Strategies for Suicide Prevention

in Veterans

January 2009

Evidence-based Synthesis Program Department of Veterans Affairs

Health Services Research & Development Service

Prepared for: 

Department of Veterans Affairs

Veterans Health Administration

Health Services Research & Development Service

Washington, DC 20420 

Prepared by:

Greater Los Angeles Veterans Affairs Healthcare 

System/Southern California/RAND Evidence-based 

Practice Center 

Los Angeles, CA

Investigators

Paul Shekelle, MD, PhD

Director

Steven Bagley, MD, MS

Content Expert/Physician Reviewer

Brett Munjas, BA

Project Manager/Literature Database Manager
ii

Preface

VA’s Health Services Research and Development Service (HSR&D) works to improve the cost, 

quality, and outcomes of health care for our nation’s veterans. Collaborating with VA leaders, 

managers, and policy makers, HSR&D focuses on important health care topics that are likely 

to have significant impact on quality improvement efforts. One significant collaborative effort 

is HSR&D’s Evidence-based Synthesis Pilot Project (ESP). Through this project, HSR&D 

provides timely and accurate evidence syntheses on targeted health care topics. These products 

will be disseminated broadly throughout VA and will: inform VA clinical policy, develop clinical 

practice guidelines, set directions for future research to address gaps in knowledge, identify the 

evidence to support VA performance measures, and rationalize drug formulary decisions. 

HSR&D provided funding for the two Evidence Based Practice Centers (EPCs) supported by 

the Agency for Healthcare Research and Quality (AHRQ) that also had an active and publicly 

acknowledged VA affiliation—Southern California EPC and Portland, OR EPC—so they could 

develop evidence syntheses on requested topics for dissemination to VA policymakers. A 

planning committee with representation from HSR&D, Patient Care Services, Office of Quality 

and Performance, and the VISN Clinical Management Officers, has been established to identify 

priority topics and to insure the quality of final reports. 

Comments on this evidence report are welcome and can be sent to Susan Schiffner, ESP Program 

Manager, at Susan.Schiffner@va.gov.
iii

This report is based on research conducted by the Greater Los Angeles Veterans Affairs 

Healthcare System and Southern California Evidence-based Practice Center (EPC) under 

contract to the Department of Veterans Affairs. 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. 

Therefore, no statement in this article should be construed as an official position of the 

Department of Veterans Affairs.

This report is intended as a reference and not as a substitute for clinical judgment. 

This report may be used, in whole or in part, as the basis for development of clinical 

practice guidelines and other quality enhancement tools, or as a basis for reimbursement 

and coverage policies. The Department of Veterans Affairs endorsement of such 

derivative products may not be stated or implied.

Financial disclosure: No investigators have any affiliations or financial involvement 

(e.g., 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.
iv

Table of Contents 

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

Introduction.................................................................................................................................4

Background.....................................................................................................................................4

Methods ........................................................................................................................................8

Topic Development.........................................................................................................................8

Search Strategy ...............................................................................................................................8

Study Selection ...........................................................................................................................9

Data Abstraction ...........................................................................................................................10

Quality assessment of Individual Articles ....................................................................................10

Rating the body of evidence ........................................................................................................10

Peer Review ..................................................................................................................................12

Results ........................................................................................................................................13

Literature Flow .............................................................................................................................13

Key Question #1: What are the new or improved suicide prevention strategies (e.g. 

hotlines, outreach programs, peer counseling, treatment coordination programs, and new

counseling approaches) that show promise for Veterans?...................................................15

Key Question #2: What solid evidence base supports the most promising strategies? .....15

Key Question #3: What evidence is still needed to establish various strategies as the

most promising (framed as research questions to guide and focus continued research to

expand knowledge regarding the effectiveness of suicide prevention approaches)?........36

Summary and Discussion ............................................................................................................38

Limitations ...................................................................................................................................38

Conclusions...................................................................................................................................40

References..................................................................................................................................43

Table

Table 1. Set of Interventions from Mann et al ................................................................................8

Figures

Figure 1. Targets of Suicide Prevention Interventions from Mann et al.........................................7

Figure 2. Literature Flow..............................................................................................................16

Appendix

Appendix A. Data Collection Forms.............................................................................................50

Appendix B. Excluded Studies.....................................................................................................53

Appendix C. Evidence Tables.......................................................................................................68

Appendix D. Peer Review Comments..........................................................................................76
4

introduction

Background

Suicide is a major problem in public health. In the US suicide is roughly the 10th leading 

cause of death, corresponding to about 30,000 deaths per year. Suicide is now understood as 

a multifactorial phenomenon, with biological, psychological, and social/environmental risk 

vulnerabilities and triggers. The majority of suicides – at least 90% by some studies – in the US 

implicate a psychiatric disorder, usually a mood disorder.1,2

US military veterans are a large population with multiple, and often significant risk factors for 

suicide. The Veterans Health Study, which screened 2160 male outpatients at Boston-area VA 

clinics, reported depressive symptoms in 31% of the sample, a rate more than twice that of the 

general population.4

 A study of over 800,000 depressed veterans reported a suicide rate about 7 

times higher than the baseline risk in the general population.5

 The same study also showed that 

substance abuse elevated the suicide risk in depressed veterans. A recent report on the prevalence 

of mental health disorders in soldiers returning from the current Iraq conflict found clinicianidentified mental health problems in 20% of active duty personnel, and in over 40% of National 

Guard and reserve personnel.6

 Suicide in these newly discharged veterans has also received 

considerable political and media scrutiny.

The main problem confronting those working in suicide prevention is that while the absolute 

number of suicides in a population is cumulatively quite large, the risk of suicide to any given 

individual, even those with multiple risk factors, is by relative measures quite small. This 

problem is illustrated in an example in Gaynes et al.7

 who show that for reasonable assumptions 

of sensitivity and specificity, a screening test for suicide risk would have a positive predictive 

value of 0.3% and generate an overwhelming number of false positives. These same factors 

complicate any attempt at constructing randomized clinical trials of suicide prevention efforts. 

It is widely recognized that the problem of accurate suicide prediction at the clinical level is 

currently an intractable one.3

In spite of the difficulties with prediction, structured approaches to suicide prevention have been 

developed. The multifactorial nature of the problem of suicide has required the adoption of a 

multifaceted approach to intervention, combining population-based screening and education, 

with more targeted efforts for those at above-baseline risk. These methods were reviewed by 

Mann et al.1 and their conceptual model will organize the interventions we review in this report 

(Figure 1). 
5

Figure 1. Targets of Suicide Prevention Interventions from Mann et al.1

In their model life stressors and psychiatric disorders combine to produce suicidal ideation, 

which is modulated by impulsivity, hopelessness/pessimism, access to lethal means, and imitation, leading to the final suicidal act. The interventions correspond to different points in this 

causal network. The set of interventions, adapted from Mann et al., that are considered in this 

review appear in Table 1 and described in detail in the following.

Table 1. Set of interventions from Mann et al.1

Education and Awareness Programs

 Primary Care Physicians

 General Public/Population

Community or Organization Gatekeepers

Screening for individuals at high risk

Pharmacotherapy or ECT

Psychotherapy

Follow-up care for suicide attempts

Restriction of access to lethal means

Media reporting guidelines for suicide
6

Other Education and awareness programs can have various audiences; they can be aimed at 

primary care physicians to improve detection of mental health issues or significant stressors with 

the goal of referring to mental health clinicians for diagnosis and treatment, at a particular population (or the general public) to educate them about suicide and the availability of resources for 

getting help, and at nonclincian gatekeepers, such as medical clerks, chaplains, or military unit 

commanders, who as part of their work activities come into contact with large groups and who 

could, with improved training, provide education or identify those at high risk. 

Screening programs for those at high risk target interventions towards those with known risk 

factors for suicide. These include patients who have previously expressed suicidal ideation or 

made suicide attempts, or those with mood disorders or substance abuse disorders, who are 

higher risk than the general population.

Mental health treatment is typically organized into biological therapies, including both 

pharmacotherapy (e.g., antidepressants), and electroconvulsive therapy (ECT), and psychosocial 

approaches, such as psychotherapy (e.g., cognitive-behavioral therapy), supportive counseling or 

treatment for substance abuse.

Because suicide attempts are known to be a strong predictor of future attempts (and 

completions), specific invention efforts have been directed to this high-risk population. Typically 

this involves tracking individuals after emergency room visits for suicide attempts, providing 

close mental health follow up, therapy, or case management.

Restriction of access to lethal means covers a variety of population-wide measures that limit 

the availability of commonly used methods of suicide. These include restricting access to 

highly lethal means (firearms through background checks, waiting periods, licensing laws, or 

bans, jumping by installing barriers on bridges), common means (limiting package sizes or 

configurations of pharmaceuticals used in overdose, most commonly acetaminophen), and other 

community or social interventions (such as changing the source and composition of domestic gas 

to have a lower carbon monoxide content, and requiring the installation of catalytic converters on 

all newly manufactured vehicles to reduce the level of carbon monoxide in the exhaust gas). An 

important issue in means restriction is whether reducing the availability of one mechanism will 

reduce the suicide rate overall, or merely shift suicides towards other available methods.

Media reporting guidelines are designed to address the problem of imitation or contagion: widely 

publicized suicides, especially of celebrities, are thought to temporarily increase the suicide rate, 

especially of suicides that mimic the reported mechanism. More information about the media and 

imitative suicides can be found in a recent review by Pirkis.8

.

Suicide prevention programs, especially those designed for very large organizations such as 

military forces, or for entire nations, are typically multifaceted programs comprising a variety 

of different interventions just mentioned; most often the multifaceted programs combine 

population-based programs that use education and screening with more targeted interventions for 

those with identified risk factors.
7

Other factors not explicitly listed above, such as substance abuse, and homelessness, are also 

relevant because they affect impulsitivity or hopelessness, and are also obvious targets of both 

mental health and broader social interventions.

Because completed suicide is a very rare event in small samples, various approaches have been 

taken in assessing the efficacy of intervention programs. First, intermediate or proxy outcome 

measures can be used. Relevant outcomes would be decreases in depression rating scores, or 

decreased reports of suicidal ideation. However, the use of these measure greatly inflates the 

number of implicated studies for review – the examples mentioned would involve nearly all the 

published literature on the treatment of mood disorders – or involve subjective assessments of 

the strength of the suicidal ideation and whether the ideation was the precursor of an intended act 

or merely a means of communication to others or of obtaining hospital admission. Because of 

these concerns, the outcomes used in this report are suicide attempts, and completed suicides. 

In this report we review the state of the evidence for suicide prevention, with a special focus 

on the military and veteran populations. The interventions are organized into the taxonomy 

presented above. The three key questions were:

1. What are the new or improved suicide prevention strategies (e.g. hotlines, outreach 

programs, peer counseling, treatment coordination programs, and new counseling 

approaches) that show promise for Veterans?

2. What solid evidence base supports the most promising strategies?

3. What evidence is still needed to establish various strategies as the most promising 

(framed as research questions to guide and focus continued research to expand 

knowledge regarding the effectiveness of suicide prevention approaches)?
8

Methods

Topic Development

This project was nominated by the Office of Research and Development for the Evidence 

Synthesis Project. Key questions were discussed and finalized during a conference call that 

included the Steering Committee of the Evidence Synthesis Project and the VA Greater Los 

Angeles project site director. The final key questions are:

1. What are the new or improved suicide prevention strategies (e.g. hotlines, outreach 

programs, peer counseling, treatment coordination programs, and new counseling 

approaches) that show promise for Veterans?

