort 

characteristics) and outcomes (blast injury incidence, blast injury prevalence) were extracted into 

evidence tables by one investigator or research associate and verified by another. For Key 

Question 3, study characteristics (data source, inclusion exclusion criteria, cohort characteristics, 

outcome measures used) and outcomes (mortality, pain, burns, limb loss, vision loss, hearing 

loss, vestibular dysfunction, PTSD, cognitive function, quality of life, functional 

status/employment, other) for blast-related TBI and non-blast TBI patients were extracted into 

evidence tables by one investigator or research associate and verified by another. 

RISK OF BIAS ASSESSMENT 

We did not assess the risk of bias of the included studies, although risk of bias for each study was 

likely moderate or high due to the study design used, selective population studied, and failure to 

control for potential confounding factors. 

DATA SYNTHESIS

We created summary tables with incidence and prevalence results (Key Questions 1 and 2). We 

organized evidence tables for Key Question 3 by outcome and time since exposure (<30 days, 30 

days to 1 year, >1 year, or not specified). Pooled analyses were not possible due to heterogeneity 

of the study populations and outcome measures. 

RATING THE BODY OF EVIDENCE

We did not formally rate the overall strength of evidence for outcomes. The typical approach to 

assessing strength of evidence considers consistency, precision, directness, and risk of bias of the 

included studies. However, because included studies were observational and there was limited 

reporting of outcomes of interest (ie, most outcomes reported in only a few studies and often 

using different measures), it is unlikely that strength of evidence would be anything above low. 

Many outcomes had insufficient evidence.

PEER REVIEW

A draft version of this report was reviewed by content experts as well as clinical leadership. 

Reviewer’s comments and our responses are presented in Appendix B and the report was 

modified as needed.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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RESULTS 

LITERATURE FLOW 

Our literature searches yielded 1,146 abstracts (Figure 3). We identified 324 articles for full-text 

review and excluded 290. We identified an additional 8 articles by hand-searching resulting in a 

total of 42 included articles (6 for Key Questions 1 and 2, 36 from 34 studies for Key Question 

3).

Figure 3. Literature Flow Chart

Full text review: 324 Articles, dual review

Reference Lists of 

Included Studies and 

Review Articles; Peer 

Reviewer Suggestions:

8 Articles

Included

KQ 1 and 2: 6 Studies

KQ 3: 34 Studies (36 

Articles)

MEDLINE Search and J Trauma-Injury Infection & Critical Care 

Table of Contents Search through April 2015

1,146 Abstract

Excluded: 290 articles

Not US Military: 17 

Not 2001-2014: 6

Not Combat Injuries: 20

Modeling or Imaging Study: 35

No Outcomes of Interest: 38

Incorrect Denominator (KQ1, 2): 90

Not Blast vs Non-blast TBI (KQ3): 75

Case Report: 9

Excluded: 822 Abstracts
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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KEY QUESTION #1: What is the incidence of combat blast injuries 

associated with OEF, OIF, and OND as reported in the literature or in 

published reports from Department of Defense (DoD) and VA 

databases during the period 2001-2014?

KEY QUESTION #1A: What is the incidence by blast characteristics 

(ie, primary, secondary, tertiary, quaternary, and quinary), injury 

site, and injury outcome?

KEY QUESTION #2: What is the prevalence of combat blast injuries 

associated with OEF, OIF, and OND as reported in the literature or in 

published reports from Department of Defense (DoD) and VA 

databases during the period 2001-2014?

KEY QUESTION #2A: What is the prevalence of blast injury by blast 

characteristics, injury site, and injury outcome?

Overview of Studies

We identified 6 studies meeting inclusion criteria for Key Questions 1 or 2. These studies 

included data from 2001 to 2011; 5 used the Joint Theater Trauma Registry (JTTR)6-10 and one 

used Department of Defense tabular reports.11 Three of the JTTR studies were based on the same 

cohort of deployed service members with one reporting overall casualties,8 one reporting 

musculoskeletal casualties,7 and one reporting spinal injuries.9 The JTTR (now the Department 

of Defense Trauma Registry [DoDTR]) was established in 2004 and contains information on all 

casualties (individuals lost to the theater of operations due to illness or injury) treated at US 

military medical facilities in and outside the combat zone. All but one study, which focused on 

the troop surge in Iraq,6 included casualties from both Iraq and Afghanistan. The mean ages of 

service members in the study cohorts ranged from 26 to 30 years and 92% to 99% were male (k

= 5 reporting). In the 4 studies that reported branch of service and rank, 78% to 100% were from 

the Army and the large majority (up to 93%) were from enlisted ranks. None of the studies 

provided information on deployment details including assigned or actual duties. Additional 

details are presented in Appendix C, Tables 1 and 2.

Key Question #1. Incidence

The National Institute of Mental Health has defined incidence as the number of new cases of a 

condition, symptom, death, or injury that develop during a specific time period.12 We included 

registry studies that reported incidence of combat blast injuries for the deployed population

(Table 1). 

One study reported incidence of explosion (ie, improvised explosive device, mortar, rocket 

propelled grenade) injuries for the years 2005 to 2009.8 Soldiers killed in action or sustaining 

non-battle injuries were not included in the analysis. The number of service members deployed 

and years of service were obtained through the Defense Manpower Data Center. The incidence 

was 4.5 explosion injuries per 1,000 deployed in 2005, 3.5 per 1,000 in 2006, 4.0 per 1,000 in 

2007, 1.7 per 1,000 in 2008, and 1.7 per 1,000 in 2009. The slight increase in 2007 corresponded 

to the troop surge. Findings were also reported by country (Afghanistan versus Iraq).

8 In 2005 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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explosion injury incidence was higher in Iraq but beginning in 2008, the incidence was higher 

among soldiers deployed in Afghanistan. 

A second report detailed all combat explosion injuries in a US Army Brigade Combat Team (n = 

4,122) deployed during the 2007 troop surge in Iraq.

6

 The cohort was followed for 6 months 

following the 15-month deployment. The incidence of explosion injuries was 83 per 1,000 

deployed soldiers. 

Table 1. Incidence Data

Outcome 2005 2006 2007 2008 2009 2010

Explosion injuries (any) per 

1,000 deployed6 83a

 

Explosion injuries (any) per 

1,000 deployed8 4.5 3.5 4.0 1.7 1.7 

Explosion-related 

musculoskeletal injuries per 

1,000 deployed7

3.5b 2.7b 3.1b 1.3b 1.3b

Explosion-related spinal 

injuries per 1,000 deployed9 0.4b 0.4b 0.4b 0.2b 0.3b

Blast-related thoracolumbar 

burst fractures per 10,000 

soldier years10 0.45c 0.60c 2.08c

a All explosion injuries for a US Army Brigade Combat Team (n = 4,122) deployed during the 2007 troop surge b Additional analysis of cohort described by in Belmont 2012

c Data from August of preceding year to August of specified year

Key Question #1a

No study reported incidence by blast characteristics (ie, primary, secondary, etc.) or injury 

outcomes (eg, pain, amputations, vision loss, cognitive function, functional status, quality of 

life). Three reported incidence by injury site (ie, body location or system injured) (Table 1).

7,9,10 

Two of the studies provided information about specific injury types for the service members 

deployed to Afghanistan or Iraq included in the cohort described by Belmont 2012.8 One study 

identified explosion-related musculoskeletal injuries (upper and lower extremity, spine, and 

pelvis wounds including fractures, soft tissue injuries, joint dislocations, neurologic injuries, and 

traumatic amputations) during a 5 year period.7 The incidence values (per 1,000 deployed 

soldiers) were 3.5 in 2005, 2.7 in 2006, 3.1 in 2007, 1.3 in 2008, and 1.3 in 2009. The other study 

reported on explosion-related spinal injuries finding 0.4 per 1,000 deployed soldiers in 2005, 

2006, and 2007; 0.2 per 1,000 soldiers in 2008; and 0.3 per 1,000 soldiers in 2009.9 The injuries 

included fractures, dislocations, disk displacements, nerve root injuries, and spinal cord injuries. 

Another study looked specifically at combat thoracolumbar burst fractures, a pattern of injury 

that occurs as a result of vertical forces imparted by an explosion beneath an armored vehicle.10

All soldiers who sustained this type of injury while deployed to Iraq or Afghanistan in 2007 to 

2010 were identified through the JTTR and medical records from Landstuhl Regional Medical 

Center. The incidence increased from 0.45 per 10,000 soldier-years in the one-year period 

August 2007-2008, to 0.60 per 10,000 soldier-years in August 2008-2009, and 2.08 per 10,000 

soldier-years in August 2009-2010. The increase in 2009-2010 was largely among soldiers 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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serving in Afghanistan and the authors attributed to increased use of powerful improvised 

explosive devices against newer, up-armored vehicles. The authors speculated that with the 

newer military vehicles, explosives that might have caused deaths in the past were now 

associated with non-fatal burst fracture injuries. 

Key Question #2. Prevalence

The National Institute of Mental Health has defined prevalence as the proportion of a population 

who have (or had) a specific condition in a given time period regardless of when they first 

acquired the condition.12 For this review, we report cumulative data as prevalence. (Table 2)

Explosion-related injuries over a 5-year period (2005-2009) were reported for the Belmont et al

cohort.8 Among 1,992,232 soldiers deployed to Afghanistan or Iraq during that time period, there 

were 5,862 explosion injuries, or 0.29% of deployed soldiers experienced an explosion-related 

injury. Explosion injuries accounted for 74% of injuries. 

Key Question #2a

No studies reported prevalence by blast characteristics (ie, primary, secondary, etc) or injury 

outcomes (eg, pain, amputations, vision loss, cognitive function, functional status, quality of 

life).

Four studies reported injuries to specific body sites or systems (Table 2). Two studies were 

additional analyses of the cohort reported by Belmont et al.

8 The study of musculoskeletal 

injuries reported 4,563 soldiers deployed to Afghanistan or Iraq with explosion-related injuries 

(0.23% of deployed soldiers).7 Of all musculoskeletal injuries, 82% were explosion-related. By 

type of injury, 74% of axial skeleton fractures, 78% of upper extremity fractures, 84% of lower 

extremity fractures, 94% of amputations, 64% of neurologic injuries, 84% of joint dislocations, 

and 85% of soft tissue injuries were blast-related. Another analysis reported there were 650 

soldiers with explosion-related spinal injuries (0.03% of deployed soldiers).9 Of all spinal 

injuries, 75% were explosion-related. Among the 650 with explosion-related spinal injuries, 31% 

(n = 204) had injuries to more than one spinal region. Associated head and neck injuries were 

noted in 57% (n = 132) of soldiers with an explosion-related cervical spine injury. 

The study of thoracolumbar burst fractures in Afghanistan or Iraq reported that over the period 

2007-2010, the rate of blast-related fractures was 2.02 per 10,000 soldier years.10 A 

Congressional Budget Office Working Paper reported major amputations (loss of a limb 

proximal to the wrist or ankle).11 The prevalence was 38 per 100,000 troop years in OEF and

OND and 88 per 100,000 troop years in OEF.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Table 2. Prevalence Data

Outcome 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Explosionrelated 

injuries (any)8 

74% of injuries

0.29% of 1,992,232 deployed

(30.5 per 10,000 deployed)

 

Blast-related 

thoracolumbar burst 

fractures10

2.02 per 10,000 soldier-years

Explosionrelated 

musculoskeletal 

injuries7

82% of musculoskeletal wounds

(14,158 wounds) 

0.23% of 1,992,232 deployed

(22.9 per 10,000 deployed)

Explosionrelated spinal 

injuries9

75% of spinal casualties

0.03% of 1,992,236 deployed

(3.3 per 10,000)

Improvised 

explosive 

device major 

amputations11

Iraq (OEF, OND): 38.3/100,000 troop-years

Afghanistan (OEF): 87.8/100,000 troop-years

Summary of Findings for Key Questions #1 and #2

One study reported explosion injury incidence from Afghanistan and Iraq, finding values ranging 

from 4.5/1,000 deployed in 2005 to 1.7/1,000 deployed in 2009. Another study reported data 

from the Iraq troop surge (2007), finding a high incidence of explosion injury (83/1,000 

deployed in a US Army Brigade Combat Team). Three studies reported blast injury incidence by 

body location (musculoskeletal injuries, spinal injuries, or thoracolumbar burst fractures). No 

study reported incidence by blast characteristics. 

Seventy-four percent of all combat injuries over the period from 2001 to 2011 were due to 

explosions. The prevalence was 30.5 per 10,000 deployed. The prevalence of explosion-related 

musculoskeletal injuries was 23 per 10,000 deployed; the prevalence of explosion-related spinal 

injuries was 3 per 10,000 deployed, the prevalence of blast-related thoracolumbar burst fractures 

was 2 per 10,000 soldier-years, and the prevalence of explosion-related major amputations 

ranged from 4 per 10,000 troop-years in Iraq to 9 per 10,000 troop-years in Afghanistan. No 

study reported prevalence by blast characteristics.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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KEY QUESTION #3: What are the short-term (up to 30 days), mid-term 

(30 days to one year) and long-term (greater than one year) injury 

outcomes (ie, pain, burns, limb loss, vision loss, hearing loss, 

vestibular dysfunction, PTSD, cognitive function, quality of life, 

functional status/employment, other) among US military personnel 

(2001-2014) who have sustained a blast-related TBI versus a non-blast 

TBI or a combined blast/non-blast TBI?

Overview of Studies

We identified 34 studies (36 articles) reporting on outcomes associated with blast versus nonblast related TBI (Table 3). Six studies included data from registries or databases with sample 

sizes ranging from 60413 to 12,521.

14 The remaining studies were clinical cohort studies with 

sample sizes ranging from 1815 to 727.

16

In 26 studies, patients were assessed at a medical facility (typically a DoD or VA hospital). 

Three studies assessed patients in combat zone facilities,17-19 2 included post-deployment 

assessment data,20,21 one included both combat zone and post-deployment data,22 one used a 

mailed questionnaire,23 and location could not be determined for one study.13

The time from exposure to outcome assessment was less than 30 days for 3 studies17,19,24 with 

another study including both an immediate assessment and a follow-up at 6 to 12 months.18 One 

study assessed patients within 12 months of injury (50% within the first month).25 Ten studies 

assessed outcomes between 30 days and one year from exposure and 5 at greater than one year. 

Fourteen studies included any time post-exposure or did not specify a time.

Eighteen studies included only patients with mild TBI (mTBI), one study included only patients 

with moderate or severe TBI,13 2 studies included patients with mild or moderate/severe TBI and 

reported results separately, 12 studies included any TBI (and did not report results by TBI 

severity), and one study reported some outcomes by TBI severity and some outcomes for the 

total sample.20 Additional study characteristics are presented in Appendix C, Table 3.

Table 4 provides an overview of outcomes reported in these studies. The most frequently 

reported outcomes were PTSD, cognitive function, hearing impairment, and vision impairment. 

Few studies reported mortality, quality of life, limb loss, pain, or burn injuries. Findings for each 

outcome are reported below. More detailed outcome data are presented in Appendix C, Tables 4a 

to 4l.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Table 3. KQ3 Overview: Blast versus Non-blast TBI – Population and Study Characteristics

Author, year

Data Source

Sample 

Size

Characteristics

Registry/

Database

Clinical Cohort

Location of Assessment Time Since Exposure TBI Severity

Combat 

Zone

After

Deployment

DoD, VA, 

or Other 

Medical 

Facility

< 30 

days

30 days 

to 1 year > 1 year Any or 

Unclear

Mild

Moderate/

Severe

Mixed

(results not 

reported 

separately)

Akin, 201115 ü 18 ü ü ü

Belanger, 200926 ü 102 ü ü ü ü

Belanger, 201127 ü 390 ü ü ü

Brahm, 200928 ü 192 ü ü ü ü

Clark, 200929 ü 85 ü ü ü

Cockerham, 201330 ü 53 ü ü ü

Collen, 201231 ü 116 ü ü ü

Cooper, 201232 ü 60 ü ü ü

DuBose, 201113 ü 604 ? ? ü ü

Fortier, 201433 ü 56 ü ü ü

French, 201425 ü 579 ü ü ü

Goodrich, 201334

Goodrich, 201435 ü 100 ü ü ü

Hoffer, 200936 ü 127 ü ü ü

Kennedy, 201016 ü 724 ü ü ü

Kontos, 201322 ü 2,813 ü ü ü ü

Lange, 201237 ü 56 ü ü ü

Lew, 201114 ü 12,521 ü ü ü

Lew, 200738 ü 150 ü ü ü

Lippa, 201039 ü 194 ü ü ü

Luethcke, 201117

Blast is primary 

blast; non-blast 

includes secondary, 

tertiary, quaternary, 

and non-blast

ü 82 ü ü

ü
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, year

Data Source

Sample 

Size

Characteristics

Registry/

Database

Clinical Cohort

Location of Assessment Time Since Exposure TBI Severity

Combat 

Zone

After

Deployment

DoD, VA, 

or Other 

Medical 

Facility

< 30 

days

30 days 

to 1 year > 1 year Any or 

Unclear

Mild

Moderate/

Severe

Mixed

(results not 

reported 

separately)

Mac Donald, 201418

Blast is blast plus 

other mechanism of 

head injury

ü 82c üc üc üc

ü

MacGregor, 201120 ü 2,074 ü ü ü ü ü

Maguen, 201240 ü

1,082

(968 for 

PTSD)

ü ü

ü

Mendez, 201341

Mendez, 201342 

Blast is primary blast 

only; non-blast is 

blunt injury

ü 24 ü ü ü

Mora, 200943

Blast is IED 

exposure with 

primary blast injury; 

non-blast is IED 

exposure without 

primary blast injury

ü 19 ü ü ü

Nakase-Richardson, 

201344 ü 106b ü ü ü

Oleksiak, 201245 ü 189 ü ü ü

Pogoda, 201246 ü 9,998 ü ü ü

Reid, 201447 ü 573 ü ü ü

Sayer, 200848 ü 188 ü ü ü

Schneiderman, 

200823 ü 275e ü ü ü

Wilk, 201021 ü 574 ü ü ü

Wojcik 201019 ü 1,388d ü ü ü
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, year

Data Source

Sample 

Size

Characteristics

Registry/

Database

Clinical Cohort

Location of Assessment Time Since Exposure TBI Severity

Combat 

Zone

After

Deployment

DoD, VA, 

or Other 

Medical 

Facility

< 30 

days

30 days 

to 1 year > 1 year Any or 

Unclear

Mild

Moderate/

Severe

Mixed

(results not 

reported 

separately)

Xydakis, 201224 ü 256 ü ü ü a Patients admitted to US Army Institute of Surgical Research burn center

b Patients admitted to Polytrauma Rehabilitation System of Care with a disorder of consciousness (DOC)

c Initial assessment in Germany (n = 123 with TBI); followed 6-12 months post-injury at Washington University (US) (n = 82) d Episodes (TBI hospitalizations with mechanism of injury data)

e Responded to self-administered mail questionnaire

? = unclear
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

28

Table 4. KQ3 Overview: Blast versus Non-blast TBI – Summary of Outcomes

Author, year

Data Source

Sample 

Size

Outcomes Reported

Mortality

PTSD

Pain

Burn

Limb Loss

Vision 

Impairment

Hearing 

Impairment

Vestibular 

Dysfunction

Cognitive 

Function 

Loss

Quality of 

Life

Functional 

Status/

Employment

Other

Registry/

Database

Clinical 

Cohort

Akin, 201115 ü 18 ↔

Belanger, 200926 ü 102 ↔ ↔

Belanger, 201127 ü 390 -

↔Postconcussive 

symptoms

Brahm, 200928 ü 192 ↔

Clark, 200929 ü 85 - ↔ ↔ - ↔ ↔ ↔ ↔

↔Depression

-Any psychiatric 

diagnosis

Cockerham, 201330 ü 53 ↔

Collen, 201231 ü 116 ↔

↔Depression

-Anxiety

MIXED Sleep 

disorders 

Cooper, 201232 ü 60 ↔ ↔Headache

DuBose, 201113 ü 604 ↔

Fortier, 201433 ü 56 ↔TBI severity 

French, 201425 ü 579 ↔Injury severity

Goodrich, 201334

Goodrich, 201435 ü 100 - ↔

Hoffer, 200936 ü 127

↔

VOR

MIXED 

VSR

Kennedy, 201016 ü 724 ↔

Kontos, 201322 ü 2,813 - -

Lange, 201237 ü 56 ↔ ↔Personality

Lew, 201114 ü 12,521  ̄ -

Lew, 200738 ü 150 -
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, year

Data Source

Sample 

Size

Outcomes Reported

Mortality

PTSD

Pain

Burn

Limb Loss

Vision 

Impairment

Hearing 

Impairment

Vestibular 

Dysfunction

Cognitive 

Function 

Loss

Quality of 

Life

Functional 

Status/

Employment

Other

Registry/

Database

Clinical 

Cohort

Lippa, 201039 ü 194 MIXED

↔Postconcussive 

symptoms

Luethcke, 201117

Blast is primary 

blast; non-blast 

includes 

secondary, tertiary, 

quaternary, and 

non-blast

ü 82 ↔ ↔

-

Immediate

↔

Current

↔ ↔

↔Global mental 

health

↔Insomnia

↔Immediate 

headache

 ̄Current 

headache

Mac Donald, 

201418

Blast is blast plus 

other mechanism 

of head injury

ü 82c ↔ ↔ ↔

↔Neurobehavioral & 

neuropsychological 

assessments

↔Depression 

severity

↔Headache 

 ̄Smell 

↔Alcohol misuse 

MacGregor, 201120 ü 2,074

-HNF injuries

↔Extremity 

injuries

-Spine/back 

injuries 

 ̄mTBI

-Moderate & 

severe TBI

Maguen, 201240 ü

1,082 

(968 for 

PTSD)

- ↔Depression

↔Alcohol misuse
Combat Blast Injuries 2001

-2014 Evidence-based Synthesis Program

30

Author, year

Data Source

Sample 

Size

Outcomes Reported

Mortality

PTSD

Pain

Burn

Limb Loss

Vision 

Impairment

Hearing 

Impairment

Vestibular 

Dysfunction

Cognitive 

Function 

Loss

Quality of 

Life

Functional 

Status/

Employment

Other

Registry/

Database

Clinical 

Cohort

Mendez, 201341

Mendez, 201342 

Blast is primary 

blast only; non

-

blast is blunt injury

ü 24

MIXED

↔

↔Post-

concussive 

symptoms

-Psychopathy ↔Behavior

Mora, 200943

Blast is IED 

exposure with 

primary blast 

injury; non-blast is 

IED exposure 

without primary 

blast injury

ü 19a 

↔?

