The validity and diagnostic efficiency of the Davidson Trauma Scale in military veterans who have served since September 11th, 2001

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Abstract

The present study examined the psychometric properties and diagnostic efficiency of the Davidson Trauma Scale (DTS), a self-report measure of posttraumatic stress disorder (PTSD) symptoms. Participants included 158 U.S. military veterans who have served since September 11, 2001 (post-9/11). Results support the DTS as a valid self-report measure of PTSD symptoms. The DTS demonstrated good internal consistency, concurrent validity, and convergent and divergent validity. Diagnostic efficiency was excellent when discriminating between veterans with PTSD and veterans with no Axis I diagnosis. However, although satisfactory by conventional standards, efficiency was substantially attenuated when discriminating between PTSD and other Axis I diagnoses. Thus, results illustrate that potency of the DTS as a diagnostic aid was highly dependent on the comparison group used for analyses. Results are discussed in terms of applications to clinical practice and research.

Introduction

Self-report measures are valuable tools for clinicians and researchers, as they are quick and cost-effective methods for assessing symptoms associated with mental illness. In the last two decades, several self-report measures of posttraumatic stress disorder (PTSD) have been developed (see Brewin, 2005; Norris & Hamblen, 2004; for reviews). Concurrently, there has been a growing appreciation for the reality that for a measure to have utility, it is essential that support for its validity has been demonstrated (Hunsley & Mash, 2005). As evidence accumulates for the negative impact of PTSD on overall health (Beckham et al., 1998, Dohrenwend et al., 2007; Taft, Stern, King, & King, 1999), family adjustment (Jordan et al., 1992) and health care costs (Walker et al., 2003) the need for brief and valid measures of PTSD symptoms has become clear.

Prior studies have validated various PTSD symptom questionnaires for use with several targeted groups, including breast cancer patients (Andrykowski, Cordova, Studts, & Miller, 1998), crime victims (Wohlfarth, van den Brink, Winkel, & ter Smitten, 2003), Vietnam-era combat veterans (Forbes, Creamer, & Biddle, 2001), female veterans in primary care (Dobie et al., 2002; Lang, Laffaye, Satz, Dresselhaus, & Stein, 2003) and older adults in primary care (Cook, Elhai, & Areán, 2005). Replications such as these are important, as a symptom scale may take on different properties in different populations (Bossuyt et al., 2003, Brewin, 2005). For example, Blanchard et al. (1996) found that a score of 44 or higher on the PCL Checklist was most effective at identifying PTSD while minimizing false positives in a sample of motor vehicle accident and sexual assault victims. In contrast, Lang et al. (2003), using the same measure, found that a score in the range of 28–30 was most effective in detecting PTSD in female veterans who visited a primary care clinic.

Unfortunately, many populations that are at high-risk for trauma exposure do not have adequately-validated measures available. For example, in spite of the increasing need for valid PTSD screening instruments for returning military service personnel (Hoge et al., 2004), no self-report measure of PTSD has yet been validated with veterans who have served since September 11th, 2001 (post-9/11). It is estimated that 35% of OIF veterans will access mental health services in the year after returning home, and 5–20% will meet criteria for PTSD (Hoge, Auchterlonie, & Milliken, 2006; Hoge et al., 2004). As there are now several empirically-supported treatments for PTSD (American Psychiatric Association, 2004; Bisson & Andrew, 2005; Department of Veterans Affairs & Department of Defense, 2004), there is compelling incentive to validate screening tools for the identification of PTSD in high-risk groups, such as military personnel and veterans.

Diagnostic tests are most efficient when a group identified as having the condition is compared to an equal number of those that exhibit none of the clinical characteristics of the condition, e.g. healthy controls. It is important to consider that clinical characteristics of the comparison group may have significant effects on the efficiency of the test in question, and thus their generalizability (Coyne & Thompson, 2007; Streiner, 2003). For example, individuals with Major Depressive Disorder endorse many of the symptoms that are found in PTSD (e.g., poor concentration, sleep difficulties, and anhedonia), and thus tend to score higher on PTSD symptom questionnaires than healthy controls (Shalev et al., 1998). In effect, a score that is very efficient when discriminating between PTSD and healthy controls may be less efficient in discriminating between PTSD and individuals with other presenting problems. The latter scenario more approximates conditions in a mental health clinic, in which most patients will be in distress and the clinician is faced with the often challenging task of differential diagnosis (cf. Hankin, Spiro, Miller, & Kazis, 1999). Unfortunately, prior studies have rarely described or assessed the clinical characteristics of their comparison groups. Thus, the literature provides little evidence for the diagnostic efficiency of PTSD symptom questionnaires in a mental health setting.

The purpose of the current study was to examine the validity and diagnostic efficiency of the Davidson Trauma Scale (DTS; Davidson, Book, et al., 1997) in a group of veterans who served after September 11th, 2001. The DTS is a self-report measure of the 17 PTSD symptoms as described in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; American Psychiatric Association, 2000). As a diagnostic tool, Davidson, Book, et al. (1997) demonstrated that the DTS performed well at discriminating 67 individuals with PTSD from 62 without PTSD (area under the curve [AUC] = 0.88, S.E. = 0.02) using a semi-structured interview (SCID; Spitzer, Williams, Gibbon, & First, 1990) as the reference standard. A DTS score of 40 was recommended as the optimal cut-point for accurate classification of those with or without PTSD (efficiency = 0.83). This cut-point correctly classified 69% of individuals with PTSD (sensitivity = 0.69) and 95% of those who did not have PTSD (specificity = 0.95).