2. What solid evidence base supports the most promising strategies?

3. What evidence is still needed to establish various strategies as the most promising 

(framed as research questions to guide and focus continued research to expand 

knowledge regarding the effectiveness of suicide prevention approaches)?

Search Strategy

Mann et al. completed a systematic review of the literature on suicide prevention from 1966 

through June 2005.1

 As we scored this article well on those aspects of the Oxman-Guyatt 

Overview Quality Assessment Questionnaire9

 and the AMSTAR Systematic Review Checklist10

that dealt with the rigor of the search and selection process, we judged the articles identified 

by this review as a suitable starting place for our own review. They searched MEDLINE, the 

Cochrane Library, and PsychINFO databases. We updated this using the same search strategy, 

starting from July 2005 through May 2008.

The search strategy is listed below:
9

DATABASES SEARCHED & TIME PERIOD COVERED:

PubMed

June 2005 – May 2008

LIMITERS: ENGLISH

SEARCH STRATEGY:

Suicide/prevention and control

OR

suicide, attempted/prevention and control

OR

suicide AND (prevent*[tiab] OR depression OR health education 

OR health promotion OR public opinion OR mass screening OR 

family physicians OR medical education OR primary health care 

OR antidepressive agents OR psychotherapy OR schools OR 

adolescents OR methods OR firearms OR overdose OR poisoning 

OR gas poisoning OR mass media)

NOT

case report* OR editorial* OR letter

TOTAL RESULTS – 3,212+

+

references to “suicide cells” & “suicide genes” were manually removed and are not included in 

this number

In addition to our PubMed search, we performed reference mining of retrieved articles, 

references of prior reviews, and solicited articles from experts.

Study Selection

In consultation with the ESP Advisory Committee and VA policymakers in mental health, we 

developed the following criteria to guide study selection. Our focus was on veterans and active 

military duty persons, consequently studies of children and adolescents were excluded. All 

studies of veterans and military personnel (from any country) were included. In addition to this, 

we included studies of the non-veteran population from the US and countries sufficiently similar 

to the US in terms of culture (Canada, United Kingdom, Ireland, Australia, New Zealand). Only 

studies that reported outcomes as suicides or suicide attempts were included; studies reporting 

only other proxy outcomes were excluded. Studies of strictly mental health interventions 

(psychotherapy, pharmacotherapy) have been reviewed by others and were therefore excluded 

unless they included military or veterans. 
10

Data Abstraction

Data were abstracted by a psychiatrist with prior experience in systematic reviews. The following 

data were abstracted from included trials: population, mean and median age, setting, country, 

interventions, outcomes, and study design. Data abstraction forms are provided in Appendix A.

Quality assessment OF INDIVIDUAL ARTICLES

To assess the quality of the RCT and CCTs we used was a modification of the Delphi List.11 We 

abstracted data on whether or not the study was described as randomized; treatment allocation; 

was the method of randomization performed and was the treatment allocation concealed; were 

the groups similar at baseline regarding the most important prognostic indicators; were the 

eligibility criteria specified; was the outcome assessor blinded; was the care provider blinded; 

was the patient blinded; were point estimates and measures of variability presented for the 

primary outcome measures; were all randomized participants analyzed in the group to which 

they were allocated; were co-interventions avoided or similar; was compliance in all groups 

acceptable; was the timing of the outcome assessment in all groups similar.

Rating the body of evidence 

We assessed the overall quality of evidence for outcomes using a method developed by the 

Grade Working Group, which classified the grade of evidence across outcomes according to the 

following criteria:12

•	 High = Further research is very unlikely to change our confidence on the estimate of 

effect.

•	 Moderate = Further research is likely to have an important impact on our confidence 

in the estimate of effect and may change the estimate.

•	 Low = Further research is very likely to have an important impact on our confidence in 

the estimate of effect and is likely to change the estimate. 

•	 Very Low = Any estimate of effect is very uncertain. 
11

GRADE also suggests using the following scheme for assigning the “grade” or strength of 

evidence:

Criteria for assigning grade of evidence

Type of evidence

Randomized trial = high

Observational study = low

Any other evidence = very low

Decrease grade if:

•	 Serious (-1) or very serious (-2) limitation to study quality

•	 Important inconsistency (-1)

•	 Some (-1) or major (-2) uncertainty about directness

•	 Imprecise or sparse data (-1)

•	 High probability of reporting bias (-1)

Increase grade if:

•	 Strong evidence of association-significant relative risk of > 2 (< 0.5) 

based on consistent evidence from two or more observational studies, 

with no plausible confounders (+1)

•	 Very strong evidence of association-significant relative risk of > 5 

(< 0.2) based on direct evidence with no major threats to validity (+2)

•	 Evidence of a dose response gradient (+1)

•	 All plausible confounders would have reduced the effect (+1)

For this report, we used both this explicit scoring scheme and the global implicit judgment 

about “confidence” in the result. Where the two disagreed, we went with the lower of the two 

classifications.

Data Synthesis

The studies included in this review were too heterogeneous to statistically pool, and we therefore 

summarized these narratively, in the following categories multifaceted interventions for military 

personnel; other multifaceted programs (national suicide prevention programs); interventions 

for veterans; psychosocial interventions post-suicide attempt; postal or telephone follow up 

post-suicide attempt; hospital admission for attempted suicide; and restriction of access to lethal 

means.
12

Peer Review

This report was reviewed by 6 experts selected by the VA ESP Advisory Committee for their 

expertise in this area and their knowledge of VA. Peer review comments received, and the 

changes we made to the report as a result, are presented in Appendix D.
13

Results

Literature Flow – UPDATE

In total, we examined 3,406 titles. The electronic literature search identified 3,212 articles. An 

additional 196 articles were identified through reference mining. A content expert identified 5 

more articles. 

Of the titles identified through our electronic literature search, 3,140 were rejected at title review 

as clearly irrelevant to the project. This left 273 from all sources. Seven articles were rejected as 

not relevant. Five titles could not be located after contacting many sources. (Figure 2)

We reviewed a total of 261 articles. Initial screening of the articles resulted in three articles that 

included veterans and seven articles that included military personnel. We excluded 135 article 

for the following reasons: five because they did not include an intervention, two foreign language 

articles, three articles contained duplicate data, 41 review or meta-analyses, 82 articles with no 

outcome of interest or no usable data, one study of adolescents only, and one editorial. This left 

126 articles included for further review.

Following guidance from the ESP Advisory Committee in our further inclusion criteria we 

excluded an additional 49 studies. Studies were excluded for studies conducted in countries 

other than US, Canada, United Kingdom, Ireland, Australia, or New Zealand and not containing 

military personnel or veterans; only reporting suicidal ideations, or being a strictly psychotherapy 

or pharmacotherapy study. Of studies that met our inclusion criteria we found 20 RCT or CCT 

studies, 28 observational studies, 6 cohort studies, and 23 interrupted time series studies.

Excluded articles and reasons for exclusion are listed in Appendix B. 

The results have been grouped together by the kind of intervention, and within that, by study 

design. We first report on studies of military or veterans that use multifaceted (multi-component) 

interventions. This includes all the studies (of any type) that directly studied military personnel. 

For comparison, we then present other multifaceted interventions, both of which are national 

suicide prevention programs. We then report on several other interventions identified that 

included veterans.
14

Figure 2. Literature Flow

 

 

*Studies excluded for multiple reasons

Total number of titles identified from literature search

n= 3,212

3,140 excluded at title review

Literature search

n= 72

Content expert

n= 5

Reference mining

n= 196

Total number of titles considered possibly relevant and articles ordered

n= 266

Articles rejected: 

Not relevant n= 7

Articles not found

n= 5

Total number of articles reviewed 

n= 261

Excluded

No Intervention: n=5

Foreign Language: n=2

Duplicate Data: n=3

Review or Meta-analysis: n=41

No Outcome of Interest or Usable Outcome: n=82

Adolescent: n=1

Design – Other: n=1

Articles included

n= 126 

Excluded (n=49)*

Country - Other n=28

Pharmacotherapy n=7

Psychotherapy n=17

Suicidal Ideation Only n=4

Articles included for detailed review **

n= 77

Cohort 

n=6

RCT/CCT

n=20

Observational 

n=28

Interrupted Time 

Series

n=23
15

Key Question #1: What are the new or improved suicide 

prevention strategies (e.g. hotlines, outreach programs, peer 

counseling, treatment coordination programs, and new counseling approaches) that show promise for Veterans?

Key Question #2: What solid evidence base supports the 

most promising strategies?

OVERVIEW

This results section is organized by the target and the method of the intervention, first with 

studies of multifaceted interventions. We found studies of multifaceted interventions only 

for military personnel or the general population. We did not find any studies of multifaceted 

interventions for veterans. Following the review of multifaceted interventions is a review of 

the studies that did include veterans. The report then discusses evidence from other populations 

using interventions post-suicide attempt, suicide prevention centers, hospital admission for 

attempted suicide, collaborative care for depression, and an intervention for the identified 

patient’s support network. Then observational studies for restricting access to lethal means 

(firearms, acetaminophen, other toxic agents, and bridge barriers), and restrictions of media 

reporting of suicides are presented. 

Multifaceted interventions for military personnel

Seven studies involving military personnel were identified. All were prospective cohort studies 

in which the intervention was implemented for the entire population. The characteristics, 

interventions, and outcomes of the military studies are shown in Evidence Table 1 in Appendix 

C.

James and Kowalski13 described a suicide prevention program for the US Army 25th Infantry 

Division (Light) that was started in 1992 and fully implemented by early 1994. Psychological 

autopsy data from 1985 to 1993 identified various risk factors in this population including 

demographics (all male), mental status (depression), substance abuse, and relationship problems 

(all the suicides involved marital or relationship discord or alleged infidelity). The intervention 

reported was multifactorial and multidisciplinary. The disciplines involved included the 

chaplain (to provide individual counseling and division-wide education), the psychologist (to 

coordinate training, and assist in identifying high-risk soldiers), the social worker (to provide 

a liaison for the soldier, their family, and the soldier’s commander). Specific components of 

the intervention as reported included: lectures by chaplains, lectures at training programs (for 

division commanders and enlisted soldiers), pocket-sized cards with warning signs and contact 

information for emergency services, “crisis-intervention command consultations” (special 

meetings with soldier, their commanders, and division mental health officer), a “high-risk book” 

(once identified as high risk, the soldier’s commander provide bi-monthly written assessments 

on the soldier’s progress), outpatient follow up care with mental health services, and mental 
16

health services for the soldier and their family, along with a substance abuse prevention program. 

The size of the study population was not reported. The program was not formally evaluated, but 

in a postscript the authors noted, “the suicide rate has decreased to three in the past 2 years.” 

Unfortunately, the baseline comparison rate was not clearly reported, so we cannot reach any 

conclusions about effectiveness.

McDaniel et al.14 reported on a suicide prevention program at a US Navy Training Command 

that was implemented after a cluster of suicides in 1986. The target of the intervention was 

the petty officers and chief petty officers who were the instructors at the command. They were 

educated to recognize risk factors likely to be common in the students of the training command 

(recent interpersonal losses, substance abuse, social isolation, and personality disorders and 

psychiatric illnesses), and about the goals of fostering group cohesiveness and ensuring treatment 

compliance for those referred for treatment. The size of the study population was not reported. 