?Injury Severity 

Score

Nakase-

Richardson, 201344

ü 106b MIXED

 ̄

 ̄Recovery of 

consciousness 

(vs other trauma)

Oleksiak, 201245

ü 189↔

Pogoda, 201246

ü 9,998↔Multi-sensory

Reid, 201447

ü 573

-----

-Post-concussive 

symptoms -Sleep ↔Depression

Sayer, 200848

ü 188

↔

-

↔

-

↔

↔

- Injury

-

↔↔

↔

↔Sleep

↔Depression 

Schneiderman, 

200823

ü 275e 

↔Post-

concussive 

symptoms

Wilk, 201021

ü 574↔

↔ MIXED↔ MIXED↔

↔Depression 

MIXED Headache ↔Sleep ↔Alcohol misuse 

Wojcik 201019

ü 1,388

d

?Severity of TBI

Xydakis, 201224

ü 256?Severity of TBI
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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VOR = vestibular-ocular reflex; VSR = vestibular-spinal reflex a Patients admitted to US Army Institute of Surgical Research burn center

b Patients admitted to Polytrauma Rehabilitation System of Care with a disorder of consciousness (DOC)

c Episodes (TBI hospitalizations with mechanism of injury data) d Initial assessment in Germany (n = 123 with TBI); followed 6-12 months post –injury at Washington University (US) (n = 82) e Responded to self-administered mail questionnaire f Significance of findings is across blast exposure groups: 0 blasts, 1 blast, 2 blasts, 3 blasts, 4-10 blasts

- Higher prevalence or more severe in blast TBI group;  ̄ Higher prevalence or more severe in non-blast TBI group; ↔ Blast and non-blast groups similar; ? P value not 

reported; MIXED Multiple tests with mixed results
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Mortality (k = 2) (Appendix C, Table 4a) 

< 30 days post-exposure

One study included service members receiving polytrauma/TBI inpatient rehabilitation at a VA 

polytrauma rehabilitation center (PRC).48 Of 188 patients studied, 106 had a blast exposure and 

82 did not; 97% had a TBI. Mortality was 3% in the blast group and 1% in the non-blast group. 

Mortality was similar between the groups (P = .63). 

Other

A second study was based on data from the JTTR.

13 Time from exposure to evaluation was not 

specified. The 604 patients included in the study had an isolated TBI: 374 were associated with a 

blast exposure, 118 from gunshot, and 112 following blunt trauma. Mortality was 9% in the blast 

group, 7% in the gunshot group, and 10% in the blunt trauma group. Relative to the blunt trauma 

group, the odds ratios for mortality in the blast and gunshot groups, respectively, were 0.66 (95% 

CI 0.31, 1.41) and 0.60 (95% CI 0.19, 1.89), respectively. 

Posttraumatic Stress Disorder (PTSD) (k = 16) (Appendix C, Table 4b)

< 30 days post-exposure

One study reported short-term results.17 Eighty-two military and civilian contractors were 

evaluated within 72 hours of injury in an outpatient TBI clinic at a forward-deployed combat 

support hospital (CSH). The blast and comparator groups had similar Posttraumatic Stress 

Disorder Checklist (PCL) scores. The blast group included only those with primary blast 

exposure while the comparator group included secondary, tertiary, quaternary, and non-blast 

exposures. 

30 to 365 days post-exposure

Seven studies evaluated patients 30 days to one year after exposure with 5 including only 

patients with mTBI16,21,32,43,48 and 2 including any TBI severity.18,34,35 Studies used variable 

definitions of non-blast injury (eg, some studies included secondary blast injuries as non-blast

injuries) which could affect the prevalence and outcomes of estimates. Five studies reported the 

percentage of patients with a PTSD diagnosis. In 4 of the 5 studies, the blast and non-blast 

groups were similar.

16,18,21,43 One was a study of 724 patients screened and identified with mTBI 

at a military medical center.16 Another was a small study (n = 19) of mTBI patients treated at a 

military burn center. Blast cases had experienced an improvised explosive device (IED) primary 

blast while non-blast cases had IED exposure without primary blast injury.43 The third was a 

study of 82 patients, 52 with blast exposure. Blast cases in this study had experienced a blast 

explosion plus another mechanism of head injury.18 The fourth study included 574 patients who 

reported concussion. The patients were further categorized as having experienced a loss of 

consciousness or a change in consciousness. Prevalence of PTSD was similar for blast and nonblast groups in both subgroups.21 The study finding higher prevalence of PTSD in the blast TBI 

group was designed to assess vision outcomes but also reported PTSD prevalence in the 100 

patients. The prevalence of PTSD was 62% in the blast group and 20% in the non-blast group 

(P<.001).35
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Two studies reported PCL scores finding similar scores for blast and non-blast TBI groups.16,32

One was a study of 60 patients referred to a TBI clinic at an Army medical center for 

neuropsychological testing32 and the other was a study of 724 patients described above.16 A third 

study with 188 patients (described in the Mortality outcomes section) reported the prevalence of 

PTSD symptoms was higher in the blast TBI group (42% vs 24%, P<.01).48

In another study, the blast TBI patients (n = 298) were evaluated less than 365 days after 

exposure and the non-blast TBI patients (n = 92) were evaluated more than 365 days after 

exposure.27 PCL scores were significantly higher in the blast TBI group (42 vs 37, P = .047). 

> 365 days post-exposure

Two studies reported PTSD findings at more than 365 days after exposure. Among 116 soldiers 

with combat-related TBI (85% mTBI) receiving care at an Army medical center, the percentage 

of patients with a comorbid diagnosis of PTSD was similar for the blast and non-blast groups.31

A study of 339 patients referred for TBI screening in the VA system reported that PCL total 

scores were similar for the blast and non-blast groups but a higher percentage of patients with 

blast-related mTBI had a PCL score of 50 or higher (65% vs 45%, P<.05).39

Other

Five studies reported PTSD findings at any time post-exposure or did not specify the 

time.22,26,29,40,47 One study of 128 active duty personnel and Veterans admitted to a PRC (80% 

with TBI) found a higher prevalence of PTSD in the blast group (45% vs 12%, P<.05).29 A 

registry study of 2,813 US Army Special Operations Command (USASOC) personnel who 

completed Web-based evaluations in both deployed and non-deployed settings found 

significantly higher odds of clinical levels of PTSD symptoms in the blast mTBI group compared 

to the blunt mTBI group (OR 2.12 [95% CI 1.68, 2.66]).22 A study of 968 Veterans reported a 

higher odds of a positive PTSD screen in Veterans with a blast-only head injury compared to 

TBI with no head injury (OR 4.7 [95% CI 2.9, 7.7]) or a blast plus other mechanism of injury 

compared to TBI with no head injury (OR 6.5 [95% CI 4.6, 9.3]).40 A study of 102 VA patients 

reported similar PCL scores between blast and non-blast groups.26 

A study of 573 male service members with combat-related mTBI evaluated one to 24 months 

post-injury reported a significant difference in PCL scores across self-reported blast exposure 

groups (0 blasts, 1 blast, 2 blasts, 3 blasts, or 4 to 10 blasts).47 Subsequent analyses showed only 

that the PCL score for the group exposed to 4 to 10 blasts was significantly higher than the score 

for the group exposed to one blast. The study of USASOC personnel also reported that PTSD 

symptom scores increased significantly with an increased number of diagnosed blast-related 

mTBIs.22 The odds ratio for clinical levels of PTSD symptoms associated with 3 or more blastrelated mTBIs compared to one blast mTBI was 1.74 (95% CI 1.19, 2.54). The odds ratio for 3 

or more blast-related mTBIs compared to 2 blast-related mTBIs was not significant (OR 1.32 

[95% CI 0.82, 2.14]). 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Pain (k = 3) (Appendix C, Table 4c)

30 to 365 days post-exposure

Impairment associated with pain was similar for blast and non-blast mTBI groups in a study of 

188 Veterans.48 The percentage of US soldiers reporting back pain or arm, leg, or joint pain was 

similar between blast and non-blast mTBI groups and subgroups experiencing either loss of or 

change in consciousness.21 The percentage of soldiers with stomach pain was significantly higher 

for the non-blast mTBI group among those with a change in consciousness (15% vs 6%, P = .01) 

but not those with a loss of consciousness. 

Other

A third study of 128 patients admitted to a PRC (80% with TBI) did not specify the time postexposure. Pain intensity scores and the number of pain sites were similar for blast and non-blast 

TBI patients.29

Burns (k = 3) (Appendix C, Table 4d)

30 to 365 days post-exposure

The study of 188 Veterans assessed 30 days to one year post-exposure reported a higher 

percentage of patients with skin or soft tissue burn injury in the blast-related mTBI group 

compared to the non-blast group (13% vs 4%, P<.05).48 The small study (n = 19) of mTBI 

patients treated at a military burn center reported the percentage of total body surface area 

(TBSA) burned. The mean TBSA for the blast cases (IED primary blast) was 8.1% compared to 

17.0% for the non-blast cases (IED without primary blast injury).43

Other

The study of 128 patients admitted to a PRC (described above) reported a similar percentage of 

patients with a burn diagnosis in the blast and non-blast groups.29

Limb Loss (k = 2) (Appendix C, Table 4e)

30 to 365 days post-exposure

In the study of outcomes at 30 days to one year post-exposure (n = 188), the percentage of 

Veterans with an amputation was similar between blast and non-blast exposures (9% vs 6%) with 

10 amputations in the blast group and 2 in the non-blast group.48 

Other

The second study reported a significantly higher percentage of amputations in the blast group 

(16% vs 3%, P<.05).29

Vision Impairment (k = 8) (Appendix C, Table 4f)

< 30 days post-exposure

The study of patients assessed at a forward-deployed CSH reported blast and comparator groups 

experienced a similar incidence of vision loss symptoms both immediately after the injury and 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

35

when assessed within 72 hours of the exposure.17 Blast was defined as primary blast exposure in 

this study; the comparator group included other blast exposures and non-blast injuries. 

30 to 365 days post-exposure

The study of 188 Veterans (described above) reported a significantly higher incidence of eye 

injuries in the blast-related mTBI group (47% vs 26%, P<.01) but the groups were similar in 

incidence of vision impairment (58% vs 46%, P not significant).48 The study of 100 Veterans 

admitted to a PRC and undergoing eye examinations reported the blast and non-blast groups 

were similar in percentage with ocular injury, monocular vision, vision complaints, reading 

complaints, and poor visual acuity (in the worse eye). More patients in the blast group reported 

light sensitivity (67% vs 33%, P = .002).34,35 Another study of 53 Veterans reported a similar 

incidence of dry eye disease between blast and non-blast TBI patients. Measures of tear 

production and tear osmolarity were also similar.30

Other

Four studies did not specify the time post-exposure or included any time post-injury. A study of 

polytrauma inpatients (n = 68) and outpatients (n = 124) reported similar vision outcomes 

(subjective visual complaint, ocular injury, legally blind status) between blast and non-blast 

groups for the outpatients while for the inpatients one of the outcomes, ocular injury, was 

significantly higher for the blast group (44% vs 9%, P = .04).28 The study of 573 male service 

members evaluated at one to 24 months post-injury reported a significant difference across blast 

exposure groups for scores on the “vision problems, blurring, trouble seeing” component of the 

Neurobehavioral Symptom Inventory (NSI).47 The highest score was observed in the group with 

4 to 10 blast exposures. The study of 128 patients admitted to a PRC (described above) reported 

similar percentages with eye injury in the blast and non-blast groups.29 A database study of 

12,521 patients with deployment-related TBI reported a higher percentage of patients with visual 

impairment only in the non-blast group (16% vs 9%, P<.001).14

Hearing Impairment (k = 9) (Appendix C, Table 4g)

< 30 days post-exposure

The study of patients assessed at a forward-deployed CSH reported that a higher percentage of 

blast-exposed patients experienced hearing loss symptoms immediately after the injury (53% vs 

17%, P = .001) but the groups were similar when assessed within 72 hours of the exposure.17 The 

blast group included only primary blast-exposed patients.

30 to 365 days post-exposure

The study of 188 Veterans (described above) reported a higher percentage of patients in the blast 

group with otologic injury (46% vs 23%, P<.01), hearing loss (48% vs 33%, P<.05), and tinnitus 

(26% vs 12%, P<.05).48 The study of soldiers with concussion reported a higher percentage 

reporting ringing in ears in the blast group among those who experienced loss of consciousness 

(34% vs 15%, P = .02) but not among those who experienced change in consciousness (22% vs 

17%, P = .32).21 In the study of 82 patients where blast was defined as blast plus another 

mechanism of head injury, the percentage of patients reporting hearing deficit was similar for the 

blast and non-blast groups.18
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Other

Among the studies that did not specify a time post-exposure, the study of 128 patients admitted 

to a PRC found the percentage with “hearing problems” was similar for blast and non-blast 

groups.29 The database study with 12,521 patients reported greater auditory impairment only in 

the blast group compared to the non-blast group (33% vs 23%, P<.001). The percentages of 

patients with dual sensory impairment were similar between groups (35% vs 30%).14 An earlier, 

smaller study from this group (150 Veterans admitted for inpatient rehabilitation) found a greater 

percentage of patients in the blast group with hearing loss (62% vs 44%, P = .04) and tinnitus 

(38% vs 18%, P = .007).38 The study of 573 male service members evaluated at one to 24 months 

post-injury reported a significant difference across blast exposure groups for scores on the 

“hearing difficulty” component of the NSI.47 The highest score was observed in the group with 4 

to 10 blast exposures. In a study of 198 Veterans with confirmed mTBI, “hearing difficulty” 

(from the NSI) was similar for blast and non-blast groups.45

Vestibular Dysfunction (k = 6) (Appendix C, Table 4h)

< 30 days post-exposure

The study that evaluated 82 patients at a forward-deployed CSH reported that blast (primary 

blast only) and comparator (other blast and non-blast exposure) groups were similar in balance 

and dizziness symptoms both immediately following the injury and at the time of assessment (72 

hours or less post-exposure).17 

30 to 365 days post-exposure

The studies evaluating 188 Veterans48 or 574 soldiers with concussion21 at 30 days to one year 

post-exposure reported blast and non-blast groups were similar in balance/equilibrium 

impairment48 and dizziness or balance problems.21 In the latter study, the groups were similar 

whether the patients had experienced loss of or change in consciousness.21

Other

Two studies did not report time since exposure and one included assessments at one to 24 

months post-exposure. In one, a study of 18 Veterans referred to a VA Vestibular/Balance 

Laboratory for complaints of dizziness and/or imbalance, the mean Dizziness Handicap 

Inventory score for the blast-related mTBI group was in the “severe” range while the mean for 

the non-blast group was in the “moderate” range.15 No statistical significance was reported. The 

percentage of patients with abnormal results for the Sensory Organization Test was similar 

between groups. Another study, conducted at a Naval medical center, included tests for 

vestibular-ocular reflex (VOR, n = 55) and vestibular-spinal reflex (VSR, n = 72).36 Some 

“descriptive differences” were noted between blast and blunt force groups in the VOR study. In 

the VSR study, there was a trend toward better scores on the Sensory Organization Test in the 

blunt exposure group while significantly more patients in the blast exposure group had abnormal 

latency times on a Motor Control Test. The study of 573 male service members evaluated at one 

to 24 months post-injury reported a significant difference across blast exposure groups for scores 

on the “loss of balance” component of the NSI.47 The highest score was observed in the group 

with 4 to 10 blast exposures. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Cognitive Function Loss (k = 10) (Appendix C, Table 4i)

< 30 days post-exposure

The study from the forward-deployed CSH reported that blast (primary blast only) and 

comparator (other blast and non-blast exposures) groups had similar cognitive function scores 

when assessed at 72 hours or less post-exposure.17 

30 to 365 days post-exposure

In a study of 60 service members referred to an Army medical center for neuropsychological 

testing, the cognitive functioning assessment yielded similar results for the blast and non-blast 

groups.32 Another study of patients evaluated at an Army medical center following medical 

evacuation from the OEF/OIF combat theater found significant between-group (blast/non-blast) 

differences for 2 of 12 measures in a neurocognitive test battery with poorer performance by the 

non-blast group.37 A study of 106 patients admitted to a polytrauma rehabilitation clinic with a 

disorder of consciousness found blast and non-blast groups had similar changes in cognitive 

scores from admission to discharge. The blast group improved by one point on an 8-point scale 

while the non-blast group with penetrating trauma improved by 2 points and the non-blast group 

with other trauma improved by 3 points. Similar results were observed for the cognitive 

component of the Functional Independence Measure (FIM).44 The study of 188 Veterans 

receiving inpatient VA polytrauma/TBI inpatient rehabilitation services (described previously) 

reported that blast and non-blast groups were similar in the percent reporting cognitive 

impairment (88% vs 93%).48 The study of 574 soldiers with concussions reported that similar 

percentages of the blast and non-blast groups that experienced loss of consciousness had memory 

problems (31% vs 30%, P = 1.0) or concentration problems (32% vs 34%, P = .85). In the blast 

and non-blast groups that experienced a change in consciousness, there was a higher percentage 

that experienced memory problems in the non-blast group (31% vs 18%, P = .01) while the 

percentage with concentration problems was similar (35% vs 24%, P = .05).21

> 365 days post-exposure

One study assessed cognitive function at more than 365 days post-exposure.42 Three instruments 

were used and results were mixed. The blast group (defined for this study as primary blast force 

only) performed worse than the non-blast (blunt force) group on a serial addition test but the 

groups were similar on tests of “executive operations” and mental flexibility/decision-making. 

Other

In 2 of the 4 studies reporting cognitive function outcomes but not specifying a time postexposure, blast and non-blast groups had similar outcomes. One study enrolled 102 Veterans and 

reported similar scores on 4 neuropsychological tests.26 The other enrolled 128 active duty 

personnel and Veterans and reported similar scores on a test of cognitive deficits associated with 

recovery from brain injury.29 The third study, a database study of 2,813 USASOC personnel 

(described above), reported poorer performance in the blast mTBI group on tests of visual 

memory, visual processing speed, and reaction time. The groups were similar on the verbal 

memory test.22 The fourth study, with 573 male service members evaluated at one to 24 months 

post-injury, reported a significant difference across blast exposure groups for scores on the 

cognitive element of the NSI.47 The highest score was observed in the group with 4 to 10 blast 

exposures. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Quality of Life (k = 1) (Appendix C, Table 4j)

> 365 days post-exposure

One study reported quality of life based on responses to the Health-Related Quality of Life 36-

item Short Form (SF-36).42 Participants were 24 Veterans undergoing a Second Level TBI 

evaluation at a VA medical center and mean time from exposure was over 4 years. Blast-related

injury was defined as injury due to primary blast force. SF-36 scores (Physical Composite, 

Mental Composite, and all sub-scales) were similar for the blast and non-blast (blunt) groups. 

Functional Status/Employment (k = 5) (Appendix C, Table 4k)

30 to 365 days post-exposure

One study of 82 active duty US military evacuated from Iraq and Afghanistan and followed up in 

the US 6 to 12 months later found that blast and non-blast TBI groups were similar on a global 

outcome measure of disability.18 The percentages of patients categorized as having moderate to 

severe disability were also similar (77% blast, 79% non-blast, P = .84). In this study, participants 

with a blast injury also had some other mechanism of head injury. 

A study of 122 patients admitted to VA polytrauma care with a disorder of consciousness 

assessed functional independence at admission and discharge.44 There was no change over time 

for the blast TBI group or for the non-blast TBI group that had experienced penetrating trauma. 

There was a significant change over time for the non-blast TBI group that had experienced 

“other trauma” relative to both the blast injury and penetrating trauma groups. In a similar 

population of 188 service members, 62% of the blast injury group and 65% of the non-blast 

injury group reported motor functioning impairment (P not significant).48

The study of 574 soldiers with concussion data reported on workdays missed.21 The percentages 

reporting 2 or more missed workdays due to illness were similar in the blast and non-blast mTBI 

groups for the subgroups reporting loss of consciousness (21% vs 23%, P = .83) or change in 

consciousness (17% vs 10%, P = .11). 

Other

One study that did not specify the time since exposure reported functional independence scores.29

The scores for the blast and non-blast groups were similar.

Other Outcomes (Appendix C, Table 4l)

Depression (k = 7) 

Seven studies reported on either depression diagnosis21,29,31,40 or depression 

symptoms/severity.

