Evidence-based Synthesis Program Department of Veterans Affairs

Health Services Research & Development Service

August 2011

Prepared for:

Department of Veterans Affairs

Veterans Health Administration

Health Services Research & Development Service

Washington, DC 20420

Prepared by:

Evidence-based Synthesis Program (ESP) Center 

Durham Veterans Affairs Healthcare System

Durham, N.C.

John W. Williams Jr., M.D., M.H.Sc, Director

Performance Characteristics

of Self-report Instruments

for Diagnosing Generalized Anxiety 

and Panic Disorders in Primary Care:

A Systematic Review 

Investigators:

Principal Investigator:

Sophiya Benjamin, M.D.

Co-Investigators:

Nathaniel R. Herr, Ph.D.

Jennifer McDuffie, Ph.D.

John W. Williams Jr., M.D., M.H.Sc

Research Associate:

Avishek Nagi, M.S.

Medical Editor:

Liz Wing, M.A.
i

Performance Characteristics of Self-report Instruments for Diagnosing 

Generalized Anxiety and Panic Disorders in Primary Care Evidence-based Synthesis Program

This report is based on research conducted by the Evidence-based Synthesis Program 

(ESP) Center located at the Durham VA Medical Center, Durham, NC, funded by the 

Department of Veterans Affairs, Veterans Health Administration, Office of Research and 

Development, Health Services Research and Development. The findings and conclusions in this document are those of the author(s) who are responsible for its contents; 

the findings and conclusions do not necessarily represent the views of the Department 

of Veterans Affairs or the United States government. Therefore, no statement in this 

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

No investigators have any affiliations or financial involvement (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.

PREFACE

Health Services Research & Development Service’s (HSR&D’s) Evidence-based Synthesis 

Program (ESP) was established to provide timely and accurate syntheses of targeted healthcare 

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

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

throughout VA.

HSR&D provides funding for four ESP Centers and each Center has an active VA affiliation. The 

ESP Centers generate evidence syntheses on important clinical practice topics, and these reports 

help:

• develop clinical policies informed by evidence,

• guide the implementation of effective services to improve patient outcomes and to 

support VA clinical practice guidelines and performance measures, and 

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

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

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

the Center established a Steering Committee comprised of HSR&D field-based investigators, 

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

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

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

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

VA healthcare system.

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

Coordinating Center Program Manager, at nicole.floyd@va.gov.

Recommended citation: Benjamin S, Herr NR, McDuffie J, Nagi A, Williams JW Jr. Performance Characteristics of Self-report Instruments for Diagnosing Generalized Anxiety and Panic 

Disorders in Primary Care: A Systematic Review. VA-ESP Project #09-010; 2011
1

Performance Characteristics of Self-report Instruments for Diagnosing 

Generalized Anxiety and Panic Disorders in Primary Care Evidence-based Synthesis Program

EXECUTIVE SUMMARY 

BACKGROUND

Generalized anxiety disorder (GAD) and panic disorder (PD) are two common mental illnesses that 

present in primary care clinics, often with physical symptoms that can inhibit appropriate diagnosis 

and treatment. Recognition of these disorders by primary care physicians is much lower than the 

expected rates—in part due to somatic presentations but also due to the lack of routine screening 

that is in place for some other mental illnesses. Patients with anxiety disorders are often high 

utilizers of health care resources, and when their anxiety disorders are not diagnosed and treated, 

they can frequently undergo more expensive testing to rule out medical causes.

Identification of accurate and feasible screening instruments for GAD and PD that have been 

validated in primary care settings have the potential to improve detection and facilitate treatment 

of these disorders within the primary care clinic, or to generate appropriate referral. Our report is 

a systematic review of the literture to evaluate the performance of self-report instruments used to 

diagnose GAD and PD in primary care settings.

Three key questions (KQs) guided this systematic review:

KQ 1. In general medical patients with somatic symptoms, what are the performance 

characteristics (e.g., sensitivity, specificity) of self-report questionnaires for diagnosing 

generalized anxiety disorder or panic disorder?

KQ 2. For questionnaires evaluated in KQ 1, which measures are most feasible to use in primary 

care settings? Specifically, what is the reading comprehension level, time required to complete, 

response format, and compatibility with telephone administration?

KQ 3. For questionnaires evaluated in KQ 1, do the performance characteristics vary by gender, 

race, age group, or setting?

METHODS

We searched PubMed® from 1980 to 2010 using standard search terms. We searched for primary 

studies and systematic reviews in MEDLINE® (via PubMed), PsycINFO®, and the Cochrane 

Library. We limited the search to peer-reviewed articles involving adult human subjects and 

published in the English language. Additional citations were identified from reference lists of 

articles included at the full-text review level. Titles, abstracts, and articles were reviewed in 

duplicate by investigators trained in the critical analysis of literature. Data were extracted by 

quantitative analysts. Pooled analyses were performed when appropriate. All other data were 

narratively summarized.