The main outcome assessed was suicide attempts at the training command in comparison with 

that reported at a similarly sized operational command nearby. They reported a statistically 

significant negative correlation between the number of instructors trained and the number of 

suicide attempts. They concluded that the program reduced the number of suicide attempts at the 

training command. However, there were a number of complicating factors, including seasonal 

factors stemming for start dates for cohorts of students at the training command and limited of 

hours of operation when potentially suicidal students were referred to the operational command 

for evaluation (thus inflating the number of suicide attempts reported at the latter facility). 

Knox et al.15 described a multifactorial suicide prevention program implemented in the US 

Air Force, comprising over 5,000,000 active duty personnel. The intervention was designed to 

reduce stigma and risk factors, and strengthen protective factors in a population-based approach. 

The program had 11 components. There was training for squadron commanders, addition of 

suicide prevention into required training, use of guidelines for mental health referral, addition 

of staff to support community-based preventive services at mental health centers, and required 

training for non-professionals in suicide risks and referral procedures. The program also assessed 

for suicide risk those under investigation for legal problems, established teams to respond to 

traumatic events including suicides, integrated the delivery system for human services prevention 

activities, established patient privilege in psychotherapy, conducted a behavior health survey, and 

established a suicide event surveillance system for tracking risk factors. To evaluate the program, 

the USAF population from 1990-6 was the control cohort, and the 1997-2002 population was 

the treatment cohort. No differences in demographic characteristics or in rates for mental health 

disability were found between the two groups. There was a statistically significant trend for 

decline in suicide rate over time, with a 33% reduction of risk for completed suicide compared to 

the baseline rate. The average rate in the pre-intervention period was 13.5 per 100,000, and 9.2 in 

the post-intervention period.

Jones et al.16 described a US Navy and Marine Corps initiative to reducing suicide using “best 

practice strategies.” They identified existing resources relevant to suicide prevention, which 

included awareness (education about suicide prevention for all personnel and in leadership 

schools), life skills training (for substance abuse, stress and anger management, conflict 

resolution), post-suicide attempt interventions (family support, critical event stress debriefing), 
17

and data collection (suicide incident reports with explicit monitoring and tracking of data). A 

training video on suicide prevention was developed for all personnel; it highlighted positive role 

models and early identification of those at risk by co-workers, and was included as part of the 

required annual General Military Training (GMT) starting in the summer of 2000. The size of the 

study population was not reported. The authors reported that, “the introduction of annual suicide 

prevention GMT requirement coincided with a drop in Navy suicide rate for FY-01 to 9.2/100K. 

This is the lowest rate in 10 years.” The Marine Corps rate for the same year was 15.6/100,000, 

but no baseline rate or comparison was provided.

Kennedy et al.17 described an overseas gambling treatment program for the US Navy. 

Pathological gambling was recognized to have significant psychiatric comorbidity, including 

substance abuse, mood disorders, and suicidality. The program focused on overseas gambling 

because of the relative lack of restriction on slot machines in military clubs overseas, and the 

lack of overseas treatment options for pathological gambling. The services were provided at a 

naval base in Okinawa, Japan within the context of a substance abuse rehabilitation program, 

and included psychological evaluation, individual and group counseling, patient and family 

education, Gambler’s Anonymous, and access to a gambling crisis counseling around the 

clock. The program was evaluated for a year (roughly, the calendar year 2004) during which 35 

individuals were referred. Twenty percent of those reported suicidal ideation, and 3 had made 

gambling-related suicide attempts before referral. During the treatment period, there were no 

attempted suicides and no suicidal ideation recurred. 

Two suicide military-based suicide prevention programs outside the US have been reported. 

Rozanov et al.18 described a program implemented in a military unit of size 10,000 in the 

Ukrainian Army. The program set up training seminars about suicide, risk factors, and prevention 

for commanders, officers, and basic soldiers. Training booklets were also distributed. The suicide 

rates in the years 1988-1999 (pre-implementation) were compared to the rates in 2000 and 2001. 

The total suicide rate over all military personnel in the pre-implementation period was 32.6 per 

100,000. The rate for 2000 was 0 and 16.7 for 2001.

Gordana and Milivoje19 reported on a suicide prevention program in the Army of Serbia and 

Montenegro, influenced by the USAF program of Knox,15 above. The program components 

included selection (to remove recruits with serious mental problems), education about 

suicide risk factors, and motivation for military duty. Training was provided to soldiers about 

maladjustment and substance abuse. Unit and central command physicians, psychologists, and 

officers were also involved. The program was fully implemented in December 2003. The size 

of the study population was not reported. The annual suicide rate for the Yugoslav Army for the 

years 1999 to 2003 was 13 per 100,000, declining in the post-implementation period to 5 per 

100,000 in 2004. 

In summary, seven studies of suicide prevention for military personnel were identified. All used 

a conceptual model of risk factor identification, based on review of suicides in the population 

under study, augmented with factors previously identified by others, followed by educational 

and organizational changes to reduce those factors or increase education and awareness about 

them. All were multifaceted programs, and all reported declines in suicides or suicide attempts. 
18

However, the reporting of sufficient data to make proper comparison was incomplete, and the 

quality of the analysis that was reported was generally poor. The largest studies were deployed 

for the US Navy and Marine Corps and for the US Air Force. The clearly methodologically 

strongest study was that of Knox et al.15 for the US Air Force, which also appears to have 

influenced other studies. However, much more data are needed in order to better understand 

what are the most effective components to include in a multicomponent intervention, and how 

each component can be both internally optimized and made most synergistic with the other 

components. 

Other multifaceted programs (national suicide prevention programs)

Two studies reporting results of multicomponent national suicide prevention programs were 

identified, one for Australia, and one for England. Both were prospective, cohort designs.

Robinson et al.20 published a commentary on Australia’s National Suicide Prevention Strategy. 

They divided the interventions in the NSPS into universal (targeting populations), selective 

(groups with risk factors), and indicated (for groups that have already displayed some suicidal 

thoughts or behaviors). Most of the interventions were universal interventions aimed at young 

people or minorities. They noted that neither those with mental illness nor those with previous 

suicide attempts had been the targets of any of the national initiatives. During the interval of the 

program’s existence, 1999 to 2004, the suicide rate dropped from 22 to 17 for men, and 5 to 4 for 

women, both measured per 100,000. As they note, this decline “cannot necessarily be attributed 

to the NSPS.”

In 2002, England started a national suicide prevention program, the status of which has been 

documented in a series of yearly updates, the latest of which covers through year 2006.21

Their multifaceted program includes mental health (focus on post-hospital discharge and noncompliance with treatment), study of self-harm as a risk for suicide, mental health promotion 

projects for young men and for those in the prison system. Their program also includes efforts to 

reduce access to lethal means (removing points for hanging on psychiatric wards, and a phased 

withdrawal of co-proxamol, a painkiller lethal in overdose), and establishment of systems to 

conduct suicide audits through Primary Care Trusts. The program set a target of a 20% reduction 

in suicides during the implementation period. Using age-standardized rates, the rate for 2003-5 

was compared the baseline rate for 1995-7. The post-intervention rate was 8.5 deaths per 

100,000, which represented at 7.4% decrease from the baseline rate.

In summary, two national suicide prevention programs reported declines in suicide rates 

coincident with the introduction of those programs. Both published reports provided scant details 

on methodology.

Interventions for veterans

Three reports involving US veterans were identified. This is a heterogeneous set. One was an 

RCT using psychotherapy for female veterans with borderline personality disorder. One study 
19

looked at the association between treatment in a residential program for substance abuse and 

suicide attempts. One study examined the association between treatment with antidepressant 

medication and the development of suicidal ideation. (Evidence tables for RCT/CCTs in this 

section and subsequent sections are shown in Evidence Table 2, which includes the quality 

assessment ratings; all Military/Veteran Studies are shown in Evidence Table 1)

Koons et al.22 reported a pilot RCT of dialectical behavior therapy for female veterans with 

borderline personality disorder. Patients with the appropriate diagnosis were recruited through 

clinics at the Durham VA and other VA clinics in North Carolina. The treatment group received 

dialectical behavior therapy, a kind of psychotherapy explicitly designed to treat patients with 

chronic suicidality or self-injurious behaviors. It includes both individual and group therapy, 

and separate consultation sessions for the therapists, all conducted weekly. The treatment lasted 

6 months. The control group received weekly individual therapy. The assessed outcome was 

intentional self-harm (including suicide attempts) in the preceding 3 months. In the treatment 

group this decreased from 50% to 10% (at 6 months), and in the control group decreased from 

30% to 20%. This decrease was not statistically significant, possibly due to the small sample size 

(10 patients completed in each group).

Ilgen23 studied US veterans entering substance abuse treatment programs (either residential 

or outpatient), and compared the suicide attempt rate in the previous 12 months at program 

entry, during treatment, and in the 12 month follow-up interval. The median treatment duration 

was 12 months. A total of 3733 patients were followed. In predicting suicide attempts during 

treatment, residential treatment was associated with a lower rate than outpatient treatment, even 

when baseline suicidality was controlled for. In predicting suicide attempts after treatment, none 

of treatment setting (residential vs. outpatient), availability of psychiatric services, and use of 

psychiatric services was statistically significant, although longer treatment episode was.

Gibbons et al.24 examined the hypothesized association between treatment with antidepressants 

and the development of suicidal ideation and behavior; earlier studies had led to the FDA’s black 

box warning for children, adolescents, and young adults for these medications. The authors 

studied administrative and pharmacy data from the Veteran Health Administration with data on 

over 226000 patients to identify those patients with new depressive disorders (no history in the 

prior two years). The outcome variable was suicide attempts treated at VA facilities. Cause of 

death information was not available for completed suicides. When compared to those depressed 

patients not receiving an antidepressant, there were reductions in the suicide rate for each class 

(SSRI monotherapy, non-SSRI monotherapy, and tricyclic monotherapy) studies. When suicide 

attempt rates were compared within in each class of treatment, the relative risk (in treatment vs. 

before treatment) was reduced with treatment.

In summary, three studies involving US veterans. One RCT found a trend not reaching statistical 

significant for the use of dialectical behavior therapy for female veterans with borderline personality 

disorder. One reported mixed results looking at associations between residential treatment of 

substance abuse and suicide attempts. One reported reduction in suicide rates associated with 

treatment with antidepressants. Because of the study designs, it was not possible to infer causality 

from the reported associations, and the heterogeneity of these studies limits any generalization.
20

Psychosocial interventions post-suicide attempt

Twelve studies were found that described case management or therapeutic interventions initiated 

after presentations for suicide attempts. These studies are presented here by country, and then 

chronologically. 

Psychosocial interventions post-suicide attempt, USA

Welu25 described a program implemented for those making a suicide attempt seen in the 

emergency room of a hospital in Pittsburgh, Pennsylvania. Patients in the treatment group were 

seen in a special outreach program staffed by registered nurses, social workers, and community 

workers. Patients were contacted as soon as possible after release from the hospital to set up 

home visits. Subsequently mental health treatment designed to meet the needs of that particular 

patient were made available. Patients were in contact with staff at least biweekly to provide 

treatment, or to monitor the treatment when it was provided by other services. Patients assigned 

to the control group were treated in the usual manner in the ER or hospital, and released with 

written appointments; no attempts were made to provide outreach to those who failed to follow 

up. Patients were randomized to the treatment or control group. Both groups were contacted for 

an interview 4 months after the suicide attempt for assessment. The outcome was the number of 

suicide reattempts in the 4 month follow up period. The treatment group had 4.8% reattempt rate, 

while the control group had a 15.8% reattempt rate, a statistically significant difference.