18,47,48 All studies found blast and non-blast TBI groups to be similar. Three 

studies assessed outcomes 30 to 365 days post-exposure,18,21,48 one at more than 365 days,31 and 

3 at unspecified or any time post-exposure.29,40,47

Insomnia (k = 5) 

In 3 studies, blast and comparator groups had similar scores for insomnia severity (assessed less 

than 30 days post-exposure),17 sleep impairment (assessed 30 to 365 days post-exposure),48 and 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

39

sleep problems (also at 30 to 365 days post-exposure).21 A study of 573 male service members 

evaluated at one to 24 months post-injury reported a significant difference across blast exposure 

groups for scores on the “difficulty falling or staying asleep” component of the NSI with the 

highest score in the group with 4 to 10 blast exposures.47 One study of 116 soldiers receiving 

care at an Army medical center and assessed more than 365 days post-exposure reported higher 

levels of insomnia in the blast injury group (63% vs 40%, P = .02) but fewer with a diagnosis of 

obstructive sleep apnea syndrome (26% vs 54%, P = .003) and lower mean scores on the 

Epworth Sleepiness Scale (9 vs 11, P = .04).31 

Headache (k = 4)

Two studies, both assessing outcomes at 30 to 365 days post-exposure, reported that blast and 

non-blast TBI group were similar on measures of headache impact32 or migraine disability.18

Another study found similar percentages of patients in the blast (primary blast only) and nonblast groups with headache symptoms immediately post-injury (70% vs 81%, P = .25) but within 

72 hours, there was a higher percentage with headache symptoms in the comparator (other blast 

and non-blast exposure) group (53% vs 83%, P = .003).17 A fourth study reported a higher 

percentage of patients with headache in the blast with loss of consciousness group than the nonblast loss of consciousness group (40% vs 23%, P = .04) while the percentages of patients with 

headache in the blast and non-blast change in consciousness groups were similar (21% vs 18%, P 

= .57). Outcomes were assessed 30 to 365 days post-exposure.21

Severity of TBI (k = 4)

Four studies provided a measure of whether TBI severity differed between blast and non-blast 

exposures. A database study of 1,388 soldiers hospitalized with a TBI and a known associated 

mechanism of injury, found that 55% of explosion-related TBIs were Type 1 (most severe), 39% 

were Type 2, and 6% were Type 3 (least severe).19 For non-blast TBIs the corresponding 

percentages were 43%, 50%, and 6%. Alternatively, 68% of the Type 1 (most severe) TBIs, 56% 

of the Type 2, and 63% of the Type 3 (least severe) were explosion-related. Statistical 

significance was not reported.

A study of polytrauma patients with combat-related closed head injuries (blunt or blast 

mechanism) requiring immediate evaluation at an Army medical center in the US reported that 

the percentages of patients with mTBI (68% of blast mechanism injuries, 58% of blunt 

mechanism injuries, P = .21), moderate TBI (28% vs 33%, P = .51), or severe TBI (5% vs 9%, P 

= .32) were similar for the blast mechanism and blunt mechanism groups.24

In a larger, database study (n = 2,074) of injured personnel who completed post-deployment 

health assessments within 365 days of injury, there were significant differences between the blast 

and non-blast groups.20 Of 1,852 with mTBI, 98% had a blast injury and 2% had a non-blast 

injury. Of 90 with moderate TBI, 84% had a blast injury and 16% had a non-blast injury. Of 143 

with severe TBI, 67% had a blast injury and 33% had a non-blast injury. Alternatively, of 1,987 

with a blast injury, 92% had mTBI (vs 34% of the 87 with a non-blast injury), 4% had moderate 

TBI (vs 16% of the non-blast group), and 4% had severe TBI (vs 50% of the non-blast group). 

In one study of 56 Veterans with military TBI assessed more than 365 days post-exposure, the 

percentages of patients in the blast and non-blast groups with Type 1 TBI (most severe), Type 2 

TBI, or Type 3 TBI (least severe) were similar.33 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

40

Alcohol Misuse (k = 3)

Blast and non-blast groups were similar regarding alcohol misuse in 3 studies that reported this 

outcome. One was a study of 82 active duty US military evacuated from Iraq or Afghanistan 

with follow-up assessment 6 to 12 months later.18 Blast-exposed service members had also 

experienced another mechanism of head injury. Another was a study of Veterans (n = 968 

completing the alcohol misuse evaluation) that did not specify the time from blast exposure to 

assessment.40 The third was the study of 574 with concussion (either loss of consciousness or 

change in consciousness) and outcomes assessed 30 to 365 days post-exposure.21

Post-concussive Symptoms (k = 5) 

Five studies reported that blast and non-blast groups were similar on measures of postconcussive symptoms including a study of 339 Veterans with mTBI,39 a study of 390 Veterans 

with mTBI,27 a study of 24 Veterans that defined blast injury as primary blast only and non-blast 

as blunt force injury,42 and a survey study with 275 reporting mTBI.23 Two of the studies 

assessed outcomes more than 365 days post-exposure;39,42 in the survey study, participants were 

more than 30 days post-exposure.23 In the other study, the blast TBI patients (n = 298) were 

evaluated less than 365 days after exposure and the non-blast TBI patients (n = 92) were 

evaluated more than 365 days after exposure.27 A fifth study, with 573 male service members 

evaluated at one to 24 months post-injury, reported a significant difference across blast exposure 

groups for scores on the NSI.47 The highest score was observed in the group with 4 to 10 blast 

exposures and scores in that group were significantly different from the groups with no blast 

exposure or exposure to one or 2 blasts. 

Injury Severity (k = 1)

A study of 579 male service members evaluated within 12 months of injury categorized severity 

of bodily injuries (excluding injury to the brain) as minor, moderate, serious, or severe/critical.25

Severity of injury was not related to mechanism (blast versus non-blast) of injury. 

Multisensory Impairment (k = 1)

A study of 9,998 Veterans (95% male) completing the VA comprehensive TBI evaluation 

(CTBIE) assessed multisensory impairment – the co-occurrence of self-reported auditory, visual, 

and vestibular impairment.46 Relative to those with no reported etiology of injury, the odds ratios 

for predicting multisensory impairment were 1.00 (95% CI 0.80, 1.25) for those with one or 

more non-blast injuries and 1.03 (95% CI 0.84, 1.25) for those with one or more blast injuries. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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KEY QUESTION #3A: What are the short-term (up to 30 days), midterm (30 days to one year) and long-term (greater than one year) 

injury outcomes among US military personnel (2001-2014) who have 

sustained a blast-related TBI according to blast characteristics?

Few studies reported outcomes according to blast characteristics. One study of hearing outcomes 

in Veterans with confirmed mTBI reported findings for subgroups based on the type of blast 

injury (primary [n = 62] or secondary [n = 11]). Time since exposure was not reported. Hearing 

difficulty scores were similar for the 2 subgroups (2.1 for the primary blast group, 1.8 for the 

secondary blast group). A score of one represented mild and a score of 2 moderate hearing 

difficulty. The percentage of patients with a score of greater than one was also similar (94% 

primary, 100% secondary).45

Three studies defined blast injury as primary blast force only.17,41-43 In one of these studies, 

mTBI patients were evaluated at a forward-deployed CSH within 72 hours of injury.17 The 

comparator group included patients experiencing secondary, tertiary, and quaternary blast 

injuries along with injuries not involving blasts. The blast group was similar to the comparator 

group for most outcomes (PTSD symptoms, vision symptoms, hearing symptoms at the time of 

assessment, vestibular dysfunction symptoms, cognitive function, insomnia, global mental 

health, and headache immediately following injury). The blast group reported more or moresevere hearing symptoms and lesser headache symptoms at the time of assessment.

The second study reported outcomes for 24 Veterans assessed at a mean of 4 years postexposure.

41,42 Of the 12 “blast-injury” (primary blast) subjects, 10 reported the blast was less 

than 10 feet from their location at the time of the blast, one reported less than 30 feet, and one 

reported less than 50 feet. The blast group was similar to the non-blast (blunt force) group on 

measures of quality of life, post-concussive symptoms, personality, and behavior. Scores on a 

measure of interpersonal behaviors associated with psychopathy were higher for the blast group. 

Results were mixed for cognitive outcomes with the blast group scoring poorer on one measure 

and blast and non-blast groups being similar on 2 measures. 

The third study evaluated 19 mTBI patients treated at a military burn center 30 to 365 days postexposure.43 Six had primary blast injury associated with an IED and 13 had been wounded in an 

IED explosion but had not sustained a primary blast injury. The prevalence of PTSD was similar 

for the blast and non-blast groups. The mean injury severity score was lower in the blast group 

(7.8 vs 15.0) as was the measure of burn severity (TBSA, 8.1% vs 17.0%) but it was not reported 

if the differences were significant.

Summary of Findings for Key Question #3

In 34 studies of injury outcomes among military personnel sustaining a blast or non-blast TBI, 

we found blast and non-blast groups to be similar in terms of mortality, pain, vision loss, 

vestibular dysfunction, functional ability, depression, sleep disorders, alcohol misuse, and postconcussive symptoms. The results were consistent across studies despite the fact that these 

studies varied in sample size, location of assessment, time from exposure to assessment, and 

level of TBI severity.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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There were less consistent findings for some outcomes. A diagnosis of PTSD or PTSD symptom 

severity was higher in the blast groups in 7 studies. An additional 8 studies found the blast and 

non-blast groups to be similar and one reported mixed results for different ways of reporting 

PTSD. Four studies reported greater hearing loss in the blast injury group while 3 other studies 

reported the blast and non-blast groups were similar. Two reported mixed results; one of these 

studies looked at immediate post-injury hearing loss and current hearing loss (with current 

defined as within 72 hours of injury) and reported greater hearing loss in the blast group early 

post-injury but no difference at the later assessment. Cognitive outcomes also were less 

consistent. Five studies reported that blast and non-blast groups were similar, 2 reported greater 

cognitive impairment in the blast group, and 3 reported mixed results across different measures 

or across subgroups within the study. For the headache outcome, 2 studies reported that the blast 

and non-blast groups were similar and 2 reported mixed results depending on time of assessment 

or state of consciousness following the exposure. 

Other outcomes were rarely reported making conclusions difficult. Three studies reported burn 

and 2 reported limb loss. One study reported an increased percentage of patients with burn 

injuries in the blast group compared to the non-blast group while another reported the 

percentages with a burn diagnosis were similar in the 2 groups. The third reported that the total 

body surface area effected was similar in blast and non-blast TBI groups admitted to a burn 

center. One study reported an increased number of amputations in the blast group while the other 

reported that the groups were similar. Level of quality of life was reported in just one study with 

blast and non-blast groups similar. 

There is little data on outcomes according to blast characteristics. One study reported similar 

hearing outcomes for groups who experienced either primary or secondary. Three studies that 

defined blast injury as due to primary blast force reported few differences between their blast 

injury group and comparator groups. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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SUMMARY AND DISCUSSION

SUMMARY OF EVIDENCE BY KEY QUESTION

Key Questions 1 and 1a – Incidence

The published literature provides limited information about the true incidence and 

prevalence of blast-related injuries experienced by US military personnel. Findings are 

likely influenced by assessment and reporting methods. 

The reported explosion injury incidence ranged from 4.5/1,000 deployed in 2005 to 

1.7/1,000 deployed in 2009. 

During the Iraq troop surge (2007) explosion injury incidence was particularly high 

(83/1,000 deployed in a US Army Brigade Combat Team). 

Musculoskeletal explosion injury incidence (fractures, amputations, neurological injuries, 

joint dislocations, and soft tissue injuries) ranged from 3.5/1,000 deployed in 2005 to 

1.3/1,000 deployed in 2009. 

Spinal injury incidence (fractures, dislocations, nerve root injuries, spinal cord injuries) 

ranged from 0.18/1,000 deployed in 2008 to 0.40/1,000 deployed in 2005. 

Thoracolumbar burst fracture incidence was low (0.45 to 2.1 per 10,000 soldier years 

between 2008 and 2010) but higher in Afghanistan than Iraq and increased over the study 

period. 

No study reported incidence by blast characteristics.

Key Question 2 and 2a – Prevalence

Nearly three-quarters of all combat injuries over the period from 2005 to 2009 (31 per 

10,000 deployed) were due to explosions. 

A high proportion of musculoskeletal injuries (82%; 23 per 10,000 deployed) and spinal 

injuries (75%; 3 per 10,000 deployed) between 2005 and 2009 were due to explosions. Of 

the musculoskeletal injuries, 80% of axial skeletal and extremity fractures, 94% of 

amputations, and 85% of soft tissue injuries were explosion-related. Another study 

reported explosion-related amputations in 4 per 10,000 troop-years (Iraq) and 9 per 

10,000 troop-years (Afghanistan) over the period from 2001 to 2011. 

No study reported prevalence by blast characteristics. 

Key Question 3

The published literature provides limited information on outcomes associated with blast 

versus non-blast TBI experienced by US military personnel. Definitions of blast/nonblast injury, assessment of outcomes, and reporting methods vary and often are based on 

small selected groups. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Blast and non-blast TBI groups had similar rates of pain, vision loss, vestibular 

dysfunction, functional ability, depression, sleep disorders, alcohol misuse, and postconcussive symptoms. 

Comparative outcomes in individuals with blast versus non-blast TBI were inconsistent 

across studies with regard to PTSD diagnosis or symptom severity, hearing loss, 

cognitive function, and headache in blast and non-blast TBI groups. 

Mortality, burn injuries, limb loss, and quality of life were infrequently reported in 

studies comparing blast versus non-blast TBI. 

Results were consistent across studies that varied by location of assessment (combat 

zone, medical facility), time from exposure to assessment (< 30 days, 30 days to one 

year, or > one year), and level of TBI severity, although the most studies were small, 

clinical cohort studies, with mTBI patients evaluated at a DoD or VA medical facility.

There is little data on outcomes among those with TBI according to blast characteristics.

DISCUSSION 

Numerous studies have reported combat casualties but do not provide a denominator to allow for 

determination of true incidence or prevalence in the deployed population at risk.49 For example, 

Ivey et al reported that 2,049 of 23,797 wounded US military personnel documented in the JTTR 

from January 2003 to May 2011 sustained thoracic injuries, a “prevalence” of 8.6%.50 They 

further note that an explosive device was the source of injury for 62% of the thoracic injuries. 

However, these data do not allow a true determination of prevalence of thoracic injuries 

associated with explosive devices among deployed service members. Our literature search 

identified studies like the Ivey et al study for deaths (Eastridge 2012) and other types of injuries 

including spinal column, craniomaxillofacial, colorectal, ocular, otologic, and extremity.51-56 

Similarly, we identified a recent systematic review and meta-analysis reporting the “prevalence” 

and characteristics of battle casualties in Iraq and Afghanistan.57 The review included 8 studies 

spanning 2001 to 2013. Four of the studies are included in our review; the remaining 4 studies 

would not have been eligible for our review because they were either single facility or short-term

studies, not published in English, and/or not predominantly US soldiers. Different studies 

addressed the casualty classifications (died of wounds, killed in action [KIA], wounded in action, 

and returned to duty) differently (eg, one study included only KIA; 2 other studies excluded 

KIA) but the results of all 8 studies were combined. Of 19,671 battle casualties, 14,056 (72%) 

were caused by blasts but, again, no denominator of deployed service members was provided. 

The DoDTR (formerly the JTTR) is recognized as the best available source of data for the study 

of US military combat injuries, but it is not without limitations.7 The DoDTR provides data on 

all combat casualty cases initially entering the Joint Theater Trauma System at Level III medical 

facilities (combat zone). Information is added to the DoDTR as the service member moves to an 

out-of-theater facility and ultimately to a facility in the United States (if required for their care). 

Disadvantages of the DoDTR include variations in the reliability of the data entered by nonresearchers involved in the delivery of care, absence of data on service members killed in action 

or returned to duty (ie, not medically evacuated), and absence of data on US troops treated at 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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North Atlantic Treaty Organization Facilities prior to late 2008.

7,50 Furthermore, in 2007, the 

system for classifying mechanism of injury used in the JTTR was changed and injuries are now 

classified as primarily blunt or penetrating. As a result, blast injury is now less frequently 

reported.50

Few studies of blast incidence or blast-related TBI outcomes report any of the important 

characteristics of a blast injury: how far the individual was from the blast, whether they 

experienced a blast wave, whether there was loss of consciousness or altered consciousness, 

whether there was amnesia (and length of time), and whether there was additional trauma.58

There have been attempts to document this information, however. Data from 367,555 service 

members who completed a Post-Deployment Health Assessment (PDHA) that included questions 

about possible TBI events experienced during deployments from 2012 to 2015 showed that 

45.7% with a positive TBI screen experienced a blast or explosion.59 Among those who reported 

the distance from the blast, the majority were less than 25 meters away. Over 30% reported 

receiving more than one concussive event during the deployment. Among those with a positive 

TBI screen, 11.5% reported 3 or more events. 

We found no reports of blast injuries associated with different combat roles. One combat role 

considered to place soldiers at higher risk of injury due to repeated low-level primary blast 

exposure is that of breacher. Breachers place explosives on structures where access is needed and 

then stand at a “safe” distance away during the explosion. A study of US Marines enrolled in a 2-

week Breacher Training Course focused on auditory and vestibular effects.60 Clinically 

significant hearing loss was noted while the vestibular effects were “unremarkable.” A similar 

study enrolling US Marine instructors measured effects on vision.61 The analysis included 9 

breacher instructors (estimated to be exposed to 500 to 600 “low-level” blasts each year of a 2-

to-3-year assignment) and a control group of 4 breacher engineers (not exposed to blasts) with 

repeat testing of both groups over a 2-year period. Vision test results for the blast-exposed group 

were within or slightly lower (worse) than normal ranges and symptom scores did not differ 

between blast-exposed and control. A study of 21 participants in a 2-week New Zealand military 

breacher training course where blast exposures occurred one to 20 times per day on 5 of the 

training days observed changes in neurocognitive performance and self-reported symptom scores 

warranting further investigation.62 A report of neuropsychological and neurocognitive outcomes 

following a Canadian Explosives Forced Entry course (10 days of lectures and training on use of 

explosives to gain entry into building walls, doors, and windows) for police (4 instructors and 10 

students) found no significant changes from baseline to the end of the course.63

LIMITATIONS

The limitations of this review relate to little published information on blast injuries and 

variations in reporting across studies. There is no information on incidence and prevalence of 

blast injuries by blast mechanism (eg, primary, secondary, tertiary, quaternary, quinary) and 

limited reporting in studies comparing blast and non-blast TBI. For determination of incidence 

and prevalence, there are also limited published data on numbers of soldiers deployed that 

accurately take into account factors such as true deployment length, combat intensity, and type of 

unit.7 Clear and consistent definitions for injuries (eg, casualties, battle injuries, wounded in 

action, etc) and consistent standards for what to include in numerators and denominators when 

calculating incidence is necessary for accurate interpretation of combat trauma data.64 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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In the TBI studies, diagnoses and outcomes assessment were done at different time points 

following the blast and using different instruments, making comparisons across studies difficult. 

Reporting of symptoms may change over time and persistent or late-occurring symptoms may or 

may not be related to an earlier TBI.4 For example, a recent study of 119,353 active duty US 

service members who began their first deployment in 2011 and were followed for approximately 

4 years reported 11,498 first-time TBI diagnoses in the cohort including 2,525 prior to 

deployment, 3,086 during deployment, and 5,897 after deployment.65 Cause of injury data were 

not complete and were not fully reported. In addition, authors used varying definitions of 

blast/non-blast injury. It was unclear whether the increased rate of TBI diagnoses postdeployment was a result of late diagnoses of TBI that occurred during deployment, delayed 

diagnoses during a more complete evaluation of severe injuries obtained during deployment, or 

increased post-deployment injury, possibly due to increased risk-taking behaviors. 

Furthermore, confounding factors in studies of blast-exposed soldiers make it difficult to isolate 

the effects of the blast.63 In studies comparing individuals with blast and non-blast TBI, 

outcomes such as headache, sleep disturbance, memory difficulties, and depression may be 

attributed to factors other than blast exposure (eg, deployment status, chronic pain and other 

physical injuries, substance use disorders).4

APPLICABILITY OF FINDINGS TO THE VA POPULATION

Our review was limited to studies of combat injuries associated with OEF, OIF, and OND. The 

findings are highly applicable to military personnel and organizations that provide direct acute or 

chronic health care services including rehabilitation as well as employment to those either 

currently serving or of recent Veteran status. Additionally, an understanding of the incidence, 

prevalence, outcomes, and causal factors of blast and non-blast injuries may be used to help 

reduce these injuries in future combat operations. 

However, many studies reported findings from individuals presenting to medical facilities and 

undergoing treatment for a specific combat injury. Patient and injury characteristics and 

subsequent health outcomes from these selected patients may differ in unknown ways from the 

broader group of individuals who had combat injuries. We also have little information on very 

long-term effects (eg, cognitive function decline over decades). 

The Analysis of VA Health Care Utilization among Operation Enduring Freedom (OEF), 

Operation Iraqi Freedom (OIF), and Operation New Dawn (OND) Veterans (released June 2015) 

reports that 1,906,754 OEF/OIF/OND Veterans have become eligible for VA health care since 

fiscal year 2002 (beginning October 1, 2001) and approximately 2.7 million troops (as of 

December 31, 2014) have served or are serving in the 2 theaters of operation since the beginning 

of the conflicts in Iraq and Afghanistan 

(http://www.publichealth.va.gov/docs/epidemiology/healthcare-utilization-report-fy2015-

qtr1.pdf Accessed 10 August 2015). In 2007, the VA began a program of TBI screening and 

comprehensive. OEF/OIF/OND Veterans who present for care at a VA facility undergo a screen 

for TBI.66 One of the screening questions addresses exposure to physical trauma. Veterans who 

screen positive for TBI undergo a comprehensive evaluation. An analysis of data from October 

2007 to June 2010 found that 55% (30,267/55,070) of those evaluated for TBI after a positive 

screen were diagnosed with TBI. Of those, 36% had blast exposure and 44% had both blast and 

non-blast exposures.67
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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RESEARCH GAPS/FUTURE RESEARCH

In the Institute of Medicine’s “Gulf War and Health, Volume 9: Long-term Effects of Blast 

Exposures,” recommendations for future work highlighted the need to fill the gaps in the 

evidence base pertaining to the health effects of blast exposure and the need for greater emphasis 

on identifying and treating the complex injury patterns that often follow blast exposure. 

