3
ASSESSMENT INSTRUMENTS

Although an optimal evaluation of a patient for PTSD consists of a face-to-face interview by a mental health professional trained in diagnosing psychiatric disorders, several instruments are available to facilitate the diagnosis and assessment of posttraumatic stress disorder (PTSD). These include screening tools, diagnostic instruments, and trauma and symptom severity scales. For example, there are brief screening tools, such as the 4-item Primary Care PTSD Screen, developed by the Department of Veterans Affairs National Center for Posttraumatic Stress Disorder; self-report screening instruments, such as the Posttraumatic Diagnostic Scale; and structured or semi-structured interviews, such as the Clinician-Administered PTSD Scale (CAPS), the Structured Clinical Interview for DSM-IV (SCID), the Diagnostic Interview Schedule for DSM-IV (DIS-IV), and the Composite International Diagnostic Interview (CIDI), all of which might be used prior to or as a complement to the clinical interview. These instruments are discussed below. Such measures are used most frequently in research settings, some might be used clinically to provide additional sources of documentation, and others might be given to veterans at a health facility prior to their first interview with health professional. Screening tools can be useful in initiating a conversation about exposure to traumatic events or possible PTSD symptoms. However, as noted in Briere (2004) “no psychological test can replace the focused attention, visible empathy, and extensive clinical experience of a well-trained and seasoned trauma clinician.”



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment 3 ASSESSMENT INSTRUMENTS Although an optimal evaluation of a patient for PTSD consists of a face-to-face interview by a mental health professional trained in diagnosing psychiatric disorders, several instruments are available to facilitate the diagnosis and assessment of posttraumatic stress disorder (PTSD). These include screening tools, diagnostic instruments, and trauma and symptom severity scales. For example, there are brief screening tools, such as the 4-item Primary Care PTSD Screen, developed by the Department of Veterans Affairs National Center for Posttraumatic Stress Disorder; self-report screening instruments, such as the Posttraumatic Diagnostic Scale; and structured or semi-structured interviews, such as the Clinician-Administered PTSD Scale (CAPS), the Structured Clinical Interview for DSM-IV (SCID), the Diagnostic Interview Schedule for DSM-IV (DIS-IV), and the Composite International Diagnostic Interview (CIDI), all of which might be used prior to or as a complement to the clinical interview. These instruments are discussed below. Such measures are used most frequently in research settings, some might be used clinically to provide additional sources of documentation, and others might be given to veterans at a health facility prior to their first interview with health professional. Screening tools can be useful in initiating a conversation about exposure to traumatic events or possible PTSD symptoms. However, as noted in Briere (2004) “no psychological test can replace the focused attention, visible empathy, and extensive clinical experience of a well-trained and seasoned trauma clinician.”