Psychosocial interventions post-suicide attempt, Canada

Termansen and Bywater26 described a project implemented at Vancouver General Hospital for all 

patients presenting to that emergency room for a suicide attempt during a three month period in 

1972. Patients were allocated to one of four treatment groups on a rotating (nonrandom) basis. 

The first group was assessed in the ER and followed for three months for the same (lay) mental 

health worker. The second group was assessed in the ER by a mental health worker, but followed 

by a crisis center volunteer for three months and then assessed by that volunteer and a mental 

health worker. The third group received the ER assessment by the mental health worked but with 

no follow up other than assessment at three months. The fourth group was identified on the basis 

of ER records, received no other intervention, and was assessed at three months by a mental 

health worker. The follow up provided to the first two groups was either in-person or by phone 

on a schedule of decreasing frequency from daily for the first week down to every other week for 

weeks 9 through 12. They reported the number of suicide attempts in each group: Group 1 had 

1/45 (2.2%), Group 2 had 2/33 (6.1%), Group 3 had 7/32 (22%), and Group 4 had 2/18 (11.1%). 

The lower rate for Group 1 was statistically significant.

Allard et al.27 reported on a follow-up program used in several Montreal hospitals after a 

suicide attempt. The treatment group received an intensive intervention program consisting of 

an explicit treatment plan, a schedule of visits for a year, at least one home visit from a social 

worker, appointment reminders by phone or in writing or home visits for missed appointments, 

and referral for normal psychiatric treatment at the end of the one-year program. Specific 

mental health treatment was left to the therapist and could include biologic or psychotherapeutic 
21

treatment. The control group received normal care at the hospital. Patients were randomized to 

the treatment or control group. The outcome assessed was the recurrence of suicide attempts in 

the two years following the index attempt. They found a recurrence rate of 35% in the treatment 

group, and 30% in the control group, a statistically insignificant difference. There were three 

suicide completions in the treatment group and one in the control group.

Psychosocial interventions post-suicide attempt, UK

Chowdhury et al.28 described an experimental program at the Regional Poisoning Treatment 

Centre in Edinburgh, Scotland, for those making repeated suicide attempts, defined as those with 

a history of one or more prior admissions to that facility within the previous three years. The 

treatment was a new service staffed by mental health clinicians that offered follow up care in 

local clinics (either scheduled, or in a walk-in basis), with home visits for all those patients who 

did not keep scheduled appointments. Arrangements were also made so that patients calling a 

local suicide hotline would be called by staff, scheduled for an appointment, or seen at home by 

the service staff. Eligible patients were alternately (not randomly) assigned to either the treatment 

group or the control group, the latter group receiving the usual treatment of being scheduled 

with a mental health clinician, but with no attempts to pursue those who failed to keep the 

appointment. An exception was made for those patients judged to be at high risk of suicide; these 

patients were automatically assigned to the treatment service, but excluded from the treatment 

group for comparison in the analysis. The reported outcome was the number of suicide attempts 

in a six-month follow up period. They found that 24% of the treatment group patients and 23% of 

the control group patients had one or more suicide attempts, a statistically insignificant difference 

by the chi-squared test. There were no completed suicides in either group.

Gardner et al.29 reported on a suicide-attempt evaluation program implemented at a hospital 

in Cambridge, England. All patients admitted for a self-poisoning were randomly assigned for 

assessment to either a medical team (including a social worker) or a psychiatrist. The medical 

team members received some (unspecified) instruction in psychiatric evaluation. The purpose 

of the assessment was to determine whether further inpatient or outpatient psychiatric care was 

needed. Patients were followed for one year after their attempt. Patient who re-presented at 

the hospital with subsequent attempts were reentered into the study and re-randomized to an 

intervention; these patients were thus counted more than once. The outcomes assessed were 

reattempts or completions. Survival curves for the proportion of admissions without relapse 

(reattempt) were constructed, and showed a slight but not statistically significant trend for less 

relapse for those patients assigned to the medical team. A similar result was found when using 

only first-admission data for each patient. There were no suicides in the medical team group and 

one suicide in the psychiatrist group. 

Gibbons et al.30 reported on a post-suicide social work intervention program at Southampton 

General Hospital, England. The treatment was a “task-centered casework” approach, in which 

specific problems in social roles, transitions, or resources were identified, and set out as tasks 

that the social worker helped the client complete. These services were provided in the patients’ 

homes. Patient who presented to the hospital Accident and Emergency Department (ER) with 

deliberate self-poisonings were randomly assigned to either the treatment or the control group of 
22

routine treatment (referral back to General Practitioner or to psychiatry). The outcome assessed 

was the number of recurrences of self-poisoning in the 12 months after the index attempt. The 

treatment group had 13.5% recurrence rate, while the control group had a 14.5% recurrence rate, 

a statistically insignificant difference.

Hawton et al.31 reported on a domiciliary (home-based) treatment program for patients admitted 

to the General Hospital in Oxford, England for deliberate self-poisoning. A special service for 

such patients was developed using nursing and social work staff, using a problem-oriented crisis 

intervention approach. In this study the treatment group received these services at home as often 

as the therapists felt necessary. The control group received the same services provided weekly 

in clinic. Treatment in both groups lasted up to 3 months. Patients were randomly assigned to 

either the treatment or control group. The outcome measure was the rate of repetition of suicide 

attempt. They found the domiciliary group had a repetition rate of 10%, and the out-patient group 

a rate of 15% in the year following the index overdose. This difference was not statistically 

significant.

Hawton et al.32 described a program comparing out-patient counseling with referral to General 

Practitioner care for patients admitted to the General Hospital in Oxford, England for deliberate 

self-poisoning. The treatment group was given out-patient counseling using a problem-oriented 

approach by the clinician who conducted the initial assessment. The meaning of the attempt 

was explored, and alternative coping mechanisms were identified. In the control group patients 

were referred back to their GPs with recommendations for further care, such as marital therapy. 

Patients were randomized to the treatment or control group. The outcome assessed was the 

rate of repeated suicide attempt at one year post-attempt. The treatment group had a 15.4% 

repeat rate, while the control group had a 7.3% repeat rate; this difference was not statistically 

significant. There was one completed suicide in the out-patient counseling group; “she had 

attended OP counseling sessions, but before the end of treatment moved to another area where 

she was referred to psychiatric care, and where her death occurred.”

Guthrie et al.33 reported on a brief psychological intervention after deliberate self-poisoning 

implemented at a hospital in Manchester, England. The treatment consisted of four sessions of 

psychodynamic interpersonal therapy, starting within a week of presentation at the hospital’s 

emergency department. The therapy was given by a nurse in the patient’s home. The control 

group was given routine care, which involved assessment in the ER and referral to psychiatry, 

addiction services, or their general practitioner. Patients were randomized to the treatment or 

control group. The outcome assessed was further episodes of self-harm within a six-month 

period. The treatment group had a 9% repeat rate, while the control group had a 28% repeat rate, 

a statistically significant decrease. There were no completed suicides in either group.

Bennewith et al.34 conducted a cluster randomized controlled trial of a general practice-based 

intervention in a region of England. For practices include in the treatment group, new episodes of 

self-harm in patients of those practices were identified. If the episode was the first for that patient 

during the trial period, the patient’s general practitioner was sent a letter informing them of the 

incident, along with another letter to forward to the patient inviting the patient to schedule an 

appointment, and a copy of treatment guidelines for the management of self harm to be placed in 
23

the patient’s chart and used during their appointment. The control group received normal referral 

services. GP practices were randomized to the treatment or control group. The outcome assessed 

was the recurrence of an episode of deliberate self-harm in the 12 months after the index episode. 

The treatment group had a recurrence rate of 21.9%, while the control group had a recurrence 

rate of 19.5%; this difference was not statistically significant. Time to the repeat episode and the 

number of repeat episodes were also not statistically significantly different.

Clarke et al.35 reported on an intervention for deliberate self-harm, implemented at two Accident 

& Emergency (ER) departments on the London/Essex border in England. The intervention 

group received case management services from a nurse practitioner who conducted an initial 

assessment, constructed a care plan, and was available on a ‘open access’ basis by mobile phone; 

the NP coordinated access to care but did not provide the services themselves. The intervention 

group also received the routine care provided to the control group, which comprised triage 

services and medical and psychiatric treatment as needed. Patients were randomized to the 

treatment or control group. The outcome assessed was the readmission rate for recurrent selfharm. In the 12 months following the index episode, the treatment group had a 9% readmission 

rate, while the control group had a 10% readmission rate; this difference was not statistically 

significant. A statistically significant greater number of patients requiring multiple readmissions 

were in the treatment group.

Psychosocial interventions post-suicide attempt, Australia

Aoun36 described a non-randomized intervention in a region of Western Australia. All patients 

presenting at one particular hospital or to community clinics after a suicide attempt or who were 

judged to be at risk of self-harm were offered the intervention. The intervention consisted of a 

suicide intervention counselor who provided crisis management and coordination of follow-up 

out to 6 weeks from first contact. Patients could be referred to GPs, other health professionals 

and agencies. The hospital also enhanced assessment and treatment while in the hospital, and the 

suicide intervention counselor provided education about risk assessment and treatment resources 

to health professionals and the community. A 2 year pre-intervention retrospective chart review 

was conducted to establish the baseline outcomes. Information on the program was collected 

for 22 months starting in November 1995. The outcome assessed with the number of suicide 

attempts leading to readmission. Those in the treatment group had a reattempt rate of 3.6%, 

while those in the standard treatment group had a reattempt rate of 12.6%; this was statistically 

significant. The pre-intervention rate in the preceding 22 months was 11.1%; this was statistically 

significant when compared to the treatment group rate. The author did note that during the 

treatment period the total number of hospital admissions increased; this appears to have been in 

part driven by a policy to hospitalize for assessment and treatment.

In summary, 12 studies, nearly all randomized or controlled clinical trials, reporting psychosocial 

interventions post-suicide attempt were identified. Interventions varied, but mostly consisted 

of additional resources, such as case management to monitor patients, and facilitate access 

to mental health services. Most studies did not report any statistically significant differences 

between treatment and control, and in many the proportion of repeat attempts were within a 
24

few percent of other. In other studies the average difference was 5%-8% indicating a signal of 

potential efficacy that possibly could be detected with a larger sample size. The four studies 

reporting statistically significant results did not differ in any marked way from the nonsignificant 

studies in terms of patients studied, interventions, or study quality. However, a wide range in 

suicide attempt rates across studies was noted. The efficacy of these programs does not appear 

to be robust, and it remains what program characteristics led to the positive results in those four 

studies, and indeed unclear whether psychosocial interventions aimed at suicide attempters 

reduce repeated attempts.

Postal or telephone follow up post-suicide attempt

Four studies reporting on telephone or postal follow up after suicide attempts were identified. 

They are presented by country and then by date.