Collaborative efforts between the VA, DoD, and others were encouraged including the 

development of more complete registries with detailed information about the blast environment, 

information about both blast-injured and blast-exposed service members, and measurement of 

long-term health outcomes.68 

Accurately recording in a standardized fashion every injury to every individual who experiences 

a blast (including type of blast [eg, primary, secondary, etc], distance from the blast, etc), and 

then following those individuals to assess long-term outcomes, would be ideal insofar as 

possible within the combat environment. However, for those who have been determined to have 

received blast-related injuries, additional information on the circumstances surrounding the 

injury should include: type of blast, distance from the blast, history of blast exposure, injury 

severity, assigned and actual duties, and military member’s physical and psychosocial 

characteristics. Additional information gathered would be useful to evaluate methods to reduce 

combat-related blast injuries. Comparisons versus deployed controls may facilitate our 

understanding of the mechanisms and severity of blast-related injuries and the long-term health 

and social consequences of those injuries. This includes not only the treatments and health 

outcomes specific to the blast injury but also the long-term psychosocial, employment, and 

economic impact of blast injuries and the role and capacity needs for health care systems and the 

work force as these individuals reintegrate into the civilian society. Existing databases may 

already contain some of this information and future analyses should incorporate blast data where 

possible. 

CONCLUSIONS

The published literature provides limited information about the true incidence and

prevalence of blast-related injuries experienced by US military personnel and the

outcomes associated with blast versus non-blast TBI. We found no reports of incidence

and prevalence of blast injuries associated with different combat roles.

Few studies of incidence of blast-related injuries or outcomes associated with blast versus

non-blast TBI report important characteristics of a blast injury: type of blast, how far the

individual was from the blast, whether they experienced a blast wave, whether there was

loss of consciousness or altered consciousness, whether there was amnesia (and length of

time), and whether there was additional trauma.

Only 6 studies, 3 of which were derived from the same data set, provide information

about the incidence and prevalence of blast-related injuries in the deployed population at

risk.

Pain, vision loss, vestibular dysfunction, functional status, depression, sleep disturbance,

alcohol misuse, and post-concussive symptoms were similar in groups of patients with

blast and non-blast TBI. Findings were less consistent for PTSD, hearing loss, cognitive
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

48

function, and headache. Few studies reported mortality, burn outcomes, limb loss, or 

quality of life. 

Reporting studies were often small and involved highly selected patients and thus may 

not be fully representative of all individuals with blast or non-blast TBI. There are little 

data on very long-term outcomes that may be particularly relevant to assessment of 

cognitive function and quality of life. 

Blast and blast injuries (including TBI) are often defined differently. Therefore, the 

incidence, prevalence, and patient outcomes may vary across studies in part due to 

differences in how blast injury is categorized. 

To more adequately address questions about consequences of blast exposure, future 

research efforts should focus on comprehensive and consistent documentation at the time 

of and following blast exposure and more complete analyses of databases that may have 

already captured blast exposure information. 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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trauma: different entities. Int Tinnitus J. 2009;15(2):115-118.

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non-blast: mild traumatic brain injury in U.S. military service members. J Int Neuropsychol 

Soc. 2012;18(3):595-605.

38. Lew HL, Jerger JF, Guillory SB, Henry JA. Auditory dysfunction in traumatic brain injury. J 

Rehabil Res Dev. 2007;44(7):921-928.

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nonblast-related mild traumatic brain injuries in Afghanistan and Iraq war veterans. J Int 

Neuropsychol Soc. 2010;16(5):856-866.

40. Maguen S, Madden E, Lau KM, Seal K. The impact of head injury mechanism on mental 

health symptoms in veterans: do number and type of exposures matter? J Trauma Stress. 

2012;25(1):3-9.

41. Mendez MF, Owens EM, Jimenez EE, Peppers D, Licht EA. Changes in personality after 

mild traumatic brain injury from primary blast vs. blunt forces. Brain Injury. 2013;27(1):10-

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42. Mendez MF, Owens EM, Reza Berenji G, Peppers DC, Liang LJ, Licht EA. Mild traumatic 

brain injury from primary blast vs. blunt forces: post-concussion consequences and 

functional neuroimaging. NeuroRehabilitation. 2013;32(2):397-407.

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44. Nakase-Richardson R, McNamee S, Howe LL, et al. Descriptive characteristics and 

rehabilitation outcomes in active duty military personnel and veterans with disorders of 

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2013;94(10):1861-1869.

45. Oleksiak M, Smith BM, St Andre JR, Caughlan CM, Steiner M. Audiological issues and 

hearing loss among Veterans with mild traumatic brain injury. J Rehabil Res Dev. 

2012;49(7):995-1004.

46. Pogoda TK, Hendricks AM, Iverson KM, et al. Multisensory impairment reported by 

veterans with and without mild traumatic brain injury history. J Rehabil Res Dev. 

2012;49(7):971-984.

47. Reid MW, Miller KJ, Lange RT, et al. A multisite study of the relationships between blast 

exposures and symptom reporting in a post-deployment active duty military population with 

mild traumatic brain injury. J Neurotrauma. Dec 1 2014;31(23):1899-1906.

48. Sayer NA, Chiros CE, Sigford B, et al. Characteristics and rehabilitation outcomes among 

patients with blast and other injuries sustained during the Global War on Terror. Arch Phys

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U.S. military personnel medically evacuated from Iraq and Afghanistan with combat-related

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review of Operation Enduring Freedom and Iraqi Freedom. J Trauma Acute Care Surg. 

2012;73:S514-S519.

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of craniomaxillofacial injuries incurred during operations Enduring Freedom and Iraqi 

Freedom. J Trauma Acute Care Surg. 2012;73(6 Suppl 5):S453-458.

52. Blair JA, Patzkowski JC, Schoenfeld AJ, al. e. Spinal column injuries among Americans in 

the Global War on Terrorism. J Bone Joint Surg Am. 2012;94:e136(131-139).

53. Thach AB, Johnson AJ, Carroll RB, al. e. Severe eye injuries in the war in Iraq, 2003-2005. 

Ophthalmology. 2008;115:377-382.

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colorectal trauma: a review of 977 coalition casualties. J Trauma Acute Care Surg. 

2012;73:S503-S508.

55. Shah A, Syala M, Capra G, Fox D, Hoffer M. Otologic assessment of blast and non-blast 

injujry in returning Middle East-deployed service members. Laryngoscope. 2014;124:272-

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56. Fleming M, Waterman S, Dunne J, D'Alleyrand J-C, Andersen RC. Dismounted complex 

blast injuries; patterns of injuries and resource utilization associated with the multiple 

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57. Hoencamp R, Vermetten E, Tan EC, Putter H, Leenen LP, Hamming JF. Systematic review 

of the prevalence and characteristics of battle casualties from NATO coalition forces in Iraq 

and Afghanistan. Injury. 2014;45(7):1028-1034.
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58. Elder GA, Cristian A. Blast-related mild traumatic brain injury: mechanisms of injury and 

impact on clinical care. Mt Sinai J Med. 2009;76(111-118).

59. Surveillance snapshot: Responses to the traumatic brain injury (TBI) screening questions on 

the 2012 version of the post-deployment health assessment (DD Form 2796). MSMR. 

2015;22(2):12-13.

60. St. Onge P, McIlwain DS, Hill ME, Walilko TJ, Bardolf LB. Marine Corps breacher training 

study: auditory and vestibular findings. US Army Med Dep J. 2011:97-107.

61. Capo-Aponte JE, Jurek GM, Walsh DV, Temme LA, Ahroon WA, Riggs DW. Effects of 

repetitive low-level blast exposure on visual system and ocular structures. J Rehabil Res Dev. 

2015;52(3):273-290.

62. Tate CM, Wang KKW, Eonta S, et al. Serum brain biomarker level, neurocognitive 

performance, and self-reported symptoms changes in soldiers repeatedly exposed to lowlevel blast: a breacher pilot study. J Neurotrauma. 2013;30:1620-1630.

63. Baker AJ, Topolovec-Vranic J, Michalak A, et al. Controlled blast exposure during forced 

explosive entry training and mild traumatic brain injury. J Trauma. 2011;71:S472-S477.

64. Holcomb JB, Stansbury LG, Champion HR, Wade C, Bellamy RF. Understanding combat 

casualty care statistics. J Trauma. 2006;60(2):397-401.

65. Regasa LE, Thomas DM, Gill RS, Marion DW, Ivins BJ. Military Deployment May Increase 

the Risk for Traumatic Brain Injury Following Deployment. J Head Trauma Rehabil.

2016;31(1):E28-35.

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Brain Neurotrauma: Molecular, Neuropsychological, and Rehabilitation Aspects. Boca 

Raton (FL): CRC Press/Taylor & Francis; 2015.

67. Scholten JD, Sayer NA, Vanderploeg RD, Bidelspach DE, Cifu DX. Analysis of US 

Veterans Health Administration comprehensive evaluations for traumatic brain injury in 

Operation Enduring Freedom and Operation Iraqi Freedom Veterans. Brain Inj. 

2012;26(10):1177-1184.

68. Institute of Medicine. Gulf War and Health, Volume 9: Long-term Effects of Blast 

Exposures. Washington, DC: The National Academies Press; 2014.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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APPENDIX A. SEARCH STRATEGIES 

KEY QUESTIONS 1 AND 2 

1. (operation enduring freedom or operation iraqi freedom or operation new dawn).mp.

2. (OEF or OIF or OND).mp.

3. exp Afghan Campaign 2001-/ 

4. exp Iraq War, 2003-2011/

5. 1 or 2 or 3 or 4

6. (blast$ and injur$).mp.

7. blast$.mp.

8. ep.fs.

9. incidence.mp.

10. prevalence.mp.

11. 8 or 9 or 10

12. 6 or 7

13. 5 and 11 and 12

14. military personnel.mp. or exp Military Personnel/

15. 5 or 14

16. blast injuries.mp. or exp Blast Injuries/

17. 6 or 7 or 16

18. 11 and 15 and 17

19. limit 18 to (english language and yr = "2001 -Current")

KEY QUESTION 3

1. brain injury.mp. or exp Brain Injuries/

2. exp Wounds, Nonpenetrating/

3. exp Wounds, Penetrating/

4. (blast or (non-blast or nonblast)).mp.

5. (traumatic brain injur$ or tbi).mp.

6. brain.mp.

7. exp Afghan Campaign 2001-/ 

8. exp Iraq War, 2003-2011/

9. (operation enduring freedom or operation iraqi freedom or operation new dawn).mp.

10. (OEF or OIF or OND).mp.

11. 7 or 8 or 9 or 10

12. 2 or 3 or 4

13. 1 or 5 or 6

14. 11 and 12 and 13

15. (military or combat or deploy$).mp.

16. 12 and 13 and 15

17. 14 or 16

18. limit 17 to (english language and yr = "2001 -Current")

19. military personnel.mp. or exp Military Personnel/

20. (military or veteran$ or soldier$).mp.

21. 15 or 19 or 20

22. 12 and 13 and 21

23. 16 or 22

24. limit 23 to (english language and yr = "2001 -Current")
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

55

APPENDIX B. PEER REVIEWER COMMENTS AND RESPONSES

Reviewer Comment Response

Are the 

objectives, 

scope, and 

methods for this 

review clearly 

described?

Yes 

Yes 

Yes 

Yes 

Yes 

No - The questions were too broad. In light of the lack of detail in 

reporting, we should have picked one or two types of injury common to 

blast. In addition, failure to answer the first two questions indicates a 

problem with the process of reporting.

We sought input from Operational Partners and 

Technical Expert Panels to guide the report 

development.

Is there any 

indication of bias 

in our synthesis 

of the evidence?

No 

No 

No 

No 

No 

No 

Are there any 

published or 

unpublished

studies that we 

may have 

overlooked?

No 

Yes - Consider including the following article for DoD TBI 

incidence/denominator sample data: Regasa, et.al. (2015, JHTR 

ahead of pub) "Military Deployment May Increase the Risk for TBI 

Following Deployment". Posted under Reviewer attachments for your 

consideration.

We have included this article in the Discussion section. 

Although it includes a large sample, it is not truly an 

incidence report given that some service members were 

excluded. Furthermore, there was inadequate data for 

the authors to comment on causes of injury.

Yes - Noted within the comments but there are unpublished, classified 

studies that we do not mention and it appears that no attempts were 

made to obtain data from JTAPIC.

Classified studies would be out of scope. 

We looked at the military injury database sites for posted 

reports.

Yes - Not sure if these were reviewed, but there is limited mention of 

VA data related to the TBI screening and evaluation process. There 

are questions specific to blast in both the screen and evaluation 

template. Studies with this data may not have been strong enough to 

include, but it would appear to be an area for possible expanded use 

in the future. 

We have added information about the VA TBI screening 

and evaluation process including the findings of Scholten 

et al.(2012). We did not find other reports of findings 

related to the VA protocol.

We have noted in the Future Research section that 

additional analyses of existing databases are needed.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

56

Yes - The data from VA re incidence/prevalence for key questions 1 

and 2: Scholten JD,Sayer NA et al: Analysis of US Veterans Health 

Administration for Traumatic Brain Injury...Brain Injury ISSN: 0269 = 

9052; DePalma RG Combat TBI: History, Epidemiology, and Injury 

Modes. DePalma RG.In:Kobeissy FH, editor: Brain Neurotrauma: 

Molecular, Neuropsychological, and Rehabilitation Aspects. Boca 

Raton (FL): CRC Press/Taylor & Francis; 2015. Chapter 2. Frontiers in 

Neuroengineering

We have reviewed the suggested references and have 

included them in the Applicability section. We have noted 

that most studies do not include a denominator that 

allows determination of true incidence or prevalence.

Yes - MSMR was not cited, a major resource of traumatic injuries due 

to blast. VA TBI Screen and Comprehensive Eval publications were 

not cited.

We searched the contents of MSMR for relevant 

publications and have added the Surveillance Snapshot 

from the February 2015 edition. Other reports either did 

not distinguish blast-related injuries (combining gun and 

explosive events), included all service members (not 

limited to OEF/OIF/OND), or did not provide an 

appropriate denominator.

Additional 

suggestions or 

comments can 

be provided 

below. If 

applicable, 

please indicate 

the page and line 

numbers from 

the draft report.

Thank you for an excellent and very focused review. It is unfortunate 

that after so many years of research, we continue to find there is little 

known about a variety of TBI-related issues. The root cause of many 

of our lingering questions stems from our shortcomings in diagnostic 

accuracy, among other limitations of existing data. We have a growing 

expertise treating symptoms associated with TBI, but without objective 

diagnostic criteria and without adequately controlled, comparative 

studies the best outcomes may elude us. 

In addition to the DoDTR and MTR (which likely contain the best blast 

data), data from the Armed Forces Health Surveillance Center 

(AFHSC) may be the most comprehensive for (first) TBI incident 

reporting (see 2015 article attached). 

Editing comments:

1) Page 34 - Cognitive Function / Other, review of Clark 2009 was not 

easy to read/follow. The sentence seems broken.

2) Page 40 - vestibular EFFECTS (not affects) 

We have added information about limitations of the 

existing data in the Discussion section.

We have cited the Regassa 2015 reference. As noted 

above, we have checked military injury database sites 

for posted reports.

Editing:

1) we have revised this sentence

2) we have made the suggested change
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

57

p. 7, line 22 - citation to Cernak or Okie related to definition of injury 

would be best here

p. 11, line 15 - are we certain that there is no study related to 

amputation due to blast injury -is this included in extremity injury. I 

think amputation is considered differently than musculoskeletal injury

p. 14, line 33 - I would refer to this as musculoskeletal injury and again 

would clarify if this is extremity trauma vs. orthopedic injury 

(fracture/soft tissue)

p. 14, line 53 - I believe there are citations related to burn related to 

explosion

1: Escolas SM, Archuleta DJ, Orman JA, Chung KK, Renz EM. 

Postdischarge Cause-of-Death Analysis of Combat-Related Burn 

Patients. J Burn Care Res. 2015 Dec 1. [Epub ahead of print] PubMed 

PMID: 26629656.

2: Barillo DJ, Pozza M, Margaret-Brandt M. A literature review of the 

military uses of silver-nylon dressings with emphasis on wartime 

operations. Burns. 2014 Dec;40 Suppl 1:S24-9. doi: 

10.1016/j.burns.2014.09.017. Review. PubMed PMID: 25418434.

3: Valerio IL, Sabino J, Mundinger GS, Kumar A. From battleside to 

stateside: the reconstructive journey of our wounded warriors. Ann 

Plast Surg. 2014 May;72 Suppl 1:S38-45. doi: 

10.1097/SAP.0000000000000168. PubMed PMID: 24740023.

4: Jeevaratnam JA, Pandya AN. One year of burns at a role 3 Medical 

Treatment Facility in Afghanistan. J R Army Med Corps. 2014 

Mar;160(1):22-6. doi: 10.1136/jramc-2013-000100. Epub 2013 Jun 7. 

PubMed PMID: 24109100.

5: Feldt BA, Salinas NL, Rasmussen TE, Brennan J. The joint facial 

and invasive neck trauma (J-FAINT) project, Iraq and Afghanistan 

2003-2011. Otolaryngol Head Neck Surg. 2013 Mar;148(3):403-8. doi: 

10.1177/0194599812472874. Epub 2013 Jan 11. PubMed PMID: 

23314163.

6: Chan RK, Siller-Jackson A, Verrett AJ, Wu J, Hale RG. Ten years of 

war: a characterization of craniomaxillofacial injuries incurred during 

operations Enduring Freedom and Iraqi Freedom. J Trauma Acute 

Care Surg. 2012 Dec;73(6 Suppl 5):S453-8. doi: 

10.1097/TA.0b013e3182754868. PubMed PMID: 23192069.

7: Mora AG, Ritenour AE, Wade CE, Holcomb JB, Blackbourne LH, 

Gaylord KM. Posttraumatic stress disorder in combat casualties with 

burns sustaining primary blast and concussive injuries. J Trauma. 

2009 Apr;66(4 Suppl):S178-85. doi: 10.1097/TA.0b013e31819ce2d6. 

PubMed PMID: 19359963.

8: Gaylord KM, Cooper DB, Mercado JM, Kennedy JE, Yoder LH, 

Holcomb JB. Incidence of posttraumatic stress disorder and mild 

p7/22. We have added the Cernak reference to the full 

report (we did not include references in the Executive 

Summary). 

p11/15. The report of musculoskeletal injuries included 

amputations. We have noted this in the Executive 

Summary and full report and have added data to the 

Appendix tables.

p14/33. We have made this change and clarified the type 

of injury.

p14/53. We have reviewed each of the suggested 

references. Two were already included (Chan, Mora)

although Chan has now been removed because the 

denominator was not number deployed. We added a 

burn outcome reported by Mora to the outcomes for 

KQ3. None of the other references provided outcomes 

pertaining to the key questions.

p17/26. We have added the Cernak reference.

p26/14. The study this comment refers to has been 

deleted because it did not provide a suitable 

denominator.

p26/23. The study this comment refers to has also been 

deleted because it did not provide a suitable 

denominator.

p28/30. The inconsistency and spacing issues noted 

have been eliminated with the switch to superscript 

reference citations in the final version of the report.

p35/8. We have made this correction.

p45/35. We have made this change and clarified the type 

of injury included.

p46/6. We have made this change.

p46/50. We included only published data. As noted 

above, we looked at the military injury database sites for 

posted reports.

p47//21. We have added “published” to this sentence.

p47/55. We have revised this sentence.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

58

traumatic brain injury in burned service members: preliminary report. J 

Trauma. 2008 Feb;64(2 Suppl):S200-5; discussion S205-6. doi: 

10.1097/TA.0b013e318160ba42. PubMed PMID: 18376167.

p. 17, line 26 - again would reference Okie or Cernak

p. 26, line 14 - Did they include deployed population at time as the 

denominator? Should that be reported for consistency

p. 26, line 23 - suggest overall number be reported

p. 28, line 30 - this happens multiple times in the document, after this 

point, the period and the parentheses seem misaligned and are done 

inconsistently - some with period before, some after; other formatting 

problems with spacing should also be checked, noted this throughout 

the document.

p. 35, line 8 - s missing from patients

p. 45, line 35 - usually referred to as musculoskeletal injury and 

unclear if this includes SCI

p. 46, line 6 - change contraction don't to do not

p. 46, line 50 - was any attempt made to request data or technical 

reports from JTAPIC or DVBIC for unpublished data? 

http://jtapic.amedd.army.mil/getStarted.php

p. 47, line 21 - I think the caveat here is related to what is available in 

the published literature. There are unpublished data on the classified 

side that we know exist but to which we do not have access.

p. 47, line 55 - this sentence is awkward and I cannot rewrite because 

I cannot understand what is meant by it.

Applicability of Report page9 lines 9-18 references the 1,906 754 

OEF/OIF/OND veterans becoming eligible for VA Care. It is known 

that ~55% reported for VA care. All those screened for TBI; the 

numbers reporting, screened and completing TBI evaluation are also 

known. Currently these approach 80-90,000; with additional arriving 

with DOD diagnosed TBI 125-126,000(Bidelspach/Cifu). This is a 

partial denominator which needs to be taken into consideration, 

recognizing that we cannot extrapolate to those not reporting and 

seen.