Study characteristics, patient characteristics, and outcomes were extracted by trained research 

staff under the supervision of the Program Director. We assessed study quality according to 

the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria modified for this 

specific research question.
2

Performance Characteristics of Self-report Instruments for Diagnosing 

Generalized Anxiety and Panic Disorders in Primary Care Evidence-based Synthesis Program

DATA SYNTHESIS

We constructed evidence tables showing study, patient, and intervention characteristics; 

methodological quality; and outcomes, organized by key question. We analyzed studies to 

compare their characteristics, methods, and findings. We compiled a summary of findings for 

each question based on qualitative and semiquantitative synthesis of the findings and provided a 

final assessment of the current evidence based on the Grades of Recommendation, Assessment, 

Development, and Evaluation (GRADE) Working Group criteria.

PEER REVIEW

A draft version of the report was reviewed by technical experts as well as clinical leadership, and 

their comments are provided in the appendix.

RESULTS

We screened 2890 titles, rejected 2824, and performed a more detailed review of 66 articles. 

From these, we identified no recent systematic reviews and 12 observational reports on 9 unique 

studies that addressed one of the key questions.

KQ 1. In general medical patients with somatic symptoms, what are the performance characteristics (e.g., sensitivity, specificity) of self-report questionnaires 

for diagnosing generalized anxiety disorder or panic disorder?

We identified eight screening instruments for the detection of GAD and PD in primary care 

patients. Of these, the Generalized Anxiety Disorder-7 (GAD-7; sensitivity 89%, specificity 

82%) and the panic module of the Patient Health Questionnaire (PHQ; sensitivity 80%, 

specificity 99%) had the best performance characteristics for the diagnosis of GAD and PD, 

respectively. The Symptom Driven Diagnostic System–Primary Care (SDDS-PC) also had good 

performance characteristics and is a multicomponent instrument that screens for GAD and PD as 

well as other mental illnesses.

All of the above instruments have been evaluated in reasonably sized primary care populations; 

however, none of these studies have been rigorously replicated. Even the SDDS-PC instrument 

that was evaluated in two studies consisted of two different versions. Therefore, evidence for 

these instruments is based on a single, well-conducted study for each instrument. Heterogeneity 

among the studies was high, prohibiting statistical pooling of data except in the case of some 

performance characteristics for the SDDS-PC.

Though KQ 1 addressed anxiety screening instruments in primary care populations with somatic 

symptoms, the samples in the studies identified were unselected and were seeing their primary 

care physician for a variety of complaints including routine followup. The instruments may 

perform differently in this setting when compared to a case-finding model where the same 

instrument is applied to patients with specific somatic complaints associated with a higher risk 

of having GAD or PD. We identified only one study that screened such patients, who were 

evaluated for palpitations.
3

Performance Characteristics of Self-report Instruments for Diagnosing 

Generalized Anxiety and Panic Disorders in Primary Care Evidence-based Synthesis Program

KQ 2. For questionnaires evaluated in KQ 1, which measures are most feasible 

to use in primary care settings? Specifically, what is the reading comprehension 

level, time required to complete, response format, and compatibility with 

telephone administration?

There was limited evidence addressing the feasibility of using these instruments in primary care. 

The evidence was qualitative and indirectly inferred from the primary studies.

The instruments were 3 to 11 questions in length and were at an easy to average reading level. 

Across the four studies reporting administration times, most patients completed the instrument in 

less than 2 minutes.

There was no evidence to assess the validity of these instruments for telephone administration 

though some trials have already used instruments like the Primary Care Evaluation of Mental 

Disorders (PRIME-MD) via telephone. None of the instruments have been studied specifically 

for responsiveness to change in symptoms status.

KQ 3. For questionnaires evaluated in KQ 1, do the performance characteristics 

vary by gender, race, age group, or setting?

Only one of the studies formally assessed differences in performance characteristics by race. 

When the Brief Panic Disorder Scale (BPDS) was administered to a biracial population, it 

performed better among Caucasians at the traditional cutoff of 10. The instrument was more 

specific among Caucasians and resulted in more false positives among African Americans. Thus, 

there is preliminary evidence that instruments might perform differently among different racial 

and ethnic groups.

None of the studies addressed differences in performance based on gender, age, or setting.

FUTURE RESEARCH

Based on study quality, operating characteristics, precision of the estimates, potential for 

assessing response to change, and other feasibility issues, the most promising instruments 

are: the panic module of the PHQ, the GAD-7 and the SDDS-PC. Future studies should focus 

on replicating the results of performance characteristics of these instruments, specifically in 

Veterans Affairs (VA) samples as we did not find any rigorous validation of any instruments 

in this review in the Veterans Health Administration (VHA) system. These studies should also 

incorporate questions of feasibility, such as time taken to complete, acceptability among patients, 

and sensitivity to change. Finally, results should be analyzed by race, gender, setting, and age to 

explore possible differences in performance of the instruments based on these variables.
4

Performance Characteristics of Self-report Instruments for Diagnosing 

Generalized Anxiety and Panic Disorders in Primary Care Evidence-based Synthesis Program

ABBREVIATIONS TABLE

BPDS Brief Panic Disorder Scale 

GAD generalized anxiety disorder

GRADE Grades of Recommendation, Assessment, Development, and Evaluation

KQ key question

PD panic disorder

PHQ Patient Health Questionnaire

PRIME-MD Primary Care Evaluation of Mental Disorders

QUADAS Quality Assessment of Diagnostic Accuracy Studies

SDDS-PC Symptom Driven Diagnostic System–Primary Care

VA Veterans Affairs

VHA Veterans Health Administration