Postal or telephone follow up post-suicide attempt, USA

Motto and Bostrom37 described a program in San Francisco for patients admitted to a psychiatric 

hospital for depression or “suicidal state.” All patients were offered post-discharge therapy. All 

patients who declined such treatment or discontinued within 30 days were then randomized 

to either the contact group or the no-contact group. Patients in the contact group received 

short, personalized letters from the research staff who had conducted their initial interviews 

expressing concern about the patient, and inviting the patient to respond if they desired. No 

specific recommendations or treatments were made in the letters. Letters were sent monthly for 

four months, every two months for eight months, and every three months for four years for a 

total of 24 contacts over 5 years. Patients in the no-contact group and those who had complied 

with the initial post-discharge therapy received no letters. The outcome assessed was completed 

suicides. In five years after the index contact, the treatment (contact) group had a suicide rate of 

3.9% compared to the control (no-contact) group at 4.6%. These rates at 15 years were 6.4% for 

treatment and 5.7% for control. A survival analysis showed statistically significant differences for 

the first two years, but not later. They concluded that the results were consistent with their study 

hypothesis: that the period of maximum contact, especially the first year, would have the greater 

divergence in suicide rate.

Postal or telephone follow up post-suicide attempt, UK

Morgan et al.38 reported an intervention to provide patients seen in the Accident and Emergency 

(ER) department for first episodes of deliberate self-harm with easy access by phone to on-call 

trainee psychiatrists. This study was conducted in the United Bristol Healthcare Trust catchment 

area in England. Specifically, those in the treatment group were provided a ‘green card’ which 

stated that a doctor was available at all times by telephone, and also encouraged patients to seek 

care by phone or in person at the ER. Those assigned to the treatment group received another 

copy of the card by mail at their home address three weeks after the index episode. Their GPs 

were also sent a copy of the card and asked to discuss it with the patients as appropriate. The 

control group received routine care. Patients were randomized to the treatment or control group. 
25

The outcome assessed was the repetition of deliberate self-harm. There were 7 repeats in the 

treatment group, and 15 repeats in the control group. No completed suicides occurred in either 

group. Measures of statistical significance were not reported.

Evans et al.39 repeated the study of Morgan et al.38 with the same intervention, modified to 

allow patients with previous episodes of self-harm, and providing them only phone contact 

without offers of in-person assessment or hospital admission. Patients were again randomized 

to the treatment or control group. The rate of repetition of deliberate self-harm in the treatment 

group was 16.8% compared to 14.4% in the control group. This difference was not statistically 

significant. There were two completed suicides in the treatment group and one suicide in the 

control group. They noted that “neither of the suicides from the green card group had made use 

of the green card at any time to seek help.”

Postal or telephone follow up post-suicide attempt, Australia

Carter et al.40 implemented a postcard-based intervention, based on the Motto and Bostrom37

study, for those patients with deliberate self-poisoning presenting at regional toxicology unit 

in New South Wales, Australia. The intervention consisted of a postcard sent to the patient in a 

sealed envelope at 1, 2, 3,4, 6, 8, 10, and 12 months post-discharge. The card wished the patient 

well and invited a response if they were interested. The control treatment was not described. 

Patients were randomized to the treatment or control group. The outcome assessed was repetition 

of deliberate self-poisoning. The treatment group had 15.1% with one or more repeat episodes, 

while the control group had 17.3%; this difference was not statistically significant. The number 

of repeat episodes in the treatment group was about one half of that in the control group; this was 

statistically significant.

In summary, four studies of low-intensity post-suicide attempt interventions by phone or mail 

were identified. The results in the larger studies were either not statistically significant or were of 

modest efficacy. 

Community-based Suicide Prevention Centers

Three observational studies about community-based suicide prevention centers were identified.

Walk41 reported on a “Community Care” service implemented in Chichester, England, starting 

in 1958. The service was described as “with its blurred distinctions between in-patient, daypatient, out-patient and domiciliary treatment, its ready availability and its better contact with 

the community.” (Unfortunately, no further details about the program were provided.) The 

suicide rate in five year periods before and after the program was started were compared. Their 

conclusion was “the introduction of Community Care may have protected some elderly patients 

from suicide, whereas it has had no clear effect on suicide among younger patients.”

Bagley42 examined data concerning the introduction of the Samaritan Suicide Prevention 

Schemes in 15 British towns. This program provides a suicide telephone hotline, available day or 
26

night. The hotline was staffed by clergy or lay workers who had undergone training designed to 

provide the workers with the skills to determine if the caller needed referral to clinical services. 

Each town in which the scheme was implemented was compared to a control town that matched 

on socioeconomic measures. The outcome assessed was the suicide rate in the same number of 

years before and after the program started, the actual number determined by the availability of 

data and ranged from 2 to 4 years. The average rate (per 100,000) for the treatment group towns 

was 13.03, decreasing to 12.27 after, and the average rate for the control towns was 12.56 before, 

increasing to 15.05 after. These changes were found to be statistically significant by a variety of 

measures. 

Barraclough et al.43 examined the same data using four different methods of choosing the control 

towns, including variations on the method of Bagley, matching on the pre-implementation 

suicide rate, or on the proportion of single-person households. They looked at suicide rates 

over three year pre- and post-implementation windows. They found no statistically significant 

difference in the suicide rates.

In summary, three studies of suicide-prevention centers were identified. One reported on an early, 

and very poorly described community-based program in England. Two examined the effect of the 

Samaritan Suicide Prevention Scheme in England and reached opposite conclusions. Overall the 

quality of these studies was low and the results inconclusive.

Hospital admission for attempted suicide

One RCT using hospital admission as the intervention for attempted suicide was identified.

Waterhouse and Platt44 conducted their trial at the York District Hospital in England. Junior 

doctors were trained in the assessment of suicide attempts. Patients who presented to the ER and 

who were assessed as having no needs for immediate medical or psychiatric treatment were then 

randomized to either hospital admission or discharge to home. Those admitted to the hospital 

received no additional counseling or specific treatment. “Hospital admission consisted of little 

more than a bed, without further referral to other helping agencies.” The median length of stay 

was 17 hours. The treatment group received the same instructions at discharge as the control 

group: to contact their general practitioners if the need for help arose. Thus, the treatment group 

differed from the control group only in the provision of hospital admission. For this pilot study 

the data were analyzed as if the junior doctor’s initial assessment had been used, while the actual 

decision was made by the psychiatrist. The outcome assessed was repeated suicide attempts. In 

the first week post-discharge, two patients in each group had repeated attempts; at 16 weeks 3 

patients in the treatment (admission) group had made repeated attempts, compared to 4 patients 

in the control group. The group sizes were not reported, so percentages can not be computed. No 

statistical measures were reported. 

In summary, a single program studied the effect of brief hospital admission without additional 

treatment. Insufficient outcomes data were reported to determine its efficacy or statistical 

significance.
27

Other RCTs

Unutzer et al.45 reported a multi-site trial in the US (including VA clinics in Texas) providing a 

collaborative care manager to primary care physicians to reduce suicidal ideation in depressed 

older patients. The depression care manager was a nurse or psychologist assigned to the primary 

care clinic; they assessed patients, educated patients about options for treating depression, and 

were in contact with the patients by phone or in-person every 2 weeks during the acute phase 

of treatment and monthly during the continuation phase continuing to 12 months. Patients in 

the control group and their primary care providers were informed that the patient met criteria 

for a depressive disorder; the patients could receive any of the available treatments, including 

antidepressants, counseling by the PCP, or referral for mental health care. Patients were 

randomly assigned to the treatment or the control groups. No completed suicides were reported 

in either group. The intended outcome measure reported for this trial was suicidal ideation, which 

did show statistically significant decreases at all follow up periods out to 24 months.

Mishara et al.46 described a program implemented in Montreal in 2000-2002 to reduce suicidal 

behaviors in suicidal or depressed men by providing assistance to family or friends of those 

men who called a suicidal support center. Family or friends of the suicidal men were randomly 

assigned to one of four treatment interventions: (1) an information session that provided 2.5 

hours of training in a group setting, (2) that information session plus phone follow up one 

week hence, (3) “rapid referral” for the suicidal man in which the family/friends had two inperson meetings with staff from the suicide center focusing on how to get the suicidal man into 

treatment with an appropriate agency, (4) telephone support counseling with flexible scheduling 

of follow up calls. The outcome assessed was suicide attempt. Results were not broken down 

by treatment group, and there was no control group providing treatment as usual, so the data 

were analyzed comparing post-intervention to pre-intervention. At study entry 22.9% of the 

participants reported a suicide attempt in the man in the previous 2 months; at 2 month follow up 

10.6% reported an attempt in the previous 2 months, and at 6 month follow up 2.7% reported an 

attempt in the previous 2 months. Each of these differences was a statistically significant change. 

Participants also rated these programs as helpful to the men and the participants.

In summary, two other randomized, controlled trials were identified. The first, a high quality 

RCT, reported a collaborative care program in primary care clinics, and found no suicides in 

either the treatment or control groups. The second provided an intervention to the family or 

friends of men at high risk for suicide; the study was methodologically very weak and did not 

report the effect of treatments in comparison to a control group.

Restriction of access to lethal means

A large number of studies using observational data for restriction of access to lethal means were 

identified. These are grouped by means, first with firearms restriction, and then acetaminophen, 

and finally other toxicological agents.
28

Restriction of access to firearms

Twenty studies were identified concerning restriction of access to firearms. These are 

summarized in Evidence Table 3. 

Restriction to access to firearms in the US

Loftin et al.47 reported the effect of restrictive licensing of handguns in Washington, D.C., that 

began in 1976, and which “prohibited the purchase, sale, transfer, and possession of handguns 

by civilians,” unless the firearm had been previously registered. They compared monthly suicide 

rates before and after the implementation of the law and found that the mean number of suicides 

per month declined from 2.6 to 2.0. This was statistically significant, both by a simple sampling 

model and also by an autoregressive integrated moving average (ARIMA) model commonly 

used in time-series modeling. To address the problem of secular changes, they studied non-gunrelated suicides in the same region, and gun-related suicides in neighboring regions not subject to 

the law, and found no statistically significant decline in either measure over the same period. This 

handgun law was found to be unconstitutional by the US Supreme Court in June, 2008.

Ludwig and Cook48 studied whether the introduction of the Brady Handgun Violence Prevention 

Act in the US, which instituted background checks and waiting periods, was associated with a 

reduction in suicide rates. Some states already met one or both of the requirements and served 

as controls; the authors also used regression modeling to control at the state level for alcohol 

consumption, and percentage of population in metropolitan areas, percentage below the poverty 

line, percentage African-American, and percentage in each of 7 age groups. They found that 

suicide rates had begun to fall before the introduction of the Brady Act; the Act was correlated 

with a reduction in suicides in victims 55 years or older, but only in states that changed both their 

waiting-period and background-check requirements.

Lott and Whitley49 examined the effect of safe-storage gun laws in the US (which varied by 

state), and suicides in adolescents, including those in the age range of 15-19 years. Using data 

from the years 1979 to 1996, during which time 15 states adopted safe-storage laws (the year of 

enactment ranged from 1989 to 1996), they used weighted tobit regression models predicting the 

per capita suicide rate from a variety of fixed effect and control variables. The results showed 

a 5% decrease in gun suicides attributable to the safe-storage law; this was not statistically 

significant. A second set of more sophisticated regression models found: “... a couple of 

coefficients that indicated that gun suicides declined after the passage of the safe-storage law. 