There were many reports of “proportional” outcomes –

the fraction of an exposed group (ie, those injured in 

combat)(Holcomb 2006) but we have defined incidence 

based on number deployed and included only studies 

that report incidence or prevalence for the deployed 

population. We have included information about the VA 

TBI evaluation program in the Applicability section of the 

report.
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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APPENDIX C. EVIDENCE TABLES 

Table 1. Study Characteristics – Key Questions 1 and 2 

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics

Database

Clinical 

Cohort

Belmont, 20106

Funding Source: No 

external funding 

received

Joint Theater 

Trauma Registry

Electronic 

medical records

4,122 deployed 

during study 

period

2007

Iraq (surge)

US Army Brigade Combat Team (BCT)

ICD-9 Codes 800-960

Branch of service: 100% Army

Rank: 

E1-E4 (junior enlisted): 50%

E5-E9 (senior enlisted): 40%

O1-O3/WO1-WO5 (junior officers and warrant officers): 8%

O4-O6 (senior officers): 1%

Duty/description: NR

Blast exposure history: NR

Time since exposure: N/A

Duration of deployment: 15 months

Rural vs urban residence: NR

Gender (% male): 92

Mean age (years): 27

Belmont, 20128

Funding Source: 

None reported

Joint Theater 

Trauma Registry

1,992,232 

deployed during 

study period

2005-2009

Iraq and Afghanistan

ICD-9 Codes 800-960

Did not include killed in action (KIA) 

Combat Casualty Cohort

Branch of service: 78% Army, 2% Navy, 1% Air Force, 19% Marines

Rank:

E1-E4 (junior-enlisted): 59%

E5-E9 (senior-enlisted): 34% 

O1-O3 (junior officers) and all warrant officers: 6% 

O4-O10 (senior officers): 1% 

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence: NR

Gender (% male): 99 

Mean age (years): 26

Belmont, 20137

Funding Source: 

None received

(Additional analysis of 

cohort described in 

Belmont 2012)

Joint Theater 

Trauma Registry

1,992,232 

deployed during 

study period

2005-2009

Iraq and Afghanistan

Musculoskeletal combat casualty: 

wound to upper or lower extremities, 

spine, or pelvis

Musculoskeletal Combat Casualty Cohort

Branch of service: 78% Army, 2% Navy, 1% Airforce, 19% Marines

Rank: 59% Junior Enlisted, 34% Senior Enlisted, 6% Junior Officer, 1% Senior 

Officer, <1% unknown

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence: NR

Gender (% male): 99 

Mean age (years): 26
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics

Database

Clinical 

Cohort

Schoenfeld, 20139

Funding Source: 

None received

(Additional analysis of 

cohort described in 

Belmont 2012)

Department of 

Defense Trauma 

Registrya 

1,992,236 

person-years of 

exposure during 

study period

2005-2009

Iraq and Afghanistan

Spinal injury identified from manual 

search of records from 7,877 casualties; 

included spine fractures, spinal 

dislocations, disk displacements, nerve 

root injuries, and spinal cord injuries

(Additional analysis of data reported in 

Belmont 2012)

Spinal Injury Cohort

Branch of service: 81% Army, 2% Navy, 1% Airforce, 16% Marines

Rank: 57% Junior Enlisted, 36% Senior Enlisted, 7% Officers, 1% unknown

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence: NR

Gender (% male): 99 

Mean age (years): 27

Freedman, 201410

Funding Source: 

None reported

Joint Theater 

Trauma Registry

Landstuhl 

Regional 

Medical Center

(spinal surgery 

and radiology 

reports)

2007-2010 (test cohort 2009-2010, 

historical controls 2007-2008 and 2008-

2009)

Iraq and Afghanistan

Thoracolumbar combat burst fracture

defined as improvised explosive device 

attack against an armored vehicle

Combat Casualty Cohort

Branch of service: Army > Marines > Air Force

Rank: 59% from lowest four enlisted ranks

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence: NR

Gender (% male): 97

Mean age (years): 30

Goldberg, 201411

Funding Source: 

Congressional 

Budget Office

Department of 

Defense tabular 

reports

OEF, OIF, OND from beginning of 

conflicts to April 4, 2011

Major amputation defined as loss of limb 

at or proximal to wrist or ankle

Amputation Cohort

n = 1,186 service members with at least 1 major amputation (809 in Iraq, 377 in 

Afghanistan)

Branch of service: NR

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence: NR

Gender (% male): NR

Mean age (years): NR a Joint Theater Trauma Registry renamed Department of Defense Trauma Registry in 2012
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

61

Table 2. Incidence and Prevalence Outcomes

Author, Year Blast Injury Incidence Other Incidence Findings Blast Injury Prevalence Other Prevalence Findings

Belmont, 20106

2007: 8% (341 explosion 

casualties/4,122 deployed

or 

83 explosion 

casualties/1,000 deployed)

a

KIA: 0.6% (25/4,122)

DOW: 0.05% (2/4,122) 

MEDEVAC: 1.6% (68/4,122) 

RTD: 6.0% (246/4,122) 

Blast Characteristics: NR

Injury Site (number of body 

regions injured by 

explosion/total number of 

body regions injured): 

Head/Neck: 49.3%

Thorax: 2.9%

Abdomen: 4.4% 

Extremity: 31.2%

Injury Outcome: 97.8% of 

concussions were 

explosion related

Belmont, 20128

WIA-DOW 

2005: 0.45% (1,476 explosion 

casualties/ 

331,593 deployed or 

4.5/1,000) 

2006: 0.35% (1,347/383,896

or 3.5/1,000) 

2007: 0.40% (1,549/390,943

or 4.0/1,000) 

2008: 0.17% (736/438,220 or 

1.7/1,000) 

2009: 0.17% (754/447,580 or

1.7/1,000)

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR

5 years (2005-2009)

WIA-DOW: 

0.29% (5,862 explosion 

casualties/ 

1,992,232 deployed)

74.4% (5,862/7,877) WIA-DOW 

casualties were explosion 

related

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year Blast Injury Incidence Other Incidence Findings Blast Injury Prevalence Other Prevalence Findings

Belmont, 20137

(Additional analysis of 

cohort described in

Belmont 2012)

WIA-DOW 

2005: 0.35% (1,177 

explosion-related 

musculoskeletal 

casualties/331,593 

deployed or 3.5/1,000) 

2006: 0.27% (1,048/383,896

or 2.7/1,000) 

2007: 0.31% (1,205/390,943

or 3.1/1,000) 

2008: 0.13% 

(563/438,220 or 1.3/1000) 

2009: 0.13% (570/447,580 or 

1.3/1,000) 

Blast Characteristics: NR

Injury Site NR

Injury Outcome: NR

Musculoskeletal Injury (2005-

2009) WIA-DOW:

0.23% (4,563 explosion-related 

musculoskeletal 

casualties/1,992,232 

deployed) 

82% (14,158/17,177) of 

musculoskeletal wounds were 

explosion related

Blast Characteristics: NR

Blast-related Injury Site:

Axial skeleton fracture

0.42/1,000 deployed per year

(841/1,142 fractures [74%]) 

Upper extremity fracture

0.96/1,000 deployed per year

(1,917/2,470 fractures [78%])

Lower extremity fracture

1.32/1,000 deployed per year

(2,662/3,182 fractures [84%])

Amputation

0.49/1,000 deployed per year

(976/1,039 amputations [94%]) 

Neurological injury

0.30/1,000 deployed per year

(596/927 injuries [64%]; includes 

45/96 spinal cord injuries [47%])

Joint dislocation

0.15/1,000 deployed per year

(304/361 dislocations [84%]) 

Soft tissue injury 

3.42/1,000 deployed per year

(6,862/8,056 injuries [85%]) 

Injury Outcome: NR

Schoenfeld, 20139

(Additional analysis of 

cohort described in 

Belmont 2012)

Spinal Injury

2005: 0.04% (134 explosionrelated spinal 

injuries/331,593 deployed

or 0.40/1,000) 

2006: 0.04% (144/383,900 or 

0.38/1,000) 

2007: 0.04% (152/390,943 or 

0.38/1,000) 

2008: 0.02% (78/438,220 or 

0.18/1,000) 

2009: 0.03% (137/447,580 or 

0.31/1,000)

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR

Spinal Injury (2005-2009)

0.03% (650 with explosionrelated spinal 

injuries/1,992,236 deployed)

or 3.3/10,000 

75% (650/872) of individuals 

with spinal injuries had 

explosion-related injuries

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year Blast Injury Incidence Other Incidence Findings Blast Injury Prevalence Other Prevalence Findings

Freedman, 201410

Thoracolumbar burst fracture 

incidence per 10,000 

soldier-years

2007-2008: 0.45 (9 events [4 

IED related]) 

2008-2009: 0.60 (11 events [6 

IED related]) 

2009-2010: 2.08 (38 events

[32 IED related])

b

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR

Thoracolumbar burst fractures 

per 10,000 soldier-years (2007-

2010)

Combat mechanism of injury

(IED): 2.02 (38 events)

Other mechanisms of injury: 

1.06 (20 events)

Blast Characteristics: NR

Blast Injury Site: All thoracolumbar 

Injury Outcome: NR

Goldberg, 201511

Major IED-related amputations 

(2001-April 2011):

OIF, OND (Iraq): 38.3/100,000 

troop years

OEF (Afghanistan): 

87.8/100,000 troop years.

Blast Characteristics: NR

Injury Site: NR

Injury Outcome: NR

a Some soldiers had >1 casualty but exact number of soldiers with explosion and non-explosion casualties not reported b In the 2009-2010 cohort, there were 38 events among Service Members; 28 of those events were IED-related; 4 events were in non-US Service Members

DOW = died of wounds; WIA = wounded in action; KIA = killed in action; MEDEVAC = medically evacuated; RTD = returned to duty; IED = improvised explosive device; NR

= not reported
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Table 3. Study Characteristics – Key Question 3

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Akin, 201115

Funding Source: VA

Inclusion: Consecutive 

Veterans with history of blast 

and/or mTBI; referred to VAMC 

Vestibular/Balance Laboratory 

for complaints of dizziness 

and/or imbalance

N = 18 with mTBI (n = 9 blast, n = 9 

non-blast)

Age (years): 37 (total sample); range 

23-76; 25 (81%) Veterans from 

Iraq/Afghanistan wars

Gender: NR

Cohort or service year(s): NR

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

Vestibular and balance 

assessment

a. Horizontal semicircular canal 

function (rotary chair 

videonystagmography)

b. Otolith function (cVEMPs and 

SVV tests during unilateral 

centrifugation)

c. Tests for BPPV (Dix-Hallpike, 

roll test)

d. Central vestibular function 

(ocular motor and fixation tests)

d. Postural stability (SOT)

e. Self-perceived handicap 

(Dizziness Handicap Inventory)

Belanger, 200926

Funding Source: 

resources and use of 

facilities at 4 VA 

Medical Centers and 

the Mid-Atlantic 

MIRECC

Inclusion: Consecutively 

assessed individuals from 

Tampa VAMC and selected 

research volunteers from 3 

VAMCs in the Mid-Atlantic 

MIRECC

Exclusion: Suspected of poor 

effort and malingering based on 

clinical presentation and/or 

failed certain measured of 

symptom validity; other known 

neurological disorders (apart 

from TBI), brain injury due to 

gunshot

N = 102 (n = 61 blast, n = 41 nonblast)

Age (years) at evaluation: 

-Blast: 29

-Non-blast: 28 (P>.59) 

Gender (% male): 96

Cohort or service years(s): NR (Iraq 

and Afghanistan)

Rank: NR

Duty/description: active duty: 67%

Blast exposure history: NR

Time since exposure: 443 days 

(blast); 954 days (non-blast); P>.13

Duration of deployment: NR

Rural or urban residence: NR

Trail Making Test

Digit Symbol-Coding subset of 

Wechsler Adult Intelligence Scale3rd edition (WAIS-III)

Brief Visuospatial Memory TestRevised (BVMT-R)

California Verbal Learning Test-II 

(CVLT-II)

Post-traumatic stress disorder 

checklist (PCL) (self-report)
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Belanger, 201127

Funding Source: VHA, 

DVBIC

Inclusion: Patient from Tampa 

or Bay Pines VAMC or 

WRAMC; reported history of 

mTBI based on diagnostic 

interview and available records; 

TBI diagnosis based on DoD 

criteria (external force acting on 

individual resulting in alteration 

or loss of consciousness); mild 

TBI was loss of consciousness 

< 30 minutes and posttraumatic amnesia < 24 hours; 

completed measures used in 

study; consented to participate

N = 390 (n = 298 blast, n = 92 nonblast)

Tampa VAMC: 40; Bay Pines VAMC: 

25; WRAMC: 325

Age (years): 

-Blast: 28

-Non-blast: 30 (P = .08)

Gender (% male): 94%

Cohort years: NR

Rank: NR

Duty/description: 87% active duty

Time since exposure (mean):

-Blast: 11.9 months

-Non-blast: 25.9 months (P = .002) 

Duration of deployment: NR

Rural or urban residence: NR

PTSD Checklist (PCL); self-report; 

17 items (rated 1-5 with 1 = not at 

all and 5 = extremely)

Neurobehavioral Symptom 

Inventory (NSI); self-report; postconcussion symptoms; 22 items 

(rated 0-4 with 0 = none and 4 = 

very severe)

Brahm, 200928

Funding Source: VA 

Quality and 

Enhancement 

Research Initiative 

(QUERI) grant

Inclusion: Consecutive 

polytrauma inpatients (PRC) or 

outpatients (PNS); combatinjured

PRC: 84% with moderate to 

severe TBI, polytrauma; 

typically acute or sub-acute 

stage of rehabilitation

PNS: mTBI, postacute

Inpatients N = 68 (n = 57 blast, n = 

11 non-blast)

Age (years):

-Blast: 28.6

-Non-blast: 28.8

Gender (% male): 96% overall

Cohort years: 2004-2006

Outpatients N = 124 (n = 112 blast, n

= 12 non-blast)

Age (years):

-Blast: 29.7

-Non-blast: 37.9 (P<.025)

Gender (% male): 96 overall

Cohort years: 2006-2007

Both Groups: 

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural vs urban residence. NR

Visual impairment: loss of visual 

acuity (Feinbloom chart or other 

tests used for verbally nonresponsive patients) or visual field 

(Goldmann visual fields if patient 

capable)

Ocular injuries

Subjective visual complaint
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Clark, 200929

Funding Source: 

Department of 

Veterans Affairs 

Rehabilitation 

Research and 

Development grant

Inclusion: Consecutively 

admitted to TPRC; active duty 

and Veterans; patient’s medical 

records had self-reported 

admission pain scores

Exclusion: Severe brain injuries 

and associated significant 

communications deficits

TBI: 83% of blast group, 79% 

of non-blast group; more 

penetrating TBI in blast group, 

more closed TBI in non-blast 

group

N = 128 (n = 51 combat blast; n = 34 

combat non-blast)*

Age (years):

-Blast: 28

-Non-blast: 27

Gender (% male)

-Blast: 96

-Non-blast: 94

Cohort years: 2003-2006

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

*NOTE: n = 43 non-combat not 

included in analysis

Functional Independence Measure 

(FIM) – 18 items

a) ability for independent function 

in daily activities

b) cognitive function

-Rancho Los Amigos Scale 

(Rancho) – behavioral 

characteristics and cognitive 

deficits associated with recovery 

from brain injury

-Pain Numeric Rating Scale (NRS) 

– pain intensity in those capable of 

self-report; extracted if Rancho ≥ 

VI

-Number of pain sites

-Number of psychiatric diagnoses 

Cockerham, 201330

Funding Source:

Veterans 

Administration Merit 

Review Award

Inclusion: Diagnosis of TBI; 

ability to undergo clinical 

examination and psychometric 

testing

Exclusion: Eyes with openglobe injury; using topical 

ocular medications

N = 53 (n = 44 blast, n = 9 non-blast)

Age (years): 26

Gender (% male): 100

Cohort years: NR

Rank: NR

Duty/description: 100% Veterans

Blast exposure history:

Time since exposure (median): 6 

months (range 1-60)

Duration of deployment: NR

Rural or urban residence: NR

Ocular Surface Disease Index 

(OSDI) – interview by research 

team member to assess dry eye 

disease (DED) symptoms; 12 

items scored 0 (none of the time) 

to 4 (all of the time); higher scores

= greater disability

Collen, 201231

Funding Source: No 

funding received

Inclusion: Consecutive soldiers 

with combat-related TBI (85% 

mTBI, 9% moderate, 6% 

severe); receiving care at 

WRAMC; age ≥ 18y; sustained 

non-penetrating TBI

Exclusion: sleep disorders 

diagnosed prior to injury

N = 116 (n = 82 blast, n = 34 blunt)

Age (years): 

-Blast: 30

-Non-blast: 35 (P = .01)

Gender (% male): 97

Cohort years: 2005-2010

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: 16 months

Duration of deployment: NR

Rural vs urban residence. NR

Epworth Sleepiness Scale (ESS): 

subjective assessment of daytime 

somnolence

Polysomnography: to detect 

insomnia and obstructive sleep 

apnea syndrome (OSAS); 

completed in 79% of patients
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Cooper, 201232

Funding Source: None 

reported

Inclusion: Consecutive 

admissions of OEF/OIF service 

members referred to TBI clinic 

at BAMC for 

neuropsychological testing Jan 

2008-Jan 2010; at least 18 

years old; fluent English; 

sustained injury while on active 

duty military service

Exclusion: no mTBI; major 

body burns and/or traumatic 

amputations affecting 

administration of 

neurocognitive measures; fell 

below empirically derived cut 

scores for suboptimal effort o 

psychometric testing; missing 

variables on key measures of 

interest

N = 60 (n = 32 blast, n = 28 nonblast)

Age (years): 

-Blast: 29.5

-Non-blast: 29.4 (P = .97)

Gender (%male): 

-Blast: 100

-Non-blast: 79% (P = .006)

Cohort years: 2008-2010

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: 

-Blast: 192 days

-Non-blast: 149 days

Duration of deployment: NR

Rural or urban residence: NR

Repeatable Battery for the

Assessment of 

Neuropsychological Status 

(RBANS) – cognitive functioning

Headache Impact Test (HIT-6) – 

headache severity and impact on 

daily function

Post-Traumatic Checklist-Military 

version (PCL-M) – self-rated

DuBose, 201113

Funding Source: None 

reported

Joint Theater 

Trauma 

Registry

Inclusion: 18 to 55 years old; 

sustained isolated TBI

N = 604 (n = 374 blast, n = 118 

gunshot, n = 112 blunt)

Age (years):

-Blast: 25.5

-Gunshot: 25.1

-Blunt: 27.1 (P = .04)

Gender (% male):

-Blast: 98.4

-Gunshot: 100

-Blunt: 94.6 (P = .01)

Cohort years: 2003-2007

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

Mortality
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Fortier, 201433

Funding Source: 

Translational Research 

Center for TBI and 

Stress Disorders, a VA 

Rehabilitation 

Research and 

Development (RR&D) 

Traumatic Brain Injury 

Center of Excellence

Inclusion: Consecutive 

deployed Veterans of OEF/OIF; 

enrolled in VA RR&Dsupported TBI Center of 

Excellence

Exclusion: History of seizures; 

prior serious medical illness; 

current active suicidal and/or 

homicidal ideation, intent, or 

plan; bipolar disorder, 

schizophrenia, or other 

psychotic disorder; cognitive 

disorder not due to TBI

NOTE: total sample of 131 

enrolled (56 with military TBI)

N = 56 (n = 26 blast, n = 30 nonblast)

Age (years): 34 (total sample)

Gender (% male): 86 (total sample)

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history (for 101/131 

with blast exposure within 100 

meters: mean blasts/person = 14, 

median = 2 

Time since exposure (mean): 31 

months (range 1-99) since last 

deployment (total sample)

Duration of deployment (mean): 13 

months (range 3-38) (total sample)

Rural vs urban residence. NR

Boston Assessment of Traumatic 

Brain Injury-Lifetime (BAT-L): 

questionnaire for preliminary 

screen administered as a selfreport questionnaire; captures 

number of exposures to blasts 

within 100 meters and number of 

TBIs due to blast, TBIs and their 

severity, and neurobehavioral 

symptoms (occurrence, timing of 

onset, and duration)

French, 201425

Funding Source: No 

funding received

Inclusion: US male Service 

members who sustained closed 

mTBI and were evaluated at 

WRAMC or SAMMC after 

injuries sustained during 

OEF/OIF (typically with other 

injuries); deployed ≤3 times; 

completed NSI, PCL-C, and 

Abbreviated Injury Scale (AIS); 

divided into 4 groups based on 

injury severity based in Injury 

Severity Score (ISS)

Exclusion: no additional criteria 

reported 

N = 579 (n = 73 minor injury, 278 

moderate, 148 serious, 80 

severe/critical); 82% injured as a 

result of blast exposure

Age (years): 27 

Gender (% male): 100

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure (mean): 12 

months or less (mean 73 days)

Duration of deployment (mean): NR

Rural vs urban residence. NR

-Neurobehavioral Symptom 

Inventory (NSI): 22 items, 

presence/severity of each 

symptom rated 0 (none) to 4 (very 

severe); total 0 (no symptoms) to 

88 (all symptoms at very severe 

level); 3 cluster scores 

(somatic/sensory, cognitive, 

affective)

-PCL-C: 17 items; self-reported 

PTSD symptoms; range 17 (not at 

all) to 85 (all symptoms at extreme 

level); 3 cluster scores (reexperiencing, avoidance, hyperarousal)

-ISS: based on AIS for 3 most 

severely injured body region (brain 

excluded for this study)
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Goodrich, 2013

Goodrich, 201434,35

Funding Source: 