No previous studies have examined the psychometric properties of the DTS in veterans who have served post-9/11. Like most PTSD screening measures, the ability of the DTS to discriminate between those with PTSD and other psychiatric disorders is unknown. Therefore, the current study tested the ability of the DTS to discriminate between veterans with PTSD and two comparison groups: (1) veterans with no Axis I diagnosis and (2) veterans without PTSD but with a current diagnosis of another Axis I disorder.

Section snippets

Participants and procedures

The sample consisted of 226 volunteer participants in the Mid-Atlantic Mental Illness Research, Education and Clinical Center (MIRECC) Recruitment Database for the Study of Post-Deployment Mental Health. Participants were veterans who have served in the United States Armed Forces since September 11, 2001. About half (53%) of the participants had been stationed in a region of conflict in support of Operation Enduring Freedom or Operation Iraqi Freedom. Participants were recruited from four

Sample characteristics

Gender, race, and other demographic data for the participants are presented in Table 1. Diagnostic interviews using the SCID-I/P revealed that 71 participants (45%) met criteria for an Axis I disorder, with about half of those (39, 55%) meeting criteria for PTSD. Of those with PTSD, 25 (64%) met criteria for a secondary Axis I disorder, consistent with the high levels of comorbidity described in other studies (Magruder et al., 2005). The most common diagnoses accompanying PTSD were Major

Discussion

The present study examined the validity and diagnostic efficiency of the DTS (Davidson, Book, et al., 1997) in a sample of veterans who have served since September 11th, 2001. Posttraumatic stress disorder is a relatively prevalent condition among these veterans, and there is a strong need for valid assessment tools. Brief self-report questionnaires, such as the DTS, can provide a considerable aid to the clinician and researcher in identifying those who are experiencing symptoms of PTSD.

Acknowledgements

Preparation of this manuscript was in part supported by Office of Research and Development Clinical Science, Department of Veterans Affairs, K24DA016388, K23MH073091, 2R01CA081595, and R21DA019704 and HL54780. The views expressed in this presentation are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs or the National Institutes of Health. We would like to acknowledge the contributions of the OIF/OEF Registry Workgroup (Ms. Kimberly Green and

References (53)

  • M.A. Andrykowski et al.

    Posttraumatic stress disorder after treatment for breast cancer: prevalence of diagnosis and use of the PTSD Checklist-Civilian Version (PCL-C) as a screening instrument

    Journal of Consulting and Clinical Psychology

    (1998)
  • J.C. Beckham et al.

    Health status, somatization, and severity of posttraumatic stress disorder in Vietnam combat veterans with posttraumatic stress disorder

    American Journal of Psychiatry

    (1998)
  • J. Bisson et al.

    Psychological treatment of post-traumatic stress disorder (PTSD)

    Cochrane Database of Systematic Reviews

    (2005)
  • D.D. Blake et al.

    A clinician rating scale for assessing current and lifetime PTSD: the CAPS-1

    The Behavior Therapist

    (1990)
  • P.M. Bossuyt et al.

    The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration

    Annals of Internal Medicine

    (2003)
  • C.R. Brewin

    Systematic review of screening instruments for adults at risk of PTSD

    Journal of Traumatic Stress

    (2005)
  • J.M. Cook et al.

    Psychometric properties of the PTSD Checklist with older primary care patients

    Journal of Traumatic Stress

    (2005)
  • J. Davidson

    Davidson Trauma Scale (DTS)

    (1996)
  • J. Davidson et al.

    Davidson Trauma Scale (DTS): normative scores in the general population and effect sizes in placebo-controlled SSRI trials

    Depression & Anxiety

    (2002)
  • J.R.T. Davidson et al.

    Assessment of a new self-rating scale for post-traumatic stress disorder

    Psychological Medicine

    (1997)
  • J.R.T. Davidson et al.

    Structured interview for PTSD (SIP): psychometric validation for DSM-IV criteria

    Depression & Anxiety (1091–4269)

    (1997)
  • Department of Veterans Affairs & Department of Defense. (2004). VA/DoD Clinical Practice Guideline for the Management...
  • L.R. Derogatis

    SCL-90-R: administration, scoring, and procedures manual

    (1994)
  • B.P. Dohrenwend et al.

    Continuing controversy over the psychological risks of Vietnam for U.S. veterans

    Journal of Traumatic Stress

    (2007)
  • J.D. Elhai et al.

    Examining the uniqueness of frequency and intensity symptom ratings in posttraumatic stress disorder assessment

    Journal of Nervous and Mental Disease

    (2006)
  • M.B. First et al.

    Structured clinical interview for DSM-IV axis I disorders—patient edition (SCID-I/P, Version 2.0)

    (1994)
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