However, in these cases, the evidence clearly rejects the hypothesis that the total number of 

suicides, committed by all methods, would be reduced.”(p677). They did not provide the details 

supporting those results.

A similar study by Rosengart et al.50 examined various kinds of handgun restriction laws in the 

US, using data from 1979 to 1998, and found that no law was statistically significantly associated 

with a change in the firearm suicide rate (in any age group). Webster et al.51 examined related 

data from 1976 to 2001, for the age group of 18-20 years of the effects of minimum purchase age 

or child access prevention laws. They, found results that were either statistically insignificant or 
29

were of questionable causal believability for that age group.

Restriction of access to firearms in Canada

In Canada, a firearms control law was enforced starting in 1978 that required licensing, restricted 

certain sales, and increased criminal penalties for crimes involving firearms. The effects of this 

law have been examined in a number of studies, reported here chronologically.

Rich et al.52 examined the law’s effect in Toronto and Ontario. Mean rates in the five year periods 

before and after the law were compared; the data for the year 1978 were withheld because of 

the transition during the year. There was a small but not statistically significant decrease in the 

suicide rate for Toronto or for Ontario. They did find a statistically significant decrease in the 

fraction of suicides by shooting for men in Toronto, and a statistically significant increase in 

the fraction of men committing suicide by jumping. They considered this evidence of method 

substitution.

Carrington and Moyer53 repeated the analysis of the data for Ontario studied by Rich et al.52 using 

a slightly different data source, extended to include 1965-1977 and 1979-1989, and using agestandardized rates in a regression analysis. They found statistically significant increases in the 

firearm, non-firearm, and total suicide rates in the pre-legislation period, and decreases in those 

three rates (not significant for firearm suicide) in the post-legislation period. They considered 

their results as suggesting no method substitution. 

Lester and Leenaars54,55 looked at the law’s effect for all of Canada for the 8 years prior (1969 to 

1976) and eight years after (1978 to 1985). Examination of the raw statistics showed that the rate 

of suicide by firearm and fraction of suicide by firearm had a statistically significant decrease, 

but that both the overall suicide rate and the suicide rate by other means increased. A post-hoc 

linear regression analysis showed that before the law, the rates for suicide by firearm and by 

other methods, along with the fraction of suicides by firearm were all increasing, while after 

the law was enforced, these quantities were all decreasing (although the suicide rate by other 

methods was not statistically significant). They concluded that there was not evidence for method 

substitution.

Leenaars and Lester56 examined the same data separately for men and women. For men, the 

firearms suicide rate and the rate for other methods both increased in the post-legislation period, 

while the fraction of men using firearms for suicide decreased. They considered this is as 

evidence of switching in men. For women, the rates were stable or declined, and there was no 

evidence for switching.

Lester57 reanalyzed the Canadian data using two alternative measure of firearms availability: 

accidental death rate from firearms, and average of fraction of suicides and homicides committed 

by firearm. These data were available for 1970 to 1995. One or both of these measures was 

statistically significantly correlated with the firearm suicide rate (positively) and both the total 

suicide rate and the suicide rate by other methods (negatively). Lester also found a negative time 

trend for the firearm suicide rate, and a positive time trend for the suicide rate by other methods. 
30

Lester concluded that these data were consistent with method substitution.

Leenaars and Lester58 reexamined the Canadian data to determine the effect of the legislation on 

suicide rates by age group. The post-legislation mean handgun suicide rates declined for ages 35-

44, 45-54, and 55-64 (all statistically significantly), and increased for ages 15-24, 25-34, 65-74, 

and 75+ (the increases for 25-34 and 65-74 were not statistically significant). They concluded 

that there was little evidence for the effectiveness of the act in reducing suicide for those 65 and 

up.

Leenaars et al.59, looked at the same data using regression modeling. The firearm suicide rate 

showed an increasing trend before the legislation, no step-effect at the time of the legislation, and 

a negative slope for the interaction term, indicating a declining trend after the legislation. The 

same pattern was seen in the data for men only, but for women the pre-legislation trend was not 

significant and the post-legislation decline was statistically significant but small in magnitude. 

The results also suggested a displacement effect for men, but not for women. The authors also 

conducted a multivariate regression including a variety of social indicators, such as income, and 

birth, marriage, and divorce rates as predictor variables. This showed a statistically significant 

decrease in firearm suicide rates for both men and women, and evidence for switching in men.

Bridges60 used a similar approach to examine the effect of a different Canadian law passed in 

1991 that mandated additional pre-purchase screening and a 28-day waiting period over 7 years 

periods before and after the introduction of the law. The mean rate for firearm suicide and the 

fraction of suicide by firearm decreased, while the total suicide rate increased. Trends were 

checked by using separate linear regressions in the pre- and post-legislation periods. The total 

suicide rate, the firearms suicide rate, the rate for other methods, and the fraction of suicides 

by firearm all had negative slopes in the pre-legislation period; in the post-legislation period 

there were negative (but small) slopes for the firearms suicide rate and the fraction of suicide by 

firearms. There was no evidence for switching.

Cheung and Dewa61 examined the effect of the same Canadian 1991 law on the suicide rate 

in adolescents ages 15-19. Using a time-series model over the years 1979-1999, they found 

a decrease in the firearms suicide rate after 1991, but a corresponding increase in the rate of 

hanging, consistent with method switching.

Restriction to access to firearms in Australia/New Zealand

Snowdon and Harris62 looked at the firearm suicide rate in Australia’s five largest states, one 

of which (South Australia) enacted a stringent firearm examination and licensing law in 1980. 

The suicide rates were examined over the years 1968 to 1989. The rate in South Australia was 

statistically significantly lower when compared to the four other states, and when compared 

directly with the state of Victoria, the most similar state on demographic measures. The decrease 

in South Australia was accompanied by an increase in suicide by other means. They were unable 

to reach firm conclusions about method substitution.

Chapman et al.63 studied whether Australia’s firearms restrictions, which were enacted in 1996 
31

and included prohibitions on private ownership of semi-automatic and pump-action rifles and 

shotguns, and also a buy-back program of existing firearms, were associated with a reduction in 

suicide rates. The data were analyzed using a negative binomial model. The authors reported that 

the firearm suicide rate, which was already decreasing at 3% per year, further dropped to 7.4% 

per year after the law change. The total suicide rate changed from a 2.3% increase per year to a 

4.1% decrease, although at the time of the law change, the total rate did transiently increase in 

absolute numbers. 

Cantor and Slater64 examined the effect of firearm control legislation in the state of Queensland 

requiring a 28 day waiting period and a safety test which came into effect in 1992 on the suicide 

rate in metropolitan, provincial, and rural areas in that state. The mean annual suicide rate per 

100,000 in the two years before the change was compared to the rate in the two years following 

the change. There were statistically significant decreases in the firearms suicide rate in the 

metropolitan (3.6 to 2.3) and provincial (5.2 to 3.1) but not in the rural areas (7.2 to 8.2, nonsignificant). A subgroup analysis showed that the significant decreases were in men age 15-29 

in the metropolitan and provincial areas. There were statistically significant increases by men in 

metropolitan and provincial areas in the use drug overdose and hanging, although the total rate 

for men decreased slightly.

Ozanne-Smith et al.65studied the effect of firearm regulation in Australia, introduced first 

in the state of Victoria, and then several years later in the rest of Australia. The legislation 

banned certain classes of firearms, required registration and a safety class, and included a 1 

year longarms buyback scheme. They used a Poisson regression model with data over three 

periods: 1979-86 (no legislation), 1988-1995 (legislation introduced in Victoria), and 1997-2000 

(similar legislation introduced in rest of Australia). The suicide rates in Victoria declined in each 

successive period at a statistically significant rate (a 72% decline in the average annual frequency 

from the first to the third period). They did not report on data directly relevant to the problems of 

displacement or method substitution.

Beautrais et al.66 reported on reduction of suicide rates in New Zealand associated with restrictive 

firearms legislation, enacted in 1992, and which mandated police assessment, testing, and 

licensing of gun owners, along with strict requirements for gun security and storage. Their 

analysis used a variety of regression models, including Poisson regression, a time-series 

forecasting model, a polynomial model, and an auto-regressive model, over three intervals: 

before the implementation, the four-year period of implementation (1993-96), and after the 

implementation period. They reported a decline in the suicide rate for youth (15-24y), adult 

(25+y), and combined populations over time; this trend was most marked for youth suicide. 

A similar pattern was seen for firearm suicide as a percentage of total suicides. Use of various 

models showed no evidence for a decline in the overall rate of suicide.

In summary, a large number of studies concerning restricting access to firearms were identified. 

A number of the studies reported variations on analyses of the same or very similar data sets. 

All compared the suicide rates before and after the implementation of laws restricting access 

to firearms. Methodological issues common to the analysis of observational data were present, 

especially addressing statistical fluctuations by using longer windows for the pre- or post-
32

intervention periods, while trying to minimize the effect of other, unmeasured, socioeconomic 

trends, such as changes in the divorce or unemployment rate. The results as reported are mixed, 

but suggest some protective effect at least in some groups as determined by age and gender. 

The question of possible shifts to other methods leading to no net reduction in suicide (method 

substitution) remains unresolved.

Restriction of access to acetaminophen (UK: paracetamol, US Brand: Tylenol, others)

The UK enacted legislation in September 1998 that limited the package size of paracetamol 

and salicylates (including aspirin). Paracetamol is commonly used in suicide by overdose and if 

untreated can cause fatal liver failure. The effect of this legislation has been reported in a number 

of studies, presented here chronologically.

Prince et al.67reported on the number of patients referred to a tertiary care liver unit at a single 

hospital, and the number of national liver transplantation requests from September 1995 to 

August 1999. Monthly rates for both declined after the legislation, in spite of a preexisting 

increasing trend in national transplant referrals. 

Turvill et al.68 reported on the number of paracetamol overdoses at one London hospital from 

September 1995 to August 1999. The number of overdoses declined by 21% (with a 64% decline 

in severe overdoses, as determined by existing guidelines) after the legislation. There was no 

change in the rate of benzodiazepine overdoses, which served as a control measure.

Robinson et al.69 measured the several parameters before the legislation (January through June 

1998) and after (same months, 1999) in patients at a hospital in Belfast. They found statistically 

significant decreases in the estimated quantity of paracetamol ingested, the serum paracetamol 

concentration, the percentage of patients admitted to the hospital, the percentage of patients 

given antidote, a measure of liver function (INR) and concentrations of liver enzymes.

Steen et al.70 examined the effect of the legislation on paracetamol-related deaths in Scotland. 

They compared all paracetamol-related deaths in the years 1996-1997 and the years 1999-2000. 

The rate for the two years preceding the year of implementation was 1.93 per 100,000; the rate 

for the latter two years was 1.78 per 100,000. This change was not significant by the chi-square 

test. Informally, they observed a declining trend in the paracetamol-only deaths in males before 

the legislation, which reversed in the year 2000. They also noted that Scotland has a markedly 

higher suicide rate than England or Wales. 

Hughes et al.71 counted the number of admissions to a Birmingham, UK hospital or a related 

hospital’s liver unit as the result of paracetamol poisonings for three years before and three years 

after 1998. Hospital admissions showed a 31% reduction, and liver unit admissions showed a 

50% reduction. No statistical analysis was conducted.