Veterans Affairs Quality 

Enhancement 

Research Initiative 

(QUERI) grant

Inclusion: Admitted to VA PRC; 

documented eye exams with 

optometry; history of TBI

Exclusion: None reported

NOTES: 

a. many of the 50 non-blast 

TBIs occurred in non-combat 

settings

b. mTBI:

-Blast: 53% (26/49)

-Non-blast: 2% (1/49) (P = 

.0001)

c. 16 in blast group had 

documented secondary or 

tertiary trauma (non-primary 

injuries may not have been 

documented in remaining 

patients) 

N = 100 (n = 50 blast, n = 50 nonblast)

Age (years):

-Blast: 29

-Non-blast: 29

Gender (% male)

-Blast: 94%

-Non-blast: 96%

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history: 

-32% (16/50) of blast group had 

documented secondary or tertiary 

trauma

-32% (16/50) had >1 exposure

Time since exposure (mean): 

-Blast: 1 year (range 0.03-4.79)

-Non-blast: 0.32 years (range 0.02-

3.13)

Duration of deployment: NR

Rural or urban residence: NR

Subjective and objective ocular 

and vision data from eye 

examinations nearest in date to 

injury date

Self-reported vision complaints

Visual acuity

Reading ability

Ocular injuries

Hoffer, 200936

Funding Source: None 

reported

Inclusion: war-injured with 

diagnosis of or significant risk 

factors for mTBI; presented 

over 9 month period

VOR study: N = 55 (n = 21 blast, n = 

34 blunt)

Age (years): 26

Gender (% male): 100

VSR study: N = 72 (n = 39 blast, n = 

32 blunt)

Age (years): 24

Gender (% male): 96 

Both studies:

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

VOR study: Gain, phase and 

symmetry of sinusoidal harmonic 

acceleration testing (rotational 

chair)

VSR study: 

a. Sensory organization test (SOT)

b. Motor control test (latency 

times)
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Kennedy, 201016

Funding Source: US 

Army Medical 

Research and Materiel 

Command 

Inclusion: outpatients at 

SAMMC; screened and 

identified with mTBI due to 

blast or other mechanism while 

deployed; consented to allow 

information to be used for 

research

Exclusion: incomplete data on 

Posttraumatic Stress Disorder 

Checklist-Civilian version (PCLC); more severe TBI; no clear 

date of injury

NOTE: Blast group included 

significantly more Army soldiers 

(described as “more likely to 

engage in activities involving 

high risk of exposure to 

explosive munitions”)

N = 724 (n = 586 blast, n = 138 nonblast)

Age (years):

-Blast: 27.4

-Non-blast: 30.0 (P = .001)

Gender (% male)

-Blast: 98

-Non-blast: 92 (P = .001)

Cohort years: 2005-2009

Rank: 

-Blast: 95% enlisted, 5% officer

-Non-blast: 92% enlisted, 8% officer 

(P = .16 for blast vs non-blast)

Duty/description: NR (See NOTE)

Blast exposure history: NR

Time since exposure (mean): 31 

weeks (range 2 days to 5.4 years); P

= .43 (blast vs non-blast)

Duration of deployment: NR

Rural or urban residence: NR

PCL-C: 17- items measuring 

severity of PTSD symptoms; 

PTSD = score>50
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Kontos, 201322

Funding Source: US 

Special Operations 

Command Biomedical 

Initiatives Steering 

Committee

Inclusion: US Army Special 

Operations Command 

(USASOC) personnel 

completing web-based 

standardized baseline 

evaluations for mTBI 

symptoms, PTSD symptoms, 

and neurocognitive 

performance; at least 1 

diagnosis of mTBI; deployed 

and non-deployed settings

Exclusion: history of diagnosed 

moderate to severe TBI, brain 

surgery, major psychiatric 

disorder or neurologic disorder; 

neurocognitive assessment 

deemed invalid 

N = 2,813 (n = 861 blast, n = 1,700 

blunt, n = 252 blast-blunt 

combination)

Age (years): 29.5 

Gender (% male): 96

Cohort years: 2009-2011

Rank: NR

Duty/description: NR*

Blast exposure history: 1,113 with 

blast or combination (764 [69%] 1 

blast, 181 [16%] 2 blasts, 168 [15%] 

≥3 blasts)

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

*USASOC includes “Special Forces, 

Army Rangers, and other 

unconventional units involved in highrisk training, multifaceted global 

operations, and challenging combat 

missions”

Immediate Post-Concussion 

Assessment Cognitive Test 

(ImPACT) – military version: 

neurocognitive performance; 4 

composite scores 

Post-Concussion Symptom Scale 

(PCSS): 22 self-reported 

symptoms rated from 0 (none) to 6 

(severe)

PTSD Check List (PCL):17 items, 

how much each item bothered 

them for past month; 0 (not at all) 

to 5 (extremely)
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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Lange, 201237

Funding Source: No 

financial support 

received for completion 

of manuscript

Inclusion: sustained 

deployment related closed 

mTBI and evaluated at 

WRAMC following medical 

evacuation from OEF/OIF 

combat theater; completed core 

neuropsychological test battery; 

adequate effort on Word 

Memory Test; valid clinical 

profile on Personality 

Assessment Inventory; able to 

classify severity of injury as 

mild; assessed by TBI Service 

within 14 months of injury; male

NOTES: 

a. most patients evacuated for 

limb loss or systemic injuries

b. selected from sample of 662 

evaluated at WRAMC

N = 56 (n = 35 blast plus, n = 21 nonblast)

Age (years):

-Blast: 32.7

-Non-blast: 31.4 (P = .58)

Gender (% male): 100

Cohort years: 2002-2009

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure (mean): 

-Blast: 4.5 months

-Non-blast: 4.3 months (P = .83) 

Duration of deployment (mean): NR

Rural or urban residence: NR

Personality Assessment Inventory 

(PAI): T-score ≥ 60 = mild or 

higher, ≥ 70 = moderate or higher

Neurocognitive measures:

a. Trail Making Test (TMT)

b. California Verbal Learning Test 

2nd ed (CVLT-II)

c. Conner’s Continuous 

Performance Test-2nd ed (CPT-II)

d. Subsets from Wechsler Adult 

Intelligence Scale-3rd ed

e. Wechsler Test of Adult Reading

f. Word Memory Test (WMT)

Lew, 201114

Funding Source: VA 

Office of Research and 

Development, Health 

Services Research and 

Development Service

DoD 

Defense 

Management 

Data Center

Inclusion: medical records with 

information on demographics 

and results of comprehensive 

TBI evaluations performed in 

Veterans Health Administration

Exclusion: test cases; duplicate 

TBI evaluations; cases 

involving inconsistent 

responses regarding blast 

exposure; reported sustaining 

TBI at time other than 

deployment

N = 12,521 deployment related TBI 

(n = 10,431 blast, n = 2,090 nonblast)

(85% mTBI)

Age (years): 31.3

Gender (% male): 93.9

Cohort years: 2007-2009

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure (mean): NR

Duration of deployment (mean): NR 

(median number of deployments = 

1.0 [range 1-19]; median years of 

service = 4.0 [range 0-36])

Rural or urban residence: NR

Neurobehavioral Symptom 

Inventory (NSI-22): 22 items, selfreport extent to which cognitive, 

affective, somatic, or sensory 

symptoms have impacted them in 

past 30 days
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Lew, 200738

Funding Source: 

Unfunded at time of 

manuscript publication

Inclusion: new admissions to 

inpatient rehabilitation unit of a 

VAMC; TBI

Exclusion: none reported 

NOTE: blast vs non-blast 

analysis only includes patients 

admitted 2003-2006 (no blastrelated TBI in patients earlier)

N = 150 (n = 42 blast, n = 108 nonblast)

Age (years): 31.6

Gender (% male): 93

Cohort years: 2003-2006

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure (mean): NR

Duration of deployment (mean): NR 

Rural or urban residence: NR

Hearing loss

Tinnitus

Lippa, 201039

Funding Source: 

Supported in part by a 

Department of VA 

Center of Excellence 

Grant

Inclusion: Referred for TBI 

screening by nationwide VA 

process (ie, Veteran endorses 

each item):

1) Injury during deployment 

2) Injury resulted in any of the 

following: dazed, confused, 

memory problems, losing

consciousness, head injury, 

etc) 

3) Symptoms begin or get 

worse afterward

4) Presented with symptoms in 

the past week 

Only patients with both possible 

history of TBI and current 

symptoms referred for 

evaluation 

Exclusion: Did not report 

altered mental status or LOC 

post injury, altered mental 

status for > 24 hr post-injury or 

LOC for > 30 mins; incomplete 

data

N = 339 with mTBI (n = 138 blast, n = 

56 non-blast)

2 VAMCs 

Age (years): 

-Blast: 30 

-Non-blast: 33 (P = .02)

Gender (% male): 

-Blast: 99%

-Non-blast: 89%

Cohort years: NR

Rank: NR

Duty/description: NR

Time since exposure:

-Blast: 35 months

-Non-blast: 42 months 

Duration of deployment: NR

Rural or urban residence: NR

PSTD Checklist (PCL): self-report, 

17 items (rated 1-5 with 1 = not at 

all and 5 = extremely)

Neurobehavioral Symptom 

Inventory (NSI): self-report; 22 

items (rated 0-4 with 0 = none and 

4 = very severe) 

Injury Questionnaire: date(s), 

mechanism(s) (ie, fall, motor 

vehicle, bullet, blast or a 

combination), and number of 

deployment related injuries
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

74

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Luethcke, 201117

Funding Source:

No sources of financial 

support

Inclusion: Military and civilian 

contractors referred to 

outpatient TBI Clinic at a 

forward-deployed combat 

support hospital (CSH) in Iraq 

(OIF); assessed within 72 hr of 

injury; meeting the DoD and VA 

criteria for mild TBI

Exclusion: none reported

NOTE: Blast injury defined as 

primary blast injury (blast 

wave); “non-blast” injury 

included secondary, tertiary, or 

quaternary blast injuries plus 

injuries not involving blasts

N = 82 (n = 40 blast, n = 42 nonblast)

Age (years)

-Blast: 27.1

-Non-blast: 26.6 (P = .73)

Gender (% male) 

-Blast: 98%

-Non-blast: 91% (P = .18)

Cohort years: NR

Rank (P = .07)

Junior enlisted (E1-E4): 

-Blast: 63%

-Non-blast: 61%

Duty/description (P = .20)

Active duty:

-Blast: 53%

-Non-blast: 74%

Blast exposure history: NR

Time since exposure:

-Blast: 1.5 days

-Non-blast: 1.6 days

Duration of deployment (mean): 4.8 

months

Rural or urban residence: NR

Concussive Symptoms: Self-report 

and clinical interview

Automated Neuropsychological 

Assessment Metrics (ANAM): 6 

cognitive domains reported in 2 

dimensions (speed, accuracy)

PTSD Checklist – Military (PCLM): 17 items, self-report

Behavioral Health Measure 

(BHM): 20 items, self-report

Insomnia Severity Index (ISI): 7 

items
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Mac Donald, 201418

Funding Source: 

Congressionally 

Directed Medical 

Research program

Inclusion: Active duty US 

military evacuated from Iraq or 

Afghanistan to Landstuhl 

Regional Medical Center 

(Germany); met DoD criteria for 

TBI

Exclusion: none reported

Followed 6-12 months after 

injury at Washington University 

in St. Louis

NOTE: blast plus impact TBI 

group had blast exposure plus 

another mechanism of head 

injury (eg, fall, motor vehicle 

crash, strike by blunt object); 

non-blast TBI group 

experienced falls, motor vehicle 

crashes, blunt object strikes 

without blast exposure

N = 178 with follow-up data including 

n = 53 blast plus impact TBI, n = 29 

non-blast TBI* 

Age (years): 

-Blast: 25 (median)

-Non-blast: 27 (median)

Gender (% male): 

-Blast: 95

-Non-blast: 91

Cohort years: NR

Rank:

Enlisted: 

-Blast: 97%

-Non-blast: 95%

Duty/description:

Active duty: 

-Blast: 76%

-Non-blast: 73%

Blast exposure history: NR

Time since exposure (for initial 

evaluation):

-Blast: 11.5 days

-Non-blast: 13.8 days

Duration of deployment: NR

Rural or urban residence: NR

*data for n = 96 without TBI not 

included in this review

Glasgow Outcome ScaleExtended: monthly telephone or email for 6-12 months

In-person

1. Standard neurological exam

a. Structured interview 

(Neurobehavioral Rating ScaleRevised)

b. 2 headache interviews capturing 

recent frequency and intensity 

(Migraine Disability Assessment 

[MIDAS] & Headache Impact Test 

6)

c. Neurological Outcomes scale 

for Traumatic Brain Injury (NOSTBI)

2. Neuropsychological test battery 

- 9 standard quantitative tests

3. Psychiatric evaluation

a. Clinician-Administered PTSD 

scale for DSM-IV (CAPS)

b. Montgomery-Asberg 

Depression Rating Scale

c. Combat Exposures Scale (CES)

d. Michigan Alcoholism Screening 

Test
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

76

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

MacGregor, 201120

Funding Source: US 

Navy Medicine Bureau 

of Medicine and 

Surgery

EMED

Inclusion: Sustained TBI in OIF; 

identified from EMED with 

query for all personnel injured 

during OIF (3/2004 to 4/2008) 

who completed PostDeployment Health 

Assessment (PDHA) and PostDeployment Health ReAssessment (PDHRA); both 

surveys completed within 1 

year of injury date

N = 2074 (n = 1987 blast, n = 87 nonblast)

Age (years): 22 

Gender (% male): 99.5% 

Enlisted: 96% (49% E1-E2, 40% E4-

E6)

Cohort years: 2004-2008

Rank: 

- Enlisted: 96%

Duty/description: Infantry 58%

Blast exposure history: NR

Time since exposure: <1 year

Duration of deployment: NR

Rural or urban residence: NR

Abbreviated Injury Scale (AIS): 

TBI severity (mild = 1 or 2, 

moderate = 3, severe = 4, 5, or 6)

Concomitant injuries

Maguen, 201240

Funding Source: 

Supported by 

Department of Defense 

Psychological Health 

and Traumatic Brain 

Injury Research 

Program and VA 

Health Sciences 

Research and 

Development Career 

Development Award

Inclusion: OEF/OIF Veterans 

who received a TBI screen at a 

VA from April 1, 2007 through 

Jan 8, 2010; either reported no 

head injury or both a head 

injury mechanism and TBIrelated symptoms

Exclusion: Previously screened 

elsewhere and data not 

available; previous TBI 

diagnosis; refused screening; 

reported head injury with 

unknown mechanism or no TBI 

symptoms; incomplete screen

N = 1,082 (968 for PTSD analysis)

N = 152 with 1 mechanism of injury 

(n = 103 blast)

N = 310 with 2+ mechanisms of injury 

(n = 287 blast + other) 

Age (years): 29.5

Gender (% male): 95% 

Cohort years: 2007-2010

Rank: Enlisted: 96%

Duty/description: Active duty: 70%

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR (42% 

with multiple deployments)

Rural or urban residence: NR

Primary Care PTSD Screen (PCPTSD): 4 item self-report 

screening instrument 

Patient Health Questionnaire-2 

(PHQ-2): 2 item self-report 

screening instrument; responses 

on 4 point scale (0-3); score ≥ 3 is 

positive screen for depression

Alcohol Use Disorders 

Identification Test Consumption 

(AUDIT-C): 3 item self-report 

screening instrument; total score 

from 0 to 12; ≥4 for men or ≥3 for 

women is positive screen for 

hazardous or harmful consumption
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

77

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Mendez, 201342

Mendez, 201341

Funding Source:

Veterans Affairs 

Administration

Inclusion: Recent US Veterans 

of Iraq or Afghanistan wars; 

presented at VAMC for Second 

Level TBI evaluation; 

community dwelling 

outpatients; reported 

deployment-related mTBI and 

met DoD/VA criteria for mTBI; 

history of primary blast or 

primary blunt force mTBI; 

patient reported persistent 

symptoms they attributed to 

mTBI; medically and 

psychiatrically stable; 

availability of significant other 

informant willing to participate 

in study

 

Exclusion: Mixed TBI; blunt 

controls with blast 

exposure/effects; PTSD, 

depression, or other mental 

illness; intervening head 

injuries, focal neurological 

deficits, visual impairments 

sufficient to impair reading, or 

abnormalities on prior, 

clinically-obtained brain 

imaging (magnetic resonance 

imaging (MRI) or computerized 

tomography (CT)) 

NOTE: blast is primary blast 

force only

N = 24 (n = 12 blast, n = 12 blunt)

Age (years):

-Blast: 31

-Blunt: 31

Gender (% male): NR

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history: 33% (4/12) 

reported multiple “pure” blast 

exposures related to combat duties

Time since exposure:

-Blast: 52 months

-Blunt: 49 months 

Duration of deployment: NR

Rural or urban residence: NR

NOTE: of 12 blast injury subjects, 10 

reported distances of < 10 feet from 

blast exposure, 1 reported < 30 feet, 

1 reported < 50 feet

Mendez 201342:

-Neurobehavioral Symptom 

Inventory (NSI) self-report of 

difficulties on 22 symptoms; 5 

point scale (4 = very severe)

-Rivermead Post-Concussion 

Symptom Questionnaire (RPQ): 

16 symptoms, self-rate degree to 

which symptoms are more of a 

problem compared with premorbid 

levels; scale of 0 (no change) to 4 

(most severe symptoms) 

-Health Related Quality of Life 36-

item Short Form for Veterans 

(SF36-V): self -administered; 8 

subscales and 2 summary scores 

(physical, mental)

-Paced Auditory Serial Addition 

Test (PASAT): cognitive; single 

digits presented at 3 second 

intervals; patient adds new digit to 

one immediately prior

-Iowa Gambling Test (IGT): mental 

flexibility and decision-making 

ability; calculated by 

advantageous minus 

disadvantageous card selections

-Frontal Assessment Battery 

(FAB): six executive operations; 

items rated 0-3; lower scores 

indicate greater impairment

Mendez 201341: 

-Interpersonal Measure of 

Psychopathy (IM-P): interpersonal 

behaviors associated with 

psychopathy

-Big Five Inventory (BFI): 5-factor 

model of personality

-Interpersonal Adjectives Scale 

(IAS): primary dimensions of 
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

78

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

interpersonal transaction

-Frontal Systems Behavior Scale 

(FrSBe): dimension of apathy and 

disinhibition and executive 

dysfunction

Mora, 200943

Funding Source: None 

reported

a Inclusion: OEF/OIF combat 

casualties injured in explosions 

and treated at USAISR Burn 

Center March 2003 to March 

2006; PLC-M assessment at 

least 30 days post-injury

NOTE: Blast is IED with 

primary blast injury; non-blast is 

IED without primary blast injury

N = 19 with mTBI (n = 6 blast, n = 13 

non-blast)

Age (years): 

-Blast: 28

-Non-blast: 29

Gender (%male): 

-Blast: 83%

-Non-blast: 86% 

Cohort years: 2003-2006

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure:

-Blast 117 days

-Non-blast: 233 days 

Duration of deployment: NR

Rural or urban residence: NR

PCL-M: 17 item self-report; PTSD 

indicated by score of 44 and 

above
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

79

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Nakase-Richardson, 

201344

Funding Source:

Veterans Affairs Health 

Services Research and 

Development/

Rehabilitation 

Research and 

Development Center of 

Excellence for 

Maximizing 

Rehabilitation 

Outcomes

Inclusion: Consecutive 

admissions to Polytrauma 

Rehabilitation System of Care 

(Jan 2004 to Oct 2009) with a 

disorder of consciousness 

(DOC)

Exclusion: none reported

N = 122 (29 blast, 10 penetrating, 67 

other trauma, 16 non-trauma*)

Age (years, median): 

-Blast: 25

-Non-blast: 25

Gender (% male): 

-Blast: 100

-Non-blast: 95

Cohort years: 2004-2009

Rank: NR

Duty/description – Active duty: 

-Blast: 97

-Non-blast: 80

Blast exposure history: NR

Time since exposure(median):

-Blast: 67 days

-Non-blast: 46 days (P = .04)

Duration of deployment: NR

Rural or urban residence: NR

*Non-trauma patients not included in 

non-blast group

-Rancho Levels of Cognitive 

Functioning Scale (LCFS): 8 level 

index; awareness, behavioral 

competence and environmental 

interaction; higher levels = greater 

cognitive functioning

-Functional Independence 

Measure (FIM): 18 items; 

functional independence in selfcare and cognition; higher scores

= greater level of independence; 

cognitive and motor subscales

-Return to consciousness: 

assessed with Coma Recovery 

Scale-Revised (CRS-R) or 

evidence of interactive 

communication, functional object

use during self-care tasks, or 

Rancho LCFS score ≥4

Oleksiak, 201245

Funding Source: VA 

Office of Research and 

Development, Health 

Services Research and 

Development grant

Inclusion: Confirmed diagnosis 

of mTBI

Exclusion: moderate/severe 

TBI, prior history of ear disease 

or hearing loss, non-VA care 

for hearing loss

N = 189 (n = 154 blast or mixed, n = 

35 non-blast)

Age (years): 27.9

Gender (% male): 92%

Cohort years: 2007-2009

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

Comprehensive 2nd level TBI 

evaluation 

Neurobehavioral Symptom 

Inventory (NSI): 22 symptoms 

including hearing difficulty
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

80

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Pogoda, 201246

Funding Source:

VA Office of Research 

and Development, 

Health Services 

Research and 

Development Service

Defense 

Management Data 

Center

Inclusion: Veterans completing 

VA CTBIE Oct 2007 to June 

2009; did not report brain injury 

pre-deployment or since 

returning from deployment; met 

criteria for mTBI history (selfreport); VA clinician-confirmed 

deployment related mTBI 

history

Exclusion: none reported

N = 9,998 (n = 8,038 blast, n = 1,960 

non-blast/etiology NR)

Age(years): 31*

Gender (% male): 95% 

Cohort years: 2007-2009

Rank: 

-Junior Enlisted 52%

-Mid-level Enlisted 39%

-Senior Enlisted/Officer 9%

Duty/description: NR

Blast exposure history: NR

Time since exposure: NR

Duration of deployment: NR

Rural or urban residence: NR

*demographic information not 

reported for blast vs non-blast mTBI

Diagnostic codes for depression 

and PTSD (2007- 2009)

Comprehensive Traumatic Brain 

Injury Evaluation (CTBIE): 

performed by VA clinician

Neurobehavioral Symptom 

Inventory (NSI -22): patient selfreport checklist administered 

during CTBIE; rate extent to which 

each symptom has affected them 

in past 30 days from 0 (none) to 4 

(very severe)

Reid, 201447

Funding Source: None 

reported

Inclusion: service members 

evaluated at 1 of 6 Military 

Medical Centers (all in US); 

CHI only; valid and complete 

PCL-C and NSI; injury 

sustained in OEF/OIF; tested 1-

24 months post-injury; mTBI 

associated with most recent 

blast exposure; male

Exclusion: missing data 

regarding number of previous 

blast exposures; exposure to 

>10 blasts

NOTE: unknown whether 

prior blast exposures 

resulted in undocumented 

mTBI

N = 573 (n = 505 blast, n = 68 nonblast)

Age (years): 27

Gender (% male); 100%

Cohort years: NR

Rank: 

-E1-4: 59%

-E5+: 41%

Duty/description: NR

Blast exposure history:

1 blast: n = 123

2 blasts: n = 178

3 blasts: n = 106

4-10 blasts: n = 98

Time since exposure: 1-24 months

Duration of deployment: NR; 

Rural or urban residence: NR

Neurobehavioral Symptom 

Inventory (NSI -22): 

presence/severity of each 

symptom within past 2 weeks; 0 = 

none, 4 = very severe; total score 

and subscales (cognitive, 

affective, sensory, somatic)

Posttraumatic Checklist – Civilian 

version (PCL-C): self-rated, 17 

items (clusters for re-experiencing, 

avoidance, hyperarousal); how 

much bothered by symptom in 

past month; 1 = not at all, 5 = 

extremely; scores range from 17 to 

85
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Sayer, 200848

Funding Source: VA 

Health Service 

Research and 

Development grant

Inclusion: all service members 

injuries in OEF/OIF and 

receiving inpatient VA 

rehabilitation services at a 

polytrauma rehabilitation center 

(PRC)

Exclusion: none reported

N = 188 (n = 106 blast, n = 82 nonblast); 97% with TBI

Age (years): 28

Gender (% male): 97%

Cohort years: 2001-2006

Rank: NR

Duty/description: 74% active duty, 

26% Reserves/National Guard

Blast exposure history: 6 with injuries 

secondary to >1 blast

Time since exposure: 87 days

Duration of deployment: NR

Rural or urban residence: NR

Mortality from VA administrative 

database

Impairments in body structures 

and organs from medical records; 

classified using World Health 

Organization International 

Classification of Functioning, 

Disability and Health

Psychiatric symptoms from 

medical records: PTSD, anxiety 

disorders other than PTSD, 

depression, psychosis

Functional Independence Measure 

(FIM): 13 motor items, 5 cognitive 

items

Schneiderman, 200823

Funding Source: 

Department of 

Veterans Affairs, WarRelated Illness and 

Injury Study Center

Inclusion: responded to selfadministered mail 

questionnaire (addresses/info 

obtained from National Change 

of Address databased and the 

US Department of Defense); 

OEF/OIF Veterans who left 

combat theaters by 9/30/2004; 

living in northern Virginia, 

Maryland, Washington DC or 

eastern West Virginia; active 

duty personnel separated from 

the military and National 

Guard/Reserve members were 

eligible

Exclusion: none reported

N = 2,235 surveys returned (34% 

response)

N = 275 with mTBI (n = 70 blast, n = 

205 non-blast)

Age (years): NR

Gender (% male): 86%

Cohort years: OEF/OIF before 

9/30/2004

Rank: NR

Duty/description: 27% active duty

Blast exposure history: NR

Time since exposure: “left combat 

theaters at least 5 months earlier”

Duration of deployment: NR

Rural or urban residence: NR

3-item Brief Traumatic Brain Injury 

Screen for diagnosis of mTBI

PCS 3+: self-attribution of ≥3 

current neuropsychiatric 

symptoms to possible head injury 

or concussion
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

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Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Wilk, 201021

Funding Source: None 

reported

Inclusion: US soldiers from one 

National Guard and 2 Active 

Duty infantry brigades; 

surveyed in 2006 and 2007 (3-

6 months after return from 

combat deployment to Iraq); 

consented and completed 

some portion of the 

questionnaire (N = 4,383)

Exclusion: none reported

N = 574 with concussion data (15% 

of 3,952 who completed concussion 

questions)

Age (years): 67% <30 years

Gender (% male): 98

Cohort years: 

Rank: Junior Enlisted 53%

Duty/description: “soldiers in this 

study saw high levels of combat”

Blast exposure history: NR

Time since exposure: NR (surveyed 

3-6 months post-deployment)

Duration of deployment: 1 year

Rural or urban residence: NR

Concussion (mTBI): self-report of 

“dazed, confused, or seeing stars,“ 

“not remembering the injury,” or 

“losing consciousness” as a result 

of injury during deployment

Patient Health Questionnaire 15-

item scale (PHQ-15): how much 

individual has been bothered by 

each symptom in past 4 weeks (0

= not, 2 = bothered a lot); high 

severity is score ≥15

Posttraumatic Stress Disorder 

Checklist 17-item (PCL-17): PTSD 

defined by presence of intrusion, 

avoidance, and hyperarousal 

symptoms with total score ≥50

PHQ depression module (PHQ-9): 

depression defined as ≥5 DSM-IV 

symptoms and functional 

impairment at very difficult or 

extremely difficult level 

Two-Item Conjoint Screen for 

Alcohol (modified): alcohol misuse 

defined by positive answer on 

either item
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

83

Author, Year

Funding Source

Data Source

Registry/ Inclusion/Exclusion Criteria Cohort Characteristics Measures

Database

Clinical 

Cohort

Wojcik, 201019

Funding Source: None 

reported

Defense 

Manpower 

Data Center; 

Standard 

Inpatient 

Data Record 

(Army); 

Defense 

Casualty 

Information 

Processing 

System 

(Army); Joint 

Theater 

Trauma 

Registry

Inclusion: hospitalized in Army 

facility in-theater, Europe, or 

US; TBI 

Exclusion: none reported

N = 2,448 episodes of hospitalization 

with TBI (n = 1,388 episodes with 

mechanism of injury data: 871 blast, 

517 non-blast)

Age (years): mean NR (66% of all 

TBI hospitalizations in 20-29 year 

range)

Gender (% male): 97.5% (all TBI 

hospitalizations)

Cohort years: 2001-2007

Rank: 93% enlisted, 7% officers (all 

TBI hospitalizations)

Duty/description: 76% active duty; 

also 66% combat, 16% combat 

service, 13% combat service support, 

5% unknown

Blast exposure history: NR

Time since exposure: <30 days

Duration of deployment: NR

Rural or urban residence: NR

TBI severity (based on ICD-9-CM 

codes and Barell Matrix 

classification):

-Type 1 [most severe]

-Type 2

-Type 3 [least severe])

Xydakis, 201224

Funding Source: None 

reported

Inclusion: consecutive 

polytrauma inpatients; 

transported to WRAMC 

following injury during combat 

operations requiring immediate 

stateside evaluation; closed 

head injury (CHI) from blunt or 

blast mechanism

Exclusion: none reported

N = 365 blast CHI, 198 with TBI

N = 102 non-blast CHI, 58 with TBI

Age (years): 24 (blast group only)

Gender (% male): 99 (blast group 

only)

Cohort years: NR

Rank: NR

Duty/description: NR

Blast exposure history: NR

Time since exposure: 8 days 

(median, blast group only)

Duration of deployment: NR

Rural or urban residence: NR

TBI evaluation

BAMC = Brooke Army Medical Center; DoD = Department of Defense; DVBIC = Defense and Veterans Brain Injury Center; EMED = Expeditionary Medical Encounter 

Database; SAMMC = San Antonio Military Medical Center; TPRC = Tampa Polytrauma Rehabilitation Center; VAMC = VA Medical Center; VHA = Veterans Health 

Administration; WRAMC = Walter Reed Army Medical Center; MIRECC = Mental Illness Research, Education, and Clinical Center; PRC = Polytrauma Rehabilitation Center 

(inpatients); PNS = Polytrauma Network Site (outpatients); USAISR = US Army Institute of Surgical Research; mTBI = mild traumatic brain injury; LOC = loss of consciousness; 

NBR = non-blast-related; BR = blast-related; BPPV = benign paroxysmal positional vertigo; cVEMP = cervical vestibular evoked myogenic potential; SVV = subjective visual 

vertical; SOT = sensory organization test; PCL-C = PTSD Checklist – Civilian version PCL-M = PTSD Checklist – Military version; NSI = Neurobehavioral Symptom Inventory; 

CHI = closed head injury; VOR = vestibular-ocular reflex; VSR = vestibular-spinal reflex
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

84

a Patients treated at US Army Institute of Surgical Research (USAISR) Burn Center; medical records obtained from Joint Theater Trauma Registry
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

85

Table 4a. Mortality Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

DuBose, 201113

Blunt: 9.8% (11/112)

Blast (explosion): 8.6% 

(32/374); OR 0.66 (0.31, 1.41)

Gunshot: 6.8% (8/118); OR 

0.60 (0.19, 1.89)

Sayer, 200848 3% (3/106) 1% (1/82); P = 

.63

Table 4b. PTSD Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Belanger, 200926 PCL:

41.1 (18.0)

PCL:

32.9 (17.2); P<.07

Belanger, 201127

PCL:

41.5 (17.4)

PCL:

37.3 (17.6); 

P = .047

Clark, 200929 PTSD diagnosis:

45.1%

PTSD diagnosis:

11.8%; P<.05

Collen, 201231

PTSD

(comorbid 

diagnosis)

60.5%

PTSD

48.6%; P = 

.24

Cooper, 201232

PCL-M:

37.88 (16.42)

PCL-M:

36.29 (14.72); P 

= .696

Goodrich, 201435

PTSD 

diagnosis:

62% (31/50)

PTSD 

diagnosis:

20% (10/50); 

P<.001
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

86

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Kennedy, 201016

PCL-C total: 

44.3 (17.6)

PCL-C > 50:

38.2%

Reexperiencing: 

13.3 (5.9)

Avoidance:

15.8 (7.4)

Hyper-Arousal: 

15.2 (5.6)

PCL-C total: 

42.7 (16.9); P = 

.20

PCL-C > 50:

33.3%; P = .29

Reexperiencing: 

12.0 (5.7); P = 

.02

Avoidance: 

15.6 (7.0); P = 

.83

Hyper-Arousal: 

14.5 (5.7); P = 

.20

Kontos, 201322

PTSD symptoms, 

Mean (SD): 22.6 

(8.8)

OR - clinical 

levels of PTSD 

symptoms (blast 

vs blunt): 2.12 

(1.68, 2.66); P = 

.001

Blast history 

dose-responsea

: 

a. Symptom 

scores increased 

significantly with 

increased number 

of diagnosed blast 

mTBIs

b. OR for clinical 

levels of PTSD 

symptoms 

significant for 3+ 

blasts vs 1 blast 

but not 2 vs 1 or 

3+ vs 2

PTSD symptoms:

20.3 (7.1); P<.01
Combat Blast Injuries 2001-2014 Evidence-based Synthesis Program

87

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Lippa, 201039

PCL total 

Mean (SD): 

54. 5 (15.0)

PCL total 

≥ 50

89/138 

(64.5%)

PCL total:

49.8 (15.1); 

P = .054

PCL total 

≥ 50 

25/56 

(44.6%); 

P<.05

Luethcke, 201117

Blast is primary blast 

Non-blast includes 

secondary, tertiary, 

quaternary, and nonblast

PCL-M 

Mean (SD) 

27.8 (8.9)

PCL-M 

Mean (SD) 

26.7 (13.2); 

P = .33

Mac Donald, 201418

Blast is blast plus 

other mechanism of 

head injury

Non-blast is other 

mechanism of head 

injury only

PTSD

22/53 (42%) 

PTSD

14/29 (48%); P 

= .56 

PTSD Severity

P = .90
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Maguen, 201240

(n = 968 for PTSD 

analysis)

PTSD positive 

screen

Blast only head 

injury: 55/90 (61%)

OR 4.7 (2.9, 7.7)*

Blast plus other 

mechanism of 

head injury :

185/266 (70%) OR 

6.5 (4.6, 9.3)* 

PTSD positive 

screen

1 Non-blast head 

injury:

25/43 (58%) 

OR 4.6 (2.4, 8.8)*

2+ Non-blast head 

injuries:

9/19 (47%) 

OR 3.4 (1.3, 8.6)*

*Reference for all 

ORs is TBI with no 

head injury 

(129/550; 24%)

Mora, 200943

Blast is IED exposure 

with primary blast 

injury

Non-blast is IED 

exposure without 

primary blast injury

PTSD

Prevalence:

67% (4/6)

PTSD 

Prevalence:

21% (3/13); P = 

.13 (calculated)

Reid, 201447

PCL-C

Mean (SD); P = .016 across groups

Non-blast: 42.9 (18.2)

1 blast: 34.9 (17.1)

2 blasts: 41.5 (16.5)

3 blasts: 45.8 (17.5)

4-10 blasts: 46.5 (17.5)

Sayer, 200848

PTSD 

Symptoms:

42% (45/106)

PTSD 

Symptoms:

24% (20/82); 

P<.01
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Wilk, 201021

PTSD 

Diagnosis

LOC:

72/161 (45%) 

CIC: 

79/263 (30%) 

PTSD 

Diagnosis

LOC: 15/39 

(39%); P = .59 

CIC:

32/110 (29%); P 

= .90 

CIC = concussion with change in consciousness; LOC = concussion with loss of consciousness; NSI = Neurobehavioral Symptom Inventory; PCL = Post-traumatic Stress Disorder 

Checklist; PCL-M = PCL Military version; PCL-C = PCL Civilian version a Analysis includes blast-only mTBI and combination blast-blunt mTB
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Table 4c. Pain Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Clark, 200929

Pain intensity 

(NRS):

5.4 (2.3)

Number of 

pain sites:

2.4 (1.3)

Pain 

intensity:

4.4 (2.8); P = 

NS

Number of 

pain sites:

2.0 (1.5); P = 

NS

Sayer, 200848 Impairment:

83% (88/106)

Impairment:

80% (65/82); P = NS

Wilk, 201021

Stomach pain

LOC:

13/156 (8.3%)

CIC:

14/254 (5.5%)

Back pain

LOC:

71/157 (45.2%)

CIC:

84/257 (32.7%)

Arm, leg or joint 

pain

LOC:

78/156 (50.0%)

CIC:

105/256 (41.0%)

Stomach pain

LOC:

4/40 (10.0%); P = .76

CIC:

16/107 (15.0%); P = 

.01

Back pain

LOC:

14/40 (35.0%); P = 

.29

CIC:

36/108 (33.3); P = .90

Arm, leg or joint 

pain

LOC:

17/40 (42.5); P = .48

CIC:

54/107 (50.5); P = .11

CIC = concussion with change in consciousness; LOC = concussion with loss of consciousness; NRS = Pain Numeric Rating Scale (0 = no pain, 10 = worst pain)
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Table 4d. Burn Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Clark, 200929

Burn 

diagnosis:

9.9%

Burn 

diagnosis:

2.1%; P = NS

Mora, 200943

Blast is IED exposure with 

primary blast injury

Non-blast is IED exposure 

without primary blast injury

TBSA 8.1% 

(6.9%)

17.0% 

(10.6%); 

P = NR

Sayer, 200848

Skin or soft 

tissue burn 

injury: 13% 

(14/106)

Skin or soft 

tissue burn 

injury: 4% 

(3/62); P<.05

TBSA = total body surface area

Table 4e. Limb Loss Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Clark, 200929 Amputation:

16.0%

Amputation:

2.9%; P<.05

Sayer, 200848

Amputation:

9% (10/106)

Amputation:

2% (2/82)

P<.10 (NS)
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Table 4f. Vision Loss Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Brahm, 200928

NOTE: Inpatients 

had moderate/severe 

TBI; outpatients had 

mTBI

Inpatients

Subjective visual 

complaint: 77% 

(41/53)

Ocular injury: 44% 

(25/57)

Legally blind: 9% 

(5/54)

Outpatients

Subjective visual 

complaint: 76% 

(85/112)

Ocular injury: 7% 

(8/112)

Legally blind: 2% 

(2/112) 

Inpatients

Subjective visual 

complaint: 63% 

(5/8); P = .39

Ocular injury: 9% 

(1/11); P = .04

Legally blind: 33% 

(3/9); P = .08

Outpatients

Subjective visual 

complaint: 75% 

(9/12); P = 1.0

Ocular injury: 17% 

(2/12); P = .25

Legally blind:

(0/12); P = 1.0

Clark, 200929 Eye injury:

37.5%

Eye injury:

23.5%; P = NS

Cockerham, 201330

(NOTE: Analyses of 

blast/non-blast were 

considered 

exploratory due to 

small size of nonblast sample; OSDI 

and dry eye disease 

measures were 

reported to be similar 

for blast and nonblast TBI) 

OSDI:

mean (SD): 

21 (25) n = 44

Tear production 

< 4mm:

17 /44 (39%)

Tear osmolarity: 

>314:

13/24 (54%)

Ocular surface 

staining: 35/44 

(80%)

OSDI:

16 (13) n = 9 

Tear 

production < 

4mm:

2/9 (22%)

Tear 

osmolarity 

>314:

6/9 (67%)

Ocular surface 

staining: 7/9 

(78%)
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Goodrich, 201334

Ocular injury:

31% (15/49) 

Monocular 

vision: 12% 

(6/50)

Vision 

complaints: 66% 

(33/50)

Light sensitivity: 

67% (31/46)

Reading 

complaints:

56% (27/48)

Visual acuity 

poor (worse 

eye): 28% 

(15/50)

Ocular Injury:

29% (14/49); P 

= 1.0

Monocular 

vision: 2% 

(1/5); P = .112

Vision 

complaints: 

69% (34/49); P 

= NS

Light 

sensitivity: 

33% (13/40); P 

= .002

Reading 

complaints:

47% (20/43); 

P = NS

Visual acuity 

poor (worse 

eye): 18% 

(9/50); P = .34

Lew, 201114

Visual impairment 

only: 8.8% 

(918/10431)

(blast exposure 

was significant 

predictor of visual 

impairment with 

more with non-blast 

TBI reporting 

severe impairment 

P≤.001)

Visual impairment 

only: 15.7% 

(328/2090); P<.001 

(calculated)
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI

Luethcke, 201117

Blast is primary blast 

Non-blast includes 

secondary, tertiary, 

quaternary, and nonblast

Symptoms

Immediate 

7/40 (18%) 

Current 

5/40 (13%)

Symptoms

Immediate 

12/42 (29%); 

P = .24

Current 

4/42 (10%); 

P = .67

Reid, 201447

NSI Vision Problems

Mean (SD); P<.001 across groups 

adjusted for demographics and loss of 

consciousness

Non-blast: 0.83 (1.02) 

1 blast: 0.58 (0.84)

2 blasts: 0.97 (1.12)

3 blasts: 1.14 (1.17)

4-10 blasts: 1.20 (1.21)

Sayer, 200848

Eye injury: 47% 

(50/206)

Vision 

impairment

58% (61/106)

Eye injury: 

26% (21/82); 

P<.01

Vision 

impairment:

46% (38/82); P 

= NS

OSDI = Ocular Surface Disease Index; SD = standard deviation

Table 4g. Hearing Loss Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Clark, 200929

Hearing 

problems

35.3%

Hearing 

problems

32.4%; P = NS
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Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Lew, 201114

Auditory 

impairment 

only: 33.1% 

(3453/10431)

(blast exposure 

was significant 

predictor of 

auditory 

impairment; 

P≤.001)

Dual sensory 

impairment:

35.4% 

(3692/10431)

Auditory 

impairment 

only: 22.7% 

(474/2090); 

P<.001

(calculated)

Dual sensory 

impairment:

30.3% 

(622/2090); 

P<.001 

(calculated)

Lew, 200738

Hearing loss: 

62% (26/42)

Tinnitus: 38% 

(16/42)

Hearing loss: 

44% (48/108); P 

= .04

Tinnitus: 18%

(19/108); P = 

.007

Luethcke, 201117

Blast is primary blast 

Non-blast includes 

secondary, tertiary, 

quaternary, and nonblast

Symptoms

Immediate 

21/40 (53%) 

Current 

9/40 (23%)

Symptoms

Immediate 

7/42 (17%); P 

= .001 

Current 

4/42 (10%); P 

= .11

Mac Donald, 201418

Blast is blast plus other 

mechanism of head 

injury

Non-blast is other 

mechanism of head 

injury only

Hearing 

deficit 10/53

(19%)

Hearing 

deficit

4/29 (14%); P 

= NS
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Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Oleksiak, 201245

NSI-Hearing 

Difficulty score

Blast: 1.99 

(0.98)

Mixed: 1.83 

(1.04)a 

Primary Blast: 

2.09 (0.98)

Secondary Blast: 