Hawton et al.72 and Hawton73 compared the suicide deaths in the two years before the change 

with the deaths in the year after the change. There were statistically significant reductions in 
33

deaths for both classes of compounds considered individually, but not when taken with other 

drugs or taken together. They also found that the number of admissions to hospital liver units 

and the number of liver transplantations declined over the same intervals. The number of nonfatal self-poisonings with paracematol or salicylates declined in absolute numbers, comparing 

the previous year to the subsequent year, but there was no decline the proportion of total cases 

of self-poisoning. They concluded that “legislation restricting pack sizes of paracetamol and 

salicylates in the United Kingdom has had substantial beneficial effects on mortality and 

morbidity associated with self-poisoning using these drugs.”

Hawton et al.74 repeated the above analysis, adding another post-legislation year, and also 

included trend modeling with data from 1993 to 2002 to test for step change at the time of the 

legislation. They found a 29% decrease in paracetamol-related deaths, and 46% decrease in 

salicyclate-related deaths. They also evidence for a downward step change for both paracetamol 

and salicyclate overdoses at the time of the legislation. Liver unit admissions, liver transplants, 

and nonfatal paracetamol and aspirin overdoses decreased after the legislation. 

Morgan et al.75 analyzed UK national data for the package restriction using chi-square (and later 

analyzed the same data using segmented linear regression: Morgan et al.76). To control for secular 

trends, they compared the paracetamol deaths to those from paracetamol in combination with 

other compounds, aspirin (which was also limited by the same legislation), antidepressants, and 

non-drug poisoning suicides. There were declines (negative slopes) in age-standardized mortality 

rates for all the groups studied. There was a downward step change in those rates for paracetamol 

poisoning, with a similar step change for aspirin and antidepressants, but not for paracetamol 

compounds or non-drug poisoning suicides. Thus, while the paracetamol deaths declined, other 

suicide deaths also declined over the same period. They conclude that there is “little evidence” to 

associate the reduction in paracetamol-related suicides with the package size reductions.

Similar restrictions in Ireland were introduced starting in October 1997. An abstract by Donohoe 

and Tracey77 reported no statistically significant difference in the number of overdose cases 

reported to the National Poisons Information Centre in Dublin in 1998, compared to 1997. There 

was a slight but not statistically significant decline in severe overdoses.

For Australia, Balit et al.78 reported on the effect of a recall of paracetamol-containing products 

during two periods in 2000 in response to threatened insertion of poisons into those products. 

The outcome measures were the number of calls to a poison information center and the number 

of admissions to a toxicology inpatient service, both in New South Wales. These measures during 

the recall periods were compared with corresponding measures in the same months of the three 

preceding years (1997-1999). At one site, there was no statistically significant change in the 

percentage of calls for paracetamol or aspirin, but an increase for ibuprofen; at the other site, 

there was no statistically significant change in the presentations for paracetamol or ibuprofen, but 

an increase for aspirin. They concluded that there was no reduction in deliberate self-poisonings 

during a period of restricted availability.

In summary, a number of studies of the effect of UK restrictions on paracetamol showed declines 

in suicides coincident with those restrictions. However, there is some evidence from time-series 
34

modeling that this was part of a longer downward trend in suicide. Many of the studies had 

very short post-intervention periods. A small of number of studies in other countries reported 

equivocal results. Unlike the area of restriction of access to firearms, there was little analysis of 

method substitution.

Restriction of access to respiratory toxins

Kreitman79 studied deaths due to asphyxiation by “domestic gas” in the UK (England, Wales, 

Scotland) in relationship to changes in the production of such gas from coal to natural gas that 

significantly lowered the carbon monoxide content over approximately a decade starting in the 

late 1950s. Kreitman reported that the reduction in carbon monoxide content was paralleled by 

a drop in carbon monoxide poisoning deaths during that same interval; this was found in both 

sexes and all age groups. The decline was significant enough to overcome an increase in the 

other rates of suicide for both young men and women to produce a net overall decline.

Kendell80 reported data on the effect in Scotland of the UK regulation requiring all cars sold after 

December 31, 1992 to have catalytic converters, thereby decreasing the carbon monoxide content 

of the exhaust gas. For men, the fraction of all suicides attributed to poisoning by gases other 

than domestic gas showed a statistically significant decline (chi-square for trend), with a smaller 

but also statistically significant decline for women. A data over a somewhat shorter interval in 

England and Wales showed the same pattern.

Amos et al.81 studied deaths due to carbon monoxide poisoning by car exhaust in England and 

Wales for the years before (1987-1992) and after (1993-1998) European legislation requiring that 

all new car have catalytic converters. For all age groups and both sexes there was a decline in 

deaths from car exhaust, and in the percentage of all suicides that were due to car exhaust. These 

comparisons were made using the raw statistics, not age/population adjusted numbers. They 

also performed a hierarchical multiple linear regression that included an interaction term that 

was the product of the two study periods; however, they reported only the statistical tests on the 

regression analysis, not the coefficients. They noted that the decline in car exhaust asphyxiations 

had started, at least in some groups, prior to the implementation of the law.

Routley82 conducted a similar study in Australia, where 1986 regulations added catalytic 

converters to new cars. Using data from 1971 to 1995, they found that motor vehicle exhaust 

gas suicide rates increased generally increased over time, even after the regulation. Numbers of 

patients hospitalized for motor vehicle exhaust gas suicide attempts also increased during the 

interval. A sample of 100 cases of exhaust gas suicide in the state of Victoria were reviewed. The 

fraction of vehicles used in these suicides manufactured after 1986 was not significantly different 

from the fraction for the Victorian motor fleet at large. They concluded that catalytic converters 

were not associated with a decline in motor vehicle exhaust suicide number, rate, or proportion.

In summary, four studies were found concerning restricting access to respiratory agents. One 

study found that changing the source of domestic gas in the UK resulted in a decrease in carbon 

monoxide poisonings. The effect of catalytic converters on car exhaust asphyxiation reported in 

three studies was mixed.
35

Access to/effect of pharmacologic agents

Oliver and Hetzel83 reported on the relationship between changes in the availability of sedative 

drugs due to subsidization of health care in Australia in 1960, which increased the availability 

and a subsequent reduction in 1967 of the amounts provided in each prescription, and the effect 

on the national suicide rate over the same time period. They found an increase in the incidence of 

barbiturate deaths in adults during the time of increased availability, and a subsequent decrease 

with the limitation on sedative amounts.

Whitlock84 conducted a similar study in Brisbane, Australia, for the years 1962 to 1973, and 

found a similar result: that barbiturate suicide deaths tracked their increase and then decrease 

in availability. This effect was more prominent in women, for whom barbiturate overdose 

was more common. There was already an increasing trend in suicide rates before the increase 

associated with the availability of barbiturates. Whitlock also addressed the changing use of 

other medications, such as benzodiazepines and antidepressants, which might have substituted 

for barbiturates, either therapeutically or as methods of self-poisoning, but the fact that the 

changes in use extended over multi-year periods, and the lack of a single intervention greatly 

complicates the analysis of this observational data, and the detection of method substitution and 

secular trends. Whitlock did note that there had been no deaths from carbon monoxide poisoning 

in those aged 65 and older after 1967, when domestic gas was switched to a nontoxic source. 

In summary, two studies in Australia on the effect of access to sedative drugs lethal in overdose 

showed a decline in the suicide rate that tracked restrictions on their availability.

Bridge barriers

One study on the effect of bridge barriers in reducing suicide by jumping was identified.

Beautrais85 reported on the effect of removing existing screens from a bridge in an “Australasian 

metropolitan area.” The location was described in a disguised fashion so as to avoid attracting 

further attention to it. Existing screens were removed by the action of the city council in 1995 

because they were felt to actually impede access to rescuing suicide attempters and for aesthetic 

reasons. Suicide rates by jumping at that bridge and other bridges were compared in three-year 

periods before and after the barrier removal. The rate (per 100,000) at the bridge before the 

barriers were removed was 0.29; this increased to 1.29 after the removal. The number of suicides 

at the other bridges declined after the barrier removal, and the citywide total before and after 

remained constant. Beautrais presented additional data on the subject’s mental health diagnosis 

(mostly, schizophrenia) suggesting that the act of barrier removal increased the suicide rate for 

mental patients because of its location near the regions largest inpatient psychiatric facility, and 

that the removal did not merely shift suicides from other bridges.

In summary, a single observational study reported an increase in suicide by jumping after 

protective screens were removed from a bridge; there was some evidence that the removal led to 

an actual increase in suicide, not merely displacement from other bridges.
36

Restriction on Media Reporting of Suicides

One controlled study reported on media restriction of reporting of suicides.

Motto86 examined the suicide rate in Detroit during a 268-day period in 1967-8 when a 

newspaper strike lead to the complete cessation of publication. The suicide rate of the blackout 

period was compared to the average rate during the same days in the previous four years. The 

rate for men was the same (16.7 per 100,000), while the rate for women dropped from 7.6 to 3.0; 

the decline was statistically significant. An overall declining trend starting before the blackout 

period was noted. 

In summary, a single observational study on media restriction during an extended newspaper 

strike showed a decline in suicides for women, and no change for men. There may have been an 

preexisting declining trend in suicide starting before the strike.

Key Question #3: What evidence is still needed to establish various strategies as the most promising (framed as 

research questions to guide and focus continued research 

to expand knowledge regarding the effectiveness of suicide 

prevention approaches)?

Multifaceted interventions are supported by consistent evidence, although of very mixed quality. 

Even if such programs are later determined to be robustly successful, the question of which 

components in those programs are causally related to the reduction in suicides has not been 

addressed. This sets as a research issue determining which components work best in which 

combinations for which populations. The issue of whether some sets of components may have 

facilitative or synergistic effects has not been addressed.

Psychosocial intervention for suicide attempters have considerable face validity as they address a 

group with manifest evidence of suicide risk, but there is no consistent evidence in their support 

in spite of a moderate number of randomized controlled trials that been conducted. This is an 

area of obvious and considerable interest to the VA, which is now using similar approaches in its 

clinical programs to identify and track those at high risk with suicide risk flags, screening tools, 

and suicide prevention coordinators. An additional factor that seems relevant but rarely directly 

studied is the effect of forming a consistent relationship with a single provider, a therapeutic 

alliance, and its role in providing a protective degree of social connection, and reducing the 

harmful consequences of social isolation.

Further randomized controlled trials and high-quality observational studies are definitely needed. 

Without waiting for such to be completed, and independent of which program components the 

VA decides to pursue, there are two supporting initiatives that could be implemented in parallel. 

The first concerns standardizing vocabulary, and the second concerns electronic medical records.
37

First, all suicide prevention programs are dependent on the accuracy with which assessments of 

suicidality are conducted. The term “suicide attempt” covers a very broad array of self-injurious 

behaviors, from intentionally planned, high lethality events that were interrupted by mere 

happenstance, through low lethality acts marked by a small risk of physical harm, impulsivity, 

and a high likelihood of discovery by others. Others have noted the importance of establishing 

and using a consistent nomenclature in this area.

A very important reason for accurately describing the severity of suicide attempts is that 

an attempt is widely recognized as a significant risk factor for completions. Although most 

completed suicides are first attempts2

 and attempters vary in important ways from completers,3 it 

is known that survivors of highly lethal attempts have similar clinical and psychosocial profiles 

to antemorten profiles of suicide completers. This suggests that subcategorization of attempt by 

lethality (or perhaps other factors) may be clinically useful.

Second, because the VA uses a single, integrated computerized medical record system for all of 

its clinical activities, any improvements in vocabulary along with new screening and tracking 

tools would allow for data gathering as part of routine practice – especially for establishing 

patterns and risk factors for suicide attempts – in advance of formally conducted observational 

studies or controlled trials. 
38

Summary and Discussion

In this chapter, we describe the limitations of our review and then present our conclusions. We 

also discuss the implications of our findings for future research. 

Limitations 

Publication Bias

Our literature search procedures were extensive. It was not possible to conduct formal tests for 

publication bias, but even with such tests it is not possible to exclude the possibility that such 

bias exists. Therefore, readers are cautioned about this possibility.

Study Quality 

An important limitation common to systematic reviews is the quality of the original studies. 

Recent attempts to define elements of study design and execution that are related to bias have 

shown that in many cases, such efforts are not reproducible and do not distinguish study results based on bias. Therefore, the current approach is to avoid rejecting studies or using quality criteria to adjust the results of the review. We did use the Delphi list criteria as a descriptive 

measure of quality.11 As there is a lack of empirical evidence regarding study characteristics and 

their relationship to bias, we did not attempt to use other criteria. Other aspects of the design and 

execution of a trial may be related to bias, but we do not yet have good measures of these elements. Because of the small number of studies found, it was not possible to do sensitivity analyses based on study quality. 

Heterogeneity 

Clearly, the populations being assessed were different, and there were also important differences 

in how some key variables were measured, characteristics of the interventions, and outcomes 

measured, among others. This heterogeneity further limits our ability to draw strong conclusions.

Applicability of Findings 

Green & Glasgow87 provide a framework for evaluating the relevance, generalization, and applicability of research. Their framework includes assessing the participation rate, the intended 

target population, the representativeness of the setting, the representativeness of the individuals, 

and evaluating information about implementation and assessment of outcomes. As these data are 

rarely reported in the studies we reviewed, conclusions about applicability are necessarily weak.

Comparison with Systematic Reviews and Meta-analyses

We now discuss how our results relate to those published in other, similar systematic reviews and 

meta-analyses.

Gaynes et al.7

 presented a systematic review for the US Preventive Services Task Force on 

screening for suicide risk in adults with a focus on primary care settings. They found “extremely 

limited” evidence that could be used for assessment and management of the risk of suicide by 

primary care clinicians. “No studies address the overarching question of whether screening for 
39

suicide risk in primary care patients improves outcome.... Regarding whether interventions 

for those at risk reduce suicide attempts or completions, the poor generalizability of the studies 

makes the overall strength of evidence fair, at best, while the results are mixed. Although 

some trends suggest incremental benefit from several interventions, no consistent statistically 

significant effects have emerged for interventions for which more than 1 study has been done.”

Mann et al.1

 whose conceptual model and results guided the construction of our review, 

concluded that “the most promising interventions are physician education, means restriction, 

and gatekeeper education.” However their conclusion about physician education was based on 

studies in countries (Hungary, Japan, and the island of Gotland, Sweden) whose suicide rates and 

patterns are not similar to those in the US population. The gatekeeper education result followed 

from a single study, the multifaceted USAF suicide prevention program, which actually provided 

significantly more services than just gatekeeping.

Morgan and Majeed88 reviewed the UK studies on paracetamol restriction, and found some 

evidence for a decrease in admission to liver units and transplant requests after the introduction 

of the restrictions. However, they noted as complicating factors small sample sizes, the lack of a 

precise definition of paracetamol poisoning, and the absence of any control groups in the studies 

examined. They also observed that in spite of the restrictions, paracetamol was still commonly 

used as a means of suicide.

Hawton et al.89 conducted a review for the Cochrane Collaboration on psychosocial and 

pharmacological treatments for deliberate self-harm. They found non-significant trends for 

problem-solving therapy, provision of an emergency contact card, intensive aftercare plus 

outreach, and antidepressant treatment. They concluded that “considerable uncertainty” 

remained, and that the clinical trials reviewed to date had been too small.

Crawford et al.90 reported a systematic review of RCTs for psychosocial interventions following 

episodes of self-harm, and for 18 studies found no difference in the suicide rate between 

treatment and control groups. Three of the studies involved children or adolescents. Crawford et 

al. also included psychotherapeutic interventions – none of which were included in our review. 

Sample size and lack of statistical power were identified as complicating factors. They argued for 

pursuing public health approaches, such as means restriction and media guidelines for reporting.

Other non-systematic reviews

One non-systematic review relevant to our report was identified. Lester91 reviewed the evidence 

supporting the use of suicide prevention centers. Fourteen independent studies were identified, of 

which seven showed evidence for protective effects, but these were not consistent across gender, 

age groups, and suicide methods. When protective effects were found, they were often small 

in magnitude. Lester combined the studies using a meta-analysis, which did achieve statistical 

significance, with a correlation coefficient of –0.16 (which is equivalent to an effect size of 

–0.32).
40

Reviews of mental health interventions

Our review did not focus on purely mental health interventions. These have been the subject 

of other reviews. Perhaps somewhat surprisingly given the role of depressive disorders as 

significant risk factors for suicide, the evidence in support of the use of antidepressants is rather 

weak. Isaacson and Rich92 in nonsystematic review on the protective effects of antidepressants 

for suicide concluded, in part, “Pooled data from controlled clinical trials of antidepressants have 

not demonstrated a suicide preventive effect, but patient selection and the brief time of most 

trials limits the power of the data. Some reports from either long-term or very large databases 

have provided evidence that antidepressants prevent suicide.”(p153)

Some of the best evidence for psychopharmacologic interventions that reduce suicide risk is 

for lithium in the treatment of bipolar disorder. Baldessarini et al.93 reported a meta-analysis 

of 31 published studies that showed a robust protective effect of lithium for both completed 

and attempted suicides for both bipolar disorder and other mood disorders. There is also 

some evidence supporting the use of the antipsychotic clozapine to reduce suicide attempts in 

schizophrenia. Further details appear in a non-systematic review by Hennen and Baldessarini94

and a systematic review by Aguilar and Siris.95

Conclusions

With the above limitations in mind, we reached the conclusions displayed below.

KEY QUESTION #1: What are the new or improved suicide prevention strategies (e.g., 

hotlines, outreach programs, peer counseling, treatment coordination programs, and new 

counseling approaches) that show promise for Veterans?

KEY QUESTION #2: What solid evidence base supports the most promising strategies?

Multicomponent interventions in military personnel probably reduce the risk of suicide. The 

largest and best described such study is by Knox, and this article provides the most convincing 

evidence of effectiveness. The report of success of a program in Yugoslavia modeled after the 

Knox program increases our confidence that the effect is real. A similar program was developed 

for the US Navy and Marine Corps. However, as with any multicomponent intervention shown 

to be successful, there are still numerous questions about the relative merit of inclusion of 

each individual component (could the same effect be achieved with fewer components?) or the 

possible increase in effectiveness of adding other components, and optimizing the effectiveness 

of each additional component. Additionally, there are no data about its effect in non-military 

populations, although veterans would seem to be sufficiently close to a military population that 

some transferability of results could be assumed. (GRADE quality of evidence = Low, meaning 

further research is very likely to have an important impact on our confidence in the estimate of 

effect and is likely to change the estimate)
41

There are insufficient studies of suicide prevention programs specifically in veterans to draw 

conclusions (GRADE quality of evidence = Very Low, meaning any estimate of effect is 

uncertain)

Psychosocial interventions following a suicide attempt are, at the very best, only minimally 

effective (GRADE quality of evidence = Moderate, meaning further research is likely to have an 

important impact on our confidence in the estimate of the effect and may change the estimate).

There are insufficient data to reach conclusions about Community-based Suicide Prevention 

Centers (GRADE quality of evidence = Very Low , meaning any estimate of effect is uncertain)

We found no studies that assessed the specific effectiveness of any of hotlines, outreach programs 

as primary prevention interventions, peer counseling, treatment coordination programs, and new 

counseling programs.

Restriction of access to lethal means probably has an effect on cause-specific suicides, although 

its effect on total suicides is less clear (GRADE quality of evidence = Low, meaning further 

research is very likely to have an important impact on our confidence in the estimate of effect 

and is likely to change the estimate)

KEY QUESTION #3: What evidence is still needed to establish various strategies as the 

most promising (framed as research questions to guide and focus continued research to 

expand knowledge regarding the effectiveness of suicide prevention approaches)?

Multifaceted interventions are supported by consistent evidence, although of very mixed quality. 

Even if such programs are later determined to be robustly successful, the question of which 

components in those programs are causally related to the reduction in suicides has not been 

addressed. This sets as a research issue determining which components work best in which 

combinations for which populations. The issue of whether some sets of components may have 

facilitative or synergistic effects has not been addressed.

Psychosocial intervention for suicide attempters have considerable face validity as they address a 

group with manifest evidence of suicide risk, but there is no consistent evidence in their support 

in spite of a moderate number of randomized controlled trials that been conducted. This is an 

area of obvious and considerable interest to the VA, which is now using similar approaches in its 

clinical programs to identify and track those at high risk with suicide risk flags, screening tools, 

and suicide prevention coordinators. An additional factor that seems relevant but rarely directly 

studied is the effect of forming a consistent relationship with a single provider, a therapeutic 

alliance, and its role in providing a protective degree of social connection, and reducing the 

harmful consequences of social isolation.

Further randomized controlled trials and high-quality observational studies are definitely needed. 

Without waiting for such to be completed, and independent of which program components the 
42

VA decides to pursue, there are two supporting initiatives that could be implemented in parallel. 

The first concerns standardizing vocabulary, and the second concerns electronic medical records.

First, all suicide prevention programs are dependent on the accuracy with which assessments of 

suicidality are conducted. The term “suicide attempt” covers a very broad array of self-injurious 

behaviors, from intentionally planned, high lethality events that were interrupted by mere 

happenstance, through low lethality acts marked by a small risk of physical harm, impulsivity, 

and a high likelihood of discovery by others. Others have noted the importance of establishing 

and using a consistent nomenclature in this area.96 It is critical for further advances in suicide 

reduction that such attempts are carried through.

A very important reason for accurately describing the severity of suicide attempts is that 

an attempt is widely recognized as a significant risk factor for completions. Although most 

completed suicides are first attempts2

 and attempters vary in important ways from completers,3 it 

is known that survivors of highly lethal attempts have similar clinical and psychosocial profiles 

to antemorten profiles of suicide completers. This suggests that subcategorization of attempt by 

lethality (or perhaps other factors) may be clinically useful.

Completed suicides are thought to be more easily determined, as they are judged such on the 

basis of a coroner or medical examiner ruling. In most cases the determination is straightforward, 

but others, such as single-occupant car crashes, raise the issue of disguised suicides, where intent 

may have been willfully hidden for reasons of shame or insurance coverage. Crawford et al.90

noted difficulties in using reported suicides because of problems of ascertainment. Addressing 

these forensic issues is mostly outside the purview of the VA.

Second, because the VA uses a single, integrated computerized medical record system for all of 

its clinical activities, any improvements in vocabulary along with new screening and tracking 

tools would allow for data gathering as part of routine practice – especially for establishing 

patterns and risk factors for suicide attempts – in advance of formally conducted observational 

studies or controlled trials. 
43

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