1.81 (0.87); P = 

NS between 

blast types

% with score 

>1b 

Blast: 93%

Mixed: 88%

Primary blast: 

94%

Secondary blast: 

100%

NSI-Hearing 

Difficulty score

Fall: 1.92 (1.15)

Vehicle: 1.50 

(1.08); 

P = NS across 

groups

% with score 

>1

Fall: 84%

Vehicle: 80%

Reid, 201447

NSI Hearing Difficulty

Mean (SD); P<.001 across groups 

adjusted for demographics and loss 

of consciousness

Non-blast: 1.10 (0.99) 

1 blast: 1.48 (1.16)

2 blasts: 1.34 (1.19)

3 blasts: 1.53 (1.17)

4-10 blasts: 1.84 (1.08)
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Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Sayer, 200848

Otologic 

injury: 46% 

(49/106) 

Hearing 

loss: 48% 

(51/106)

Tinnitus: 

26% (28/106)

Otologic 

injury: 23% 

(19/82); 

P<.01 

Hearing 

loss: 33% 

(27/82); 

P<.05

Tinnitus: 

12% (10/82); 

P<.05

Wilk, 201021

Ringing in 

Ears

LOC 53/154 

(34.4%) 

CIC 57/257 

(22.2%) 

Ringing in 

Ears

LOC 6/40 

(15%); P = 

.02

CIC 18/106 

(17.0%); P = 

.32

CIC = concussion with change in consciousness; LOC = concussion with loss of consciousness; NSI = Neurobehavioral Symptom Inventory (0 = no hearing loss, 4 = very severe 

hearing loss)

a Mixed = any combination of accident types b Score > 1 is mild or more severe hearing loss
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Table 4h. Vestibular Dysfunction Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Akin, 201115

DHI: 58.9 (mean) 

(score of > 54 = 

severe)

SOT

-abnormal: 8/9 

(89%)

-normal: 1/9 

(11%)

DHI: 41.8 (mean) 

(scores of 36 to 

52 = moderate)

SOT

-abnormal: 5/9 

(56%); P = .29

(calculated)

-normal: 2/9 

(22%)

-did not 

complete: 2/9 

(22%)

Hoffer, 200936

VOR study: Descriptive differences 

between blunt and blast for phase 

and symmetry; no difference in gain 

function

VSR study:

Sensory organization test (SOT): 

Trend toward significantly better 

scores for blunt exposure groups, 

particularly if migraine-associated 

dizziness diagnosis

Motor Control Test (MCT): 

Significantly more patients in blast 

groups had abnormal latency times 
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Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Luethcke, 201117

Blast is primary blast 

Non-blast includes 

secondary, tertiary, 

quaternary, and nonblast

Balance 

Symptoms: 

Immediate

10/40 (25%) 

Current 

3/40 (8%)

Dizziness 

Symptoms

Immediate 

22/40 (55%)

Current 

7/40 (18%)

Balance 

Symptoms: 

Immediate

19/42 (45%); P 

= .06

Current 

symptoms:

5/41 (12%); P 

= .50

Dizziness 

Symptoms

Immediate 

28/42 (67%); P 

= .28

Current 

9/42 (21%); P 

= .65

Reid, 201447

NSI Loss of Balance

Mean (SD); P<.001 across groups 

adjusted for demographics and loss 

of consciousness

Non-blast: 0.98 (1.07) 

1 blast: 0.72 (0.86)

2 blasts: 0.87 (0.95)

3 blasts: 1.18 (1.08)

4-10 blasts: 1.28 (0.91)

Sayer, 200848

Balance/

equilibrium 

impairment: 

68% (72/106)
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Author, Year Short-term (< 30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Wilk, 201021

Dizziness

LOC: 15/155 

(9.7%)

CIC: 16/258 

(6.2%)

Balance 

Problems

LOC: 14/155 

(9.0%)

CIC: 17/258 

(6.6%) 

Dizziness 

LOC: 5/40 

(12.5%); P = 

.57

CIC: 7/107 

(6.5%); P = 1.0

Balance 

Problems

LOC: 6/40 

(15.0%); P = 

.26

CIC: 6/106 

(5.7%); P = .82

CIC = concussion with change in consciousness; LOC = concussion with loss of consciousness; DHI = Dizziness Handicap Inventory (higher score = greater perceived handicap 

due to dizziness); SOT = Sensory Organization Test (composite equilibrium); VOR = vestibular-ocular reflex; VSR = vestibular-spinal reflex
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Table 4i. Cognitive Function Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Belanger, 200926

Trail Making Test 

WAIS-III

BVMT-Ra 

CLVT-II

No between-subjects effect for 

TBI etiology

Clark, 200929

Rancho Score

6.3 (1.4)

Rancho 

Score

6.0 (1.0); P = 

NS

Cooper, 201232

RBANS – total:

94.88 (12.92)

98.62 (9.33); P = 

.211

(Groups also 

similar on all 

RBANS 

subscales)

Kontos, 201322

Verbal memory:

90.2 (7.9)

Visual memory:

70.3 (13.0)

Visual 

processing 

speed: 

27.5 (4.3)

Reaction time:

1.2 (0.2)

Blast history 

dose-response: 

slower reaction 

time if 3+ blast 

mTBIs vs no 

mTBI; P<.05

All scores: 

mean (SD)

Verbal 

memory: 90.9 

(7.7); P = NS

Visual 

memory:

72.6 (13.2); P 

= .001

Visual 

processing 

speed: 28.3 

(4. 5); P<.01

Reaction 

time: 1.1 

(0.2); P = .001
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Lange, 201237

Neurocognitive Tests: 

Between group differences (P<.05) 

for 2 of 12 measures with non-blast 

group performing worse; similar 

results with adjustment for months 

tested post-injury

Luethcke, 201117

Blast is primary blast 

Non-blast includes 

secondary, tertiary, 

quaternary, and nonblast

ANAM - Cognitive

Across 6 cognitive 

domains, speed (P = .74) 

and accuracy (P = .65) 

scores did not differ by 

injury type (blast/nonblast)

Mendez, 201342

Blast is primary blast 

only

Non-blast is blunt 

injury

Mean (SD)

PASAT 

28.9 (11.1)

FAB 

16.5 (1.4)

IGT

-7.0 (13.6) 

PASAT

44.0 (4.5); P<.001

FAB 

16.7 (2.2); P = NS

IGT

2.2 (17.4); P = NS

Nakase-Richardson, 

201344

Rancho LCFS 

(median)

admission: 3

discharge: 4

FIM-cognitive

(median)

admission: 5

discharge: 7

Rancho LCFS

(median)

admission: 2

discharge: 4 

(penetrating 

trauma), 5 (other 

trauma); 

P = NS

FIM-cognitive

(median)

admission: 5

discharge: 5 

(penetrating), 12 

(other); 

P = NR
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Reid, 201447

NSI Cognitive

Mean (SD) unadjusted; P<.001 

across groups (unadjusted); P = 

.003 across groups adjusted for 

demographics and PCL-C)

Non-blast: 8.3 (5.0) 

1 blast: 6.5 (5.0)

2 blasts: 7.3 (5.2)

3 blasts: 9.0 (5.3)

4-10 blasts: 9.6 (5.2)

Sayer, 200848

Cognition 

impairment: 

88% (93/106)

Cognition 

impairment: 

93% (76/82); P = 

NS

Wilk, 201021

Memory 

Problems 

LOC: 48/154 

(31.2%) 

CIC: 45/257 

(17.5%)

Concentration 

Problems

LOC: 49/155 

(31.6%) 

CIC: 62/255 

(24.3%)

Memory 

Problems

LOC: 12/40 

(30%); P = 1.0

CIC: 33/107 

(30.8%); P = .01

Concentration 

Problems

LOC: 13/38 

(34.2%); P = .85

CIC: 37/106 

(34.9%); P = .05

WAIS-III = Digit Symbol-Coding subset of Wechsler Adult Intelligence Scale-3rd edition; BVMT-R = Brief Visuospatial Memory Test-Revised; CVLT-II = California Verbal 

Learning Test-II; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status; Rancho = Rancho Los Amigos Scale; ANAM = Automated Neuropsychological 

Assessment Metrics; PSAT = Paced Auditory Serial Addition Test; FAB = frontal Assessment Battery; IGT = Iowa Gambling Task; Rancho LCFS = Rancho Levels of Cognitive 

Functioning Scale; FIM = Functional Independence Measure; CIC = concussion with change in consciousness; LOC = concussion with loss of consciousness a Etiology X severity interaction for BVMT-R with highest scores (best performance) for blast-injured mild TBI and lowest scores (worst performance for blast-injured 

moderate/severe TBI (means for non-blast mTBI and moderate/severe TBI were between means for blast mTBI and moderate/severe TBI)
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Table 4j. Quality of Life Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Mendez, 201342 

Blast is primary blast only

Non-blast is blunt injury

SF36-V*

Physical 

Composite

45.3 (9.4)

Mental 

Composite

35.5 (13.2)

*P = NS for all 

sub-scales 

Physical 

44.1 (12.3); P = 

NS

Mental 

37.3 (10.7); P = 

NS

SF36-V = Health Related Quality of Life 36-item Short Form for Veterans 

Table 4k. Functional Status/Employment Outcomes by Time Post-exposure – Key Question 3

Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Clark, 200929

FIM

81.0 (31.8)

FIM

80.1 (30.4); P = 

NS

Mac Donald, 201418

Blast is blast plus 

other mechanism of 

head injury

Non-blast is other 

mechanism of head 

injury only

Global outcome (GOS-E) P = .82

Moderate to severe disability 

(GOS-E ≤6):

-Blast plus impact TBI: 41/53 

(77%)

-Non blast TBI 23/29 (79%); P = 

.84
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Author, Year

Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast

TBI

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Nakase-Richardsion, 

201344

FIM-motor

(median)

admission: 13

discharge:13

FIM-motor

(median)

admission: 13

discharge:13 

(penetrating 

trauma), 28 

(other trauma)

P = .02 for other 

trauma vs blast/

penetrating

Sayer, 200848

Motor 

functioning 

impairment: 

62% (66/106)

Motor 

functioning 

impairment: 

65% (53/82); P = 

NS

Wilk, 201021

≥ 2 missed 

workdays due 

to illness

LOC: 32/156 

(20.5%) 

CIC: 44/260 

(16.9%)

≥ 2 missed 

workdays due 

to illness

LOC: 9/40 

(22.5%); P = .83

CIC: 11/108 

(10.2%); P = .11

FIM = Functional Independence Measure (higher scores = greater independence); GOS-E = Glasgow Outcome Scale-Extended; CIC = concussion with change in consciousness; 

LOC = concussion with loss of consciousness
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Table 4l. Other Outcomes by Time Post-exposure – Key Question 3

Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Belanger, 

201127

NSI

no significant effect for mechanism 

of injury (P = .36)

Clark, 200929

Depression 

diagnosis

25.5%

Any psychiatric 

diagnosis

86.3%

Depression 

diagnosis

14.7%; P = NS

Any psychiatric 

diagnosis

52.9%; P<.05

Collen, 201231

Sleep

Insomnia: 63%

OSAS: 25.9%

ESS: 8.8 (4.6) 

Depression 

(comorbid 

diagnosis)

87.7%

Anxiety 

(comorbid 

diagnosis)

50.6%

Sleep

Insomnia: 40%; 

P = .02

OSAS: 54.3%; 

P = .003

ESS: 11.3 

(5.7); P = .04

Depression 

80%; P = .29

Anxiety 

20%; P = .002

Cooper, 201232 HIT-6:

56.03 (9.54)

54.32 (9.44);

P = .489

Fortier, 201433

mTBI Gradea

I: 14/26 (54%)

II: 11/26 (42%)

III: 1/26 (4%)

mTBI Grade

I: 16/30 (53%)

II: 12/30 (40%)

III: 2/30 (7%); 

P = NS 

(calculated)
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

French, 201425

Injury Severity 

(of 474 with 

blast mTBI)

Minor: 12%

Moderate: 46% 

Serious: 27%

Severe/critical: 

15%

(of 105 with 

non-blast 

mTBI)

Minor: 13%

Moderate: 56% 

Serious: 21%

Severe/critical: 

10%; 

P = .202

Lange, 201237

Personality Assessment 

Inventory (14 items including 

depression, anxiety, alcohol 

problems):

No significant between-group 

differences (P<.05); similar 

results with adjustment for 

months tested post-injury

Lippa, 201039

Post-concussive symptoms 

(cognitive, affective, sensory, 

somatic, and headache) were 

similar (blast vs non-blast) 

Luethcke, 

201117

Blast is primary 

blast 

Non-blast 

includes 

secondary, 

tertiary, 

quaternary, and 

non-blast

Global Mental 

Health 

Mean (SD)

3.5 (0.4)

Insomnia 

Severity Index 

Mean (SD)

7.7 (6.0)

Headache 

Symptoms

Immediate:

28/40 (70%) 

Current 

21/40 (53%) 

Global Mental 

Health 

Mean (SD)

3.4 (0.6); P = .87

Insomnia 

Severity Index 

Mean (SD)

8.2 (6.6); P = .87

Headache 

Symptoms

Immediate:

34/42 (81%); P 

= .25

Current 

symptoms:

35/42 (83%); P 

= .003
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Mac Donald, 

201418

Blast is blast 

plus other 

mechanism of 

head injury

Non-blast is 

other 

mechanism of 

head injury only

Smell (Deficit)

9/53 (17%)

Headache 

(MIDAS): Blast 

and non-blast 

TBI groups 

similar (P = 

.48)

Neuropsychological 

testing:

Blast and nonblast TBI 

groups similar 

(P = NS)

Neurobehavioral 

assessment: 

Blast and nonblast TBI 

groups similar 

(P = NS)

Alcohol 

Misuse: Blast 

and non-blast 

TBI groups 

similar (P = 

NR)

Depression 

Severity: Blast 

and non-blast 

TBI groups 

similar (P = 

.38)

Smell (Deficit)

15/29 (52%); 

P = .0009
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

MacGregor, 

201120

TBI Blastrelated

Mild: 

1822/1852 

(98%)

Moderate: 

76/90 (84%)

Severe: 89/132 

(67%)

Concomitant 

Injuries

Other HNF 

1204/1987 

(61%)

Any extremity 

611/1987 

(31%)

Spine/Back 

Injury

237/1987 

(12%)

TBI Non-blast

Mild: 30/1852 

(2%)

Moderate: 

14/90 (16%)

Severe: 43/132 

(33%); P<.001

Concomitant 

Injuries

Other HNF

41/87 (47%); P 

= .01

Any extremity

22/87 (25%); P 

= .28

Spine/Back

2/87 (3%); P = 

.006
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Maguen, 

201240

(n = 974 for 

depression 

analysis; n = 

968 for alcohol 

analysis)

Depression 

Positive Screen

Blast only head 

injury: 24/86 

(28%) 

OR 2.2 (1.3, 

3.8)*

Blast plus other 

mechanism of 

head injury: 

119/267 (45%) 

OR 4.4 (3.0, 

6.4)*

Alcohol Misuse 

Positive Screen

Blast injury only 

48/89 (54%) 

OR 1.5 (0.9, 

2.5)*

Blast plus other 

mechanism of 

head injury 

143/262 (55%) 

OR1.6 (1.1, 

2.2)*

Depression 

Positive Screen

1 non-blast head 

injury:

15/42 (36%); 

P = .42 

(calculated)

OR 3.2 (1.6, 

6.3)*

2 + non-blast 

head injury:

5/22 (23%) 

OR 1.66 (0.6, 

4.7)*

Alcohol Misuse 

Positive Screen

1 non-blast head 

injury 19/43 

(44%); P = .35 

(calculated)

OR 1.2 (0.6, 

2.2)*

2+non-blast 

head injury 

13/21 (62%) 

OR 2.4 (1.0, 

6.0)*

*Reference is 

TBI with no 

head injury
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Mendez, 201342

Blast is primary 

blast only

Non-blast is 

blunt injury

Mean (SD)

RPQ-Total 

38.0 (8.8) 

NSI 

42.1 (17.8)

IM-P

23.2 (2.3)

RPQ Total 

41.6 (9.2); P = 

NS

NSI

46.2 (10.7); P = 

NS

IM-P

21.3 (0.7); 

P<.001

BFI, FrSBe, 

IAS P = NS for 

all items

Mora, 200943

Blast is IED 

exposure with 

primary blast 

injury

Non-blast is 

IED exposure

without primary 

blast injury

ISS:

7.8 (9.3)

ISS:

15.0 (11.6)

NakaseRichardson, 

201344

Emergence 

from LOC

60%

Emergence 

from LOC

56% 

(penetrating 

trauma)

76% (other 

trauma)

P = .03 for 

other trauma vs 

blast/

penetrating
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Pogoda, 201246

Multisensory Impairment

Reference: no mTBI etiology 

reported

Non-blast only: OR 1.00 (0.80, 

1.25); P = .99

Blast only: OR 1.03 (0.84, 1.25); P

= .81

>1 Non-blast and >1 blast: OR 

1.61 (1.30, 2.00); P<.001

Reid, 201447

NSI (total)

Mean (SD) unadjusted; P<.001 

across groups (unadjusted); P = 

.001 across groups adjusted for 

demographics and PCL-C)

Non-blast: 29.3 (17.9) 

1 blast: 24.1 (16.6)

2 blasts: 27.6 (17.2)

3 blasts: 32.9 (17.7)

4-10 blasts: 35.0 (17.8)

NSI Difficulty Falling or Staying 

Asleep

Mean (SD); P<.001 across groups 

adjusted for demographics and 

loss of consciousness

Non-blast: 2.37 (1.19) 

1 blast: 1.82 (1.30)

2 blasts: 2.21 (1.32)

3 blasts: 2.34 (1.28)

4-10 blasts: 2.55 (1.28)

NSI Feeling Depressed or Sad

Mean (SD) P = .087cross groups 

adjusted for demographics and 

loss of consciousness

Non-blast: 1.14 (1.33) 

1 blast: 0.88 (1.11)

2 blasts: 1.01 (1.11)

3 blasts: 1.21 (1.24)

4-10 blasts: 1.17 (1.22)
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Sayer, 200848

Sleep 

impairment: 

60% (64/106)

Depressive 

symptoms: 

37% (39/106)

Sleep 

impairment: 

57% (47/82); P 

= NS

Depressive 

symptoms: 

38% (29/82); P 

= NS

Schneiderman, 

200823

PCS 3+

Prevalence ratio (PR) = 1.19 (CI 

not reported)

Blast exposure vs non-blast 

(defined as no high-energy injury 

mechanism)

NOTE: PR 1.02 (95% CI 0.69, 

1.52) for any high-energy injury 

mechanism vs none; high-energy 

includes blast, bullet, shrapnel, 

motor vehicle crash, fall, air/water 

transport
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Wilk, 201021

Major 

Depression 

LOC: 33/156 

(21.2%)

CIC: 26/255 

(10.2%)

Sleep 

Problems

LOC: 95/154 

(61.7%) 

CIC: 126/251 

(50.2%) 

Alcohol 

Misuse

LOC: 60/154 

(39.0%) 

CIC: 72/255 

(28.2%) 

Headache

LOC:

63/157 (40.1%)

CIC:

53/258 (20.5%)

Major 

Depression

LOC: 6/38 

(15.8%); P = 

.65

CIC: 17/106 

(16%); P = .15

Sleep 

Problems

LOC: 22/38 

(57.9%); P = 

.71

CIC: 53/106 

(50%); P = 1.0

Alcohol 

Misuse

LOC: 16/38

(42.1%); P = 

.72

CIC: 40/107 

(37.4%); P = 

.11

Headache

LOC:

9/40 (22.5); P = 

.04

CIC:

19/108 (17.6); 

P = .57

Wojcik, 201019

TBI Severitya

(Hospitalization episodes)

Type 1 TBI:

55%

(501/911)Type 

2 TBI:

39% (353/911)

Type 3 TBI:

6% (57/911)

TBI Severityb

(Hospitalization episodes)

Type 1 TBI:

43%

(239/550)Type 2 

TBI:

50% (277/550)

Type 3 TBI:

6% (34/550)

All: P = NR
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Author, Year Short-term (<30 days) Mid-term (30 days to 1 year) Long-term (> 1 year) Not Specified

Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI Blast TBI Non-blast TBI

Xydakis, 201224

TBI Severity

Mild: 68% 

(134/198)

Moderate: 

28% (55/198)

Severe: 5% 

(9/198)

TBI Severity

Mild: 58% 

(34/58)

Moderate: 33% 

(19/58)

Severe: 9% 

(5/58)

All: P = NR

BFI = Big Five Inventory; FrSBe = Frontal Systems Behavior Scale; IAS = Interpersonal Adjectives Scale; IM-P = Interpersonal Measure of Psychopathy; MIDAS = Migraine 

Disability Assessment; NSI = Neurobehavioral Symptom Inventory; RPQ = Rivermead Post-Concussion Symptom Questionnaire; LOC = loss of consciousness; CIC = concussion 

with change in consciousness; PCS 3+ = post concussive symptoms (≥3 persistent); NSI = Neurobehavioral Symptom Inventory (post-concussion symptoms); HIT-6 = Headache 

Impact Test; ESS = Epworth Sleepiness Scale; OSAS = obstructive sleep apnea syndrome; LOC = loss of consciousness; AMS = alteration of mental state; PTA = posttraumatic 

amnesia

a Grade I = no LOC, 0-15 min of AMS, 0-15 min PTA; Grade II = LOC < 5 min, AMS >15 min to < 24 hours, PTA >15 min to < 24 hours; Grade II = LOC >5 and < 30 min, AMS 

> 24 hours, PTA > 24 hours b

Type 1 TBI = most severe; Type 3 TBI = least severe (Barell Injury Matrix)