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment DIAGNOSTIC INTERVIEWS A health professional might use an unstructured interview to elicit information from a patient about symptoms related to each of the diagnostic criteria for PTSD. He or she might also use a structured or semi-structured diagnostic interview such as the CAPS, SCID, PTSD Symptom Scale-Interview Version (PSS-I), the Structured Interview for PTSD (SIP), the DIS-IV, or the CIDI. The use of those instruments can inform professional judgment in a clinical setting, but they are more commonly used in epidemiologic and treatment outcomes research. The CAPS is a semi-structured interview, developed by the Department of Veterans Affairs National Center for Post-Traumatic Stress Disorder. The CAPS should be administered by a trained health professional and can be used to determine whether a patient meets the DSM-IV diagnostic criteria for PTSD. It has the advantage of assessing the array of PTSD symptoms, as well as their severity (frequency and intensity), but it cannot be used to determine the presence of comorbid psychiatric disorders. The CAPS contains 34 questions, 17 of which measure symptom frequency and 17 measure symptom intensity. The CAPS generally takes at least 40 to 60 minutes to administer (Foa and Tolin 2000). The SCID is a widely used structured clinical interview for psychiatric disorders that contains a PTSD-specific module with 19 items. Like the CAPS, the SCID-PTSD module has questions related to each of the DSM-IV diagnostic criteria; patients’ responses are listed as present, absent, or subthreshold. The SCID, like the CAPS, should be administered by a trained health professional. Unlike the CAPS, the SCID can be used to identify comorbid psychiatric disorders (Briere 2004); that is important because comorbid psychiatric disorders are common in PTSD patients. The SCID does not assess the severity of PTSD symptoms; the determination of whether a symptom passes a severity threshold is left to clinical judgment or further testing with a symptom-severity scale.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment The PSS-I is a semi-structured interview that also assesses PTSD symptoms according to DSM-IV and their severity (Foa and Tolin 2000). It contains 17 questions that correspond to each of the DSM criteria and participants’ responses are rated by a health professional from zero (not at all) to 3 (5 or more times per week/very much). It shows good agreement with the CAPS and the SCID in diagnosing PTSD. The PSS-I may be slightly better at detecting actual PTSD, whereas the CAPS is more accurate at ruling out false positives (Foa and Tolin 2000). This interview was developed for and has been tested on civilian populations with known trauma history, but has not been tested on combat veterans. The PSS-I has the advantage of taking only about 20 to 30 minutes to administer. The SIP is a 19-item questionnaire that is also based on the DSM-IV criteria for PTSD (Davidson et al. 1989). Like the PSS-I, it identifies both PTSD symptoms and their severity and has two additional items on survivor and behavior guilt. The SIP has been tested on combat veterans with good correlation to other measures of PTSD but not to measures of combat exposure (Riggs and Keane 2006). The SIP can take 10 to 30 minutes to administer by a trained interviewer. The DIS-IV is a structured interview for DSM-IV diagnoses designed to be administered by trained lay interviewers and is used in psychiatric research to assess psychiatric disorders (Friedman 2003). The CIDI is another structured diagnostic interview that can be used to assess many psychiatric disorders, but, as an international instrument, it is based on the International Criteria for Disease rather than the DSM. Like the DIS-IV, the CIDI can be administered by carefully trained lay interviewers for research purposes. The DIS-IV and the CIDI have both been used in major US population studies, such as the Epidemiologic Catchment Area program and the National Comorbidity Study, respectively (Helzer et al. 1987; Kessler et al. 1997). Both the DIS-IV and the CIDI can also be administered by clinicians. Those instruments aid in the diagnosis of PTSD and other disorders as well, but they do not assess symptom severity. Structured interviews that were developed specifically for diagnosis of PTSD, such as the CAPS, will probably take longer to administer (an hour or more) but yield useful information, for example,

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment information regarding the intensity and frequency of symptoms, rather than simply whether the symptoms are present. Some of the diagnostic instruments, such as the PSS-I and SIP, can be used to determine not only whether a patient has PTSD symptoms but also symptom severity, comorbid psychiatric disorders, and whether a patient is malingering. There are also several self-report instruments that can be used to help document symptoms and traumatic exposures. These include the Posttraumatic Diagnostic Scale (Foa et al. 1997), the Davidson Trauma Scale (Davidson et al. 1997), and the Detailed Assessment of Posttraumatic Stress (DAPS) (Briere 2004). Each of the instruments determines what symptoms of PTSD are present, as well as their frequency and intensity. The DAPS, which has 104 items, also assesses a broad range of psychologic functions and reactions. Although self-report instruments have utility for screening people with possible PTSD and in research settings, they should not substitute for a comprehensive diagnostic interview. SELF-REPORTS OF TRAUMATIC EVENTS Several self-report instruments have been developed to document a veteran’s exposure to a war-zone traumatic event. Like the structured and semi-structured diagnostic interviews, they can be used in a clinical setting but have had more use as research tools. Table 3.1 lists some representative instruments that have been developed to assess exposure to traumatic events associated with military service. They might be used in conjunction with a diagnostic interview to document details of traumatic exposures. The instruments’ function is to obtain greater detail about an exposure than the health professional might initially be able to elicit from the patient. The selection of an instrument depends on the reported war-zone trauma.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment TABLE 3.1 Self-Report Measures of Exposure to Military-Related Potentially Traumatic Events Scale Name Number of Items References Abusive Violence Scale 5 Hendrix and Schumm 1990 Combat Exposure Index 7 Janes et al. 1991 Combat Exposure Scale 7 Keane et al. 1989 Deployment Risk and Resiliency Inventory 201 King et al. 2003 Graves Registration Duty Scale 24 Sutker et al. 1994 Military Stress Scale 6 Watson et al. 1988 Sexual Experiences Questionnaire—Department of Defense 22 Fitzgerald et al. 1999 Vietnam Era Stress Inventory—Specific Stressor Subscale 46 Wilson et al. 1980 War Events Scale 84 Unger et al. 1998 War Zone Stress Scale 72 King et al. 1995a Women’s Wartime Stressor Scale 27 Wolfe et al. 1993 SOURCE: Adapted with permission from Wilson et al. 2004. NONDIAGNOSTIC ASSESSMENT AND SCREENING INSTRUMENTS Several validated questionnaires are available to describe PTSD symptom severity in military personnel. Like the traumatic-event exposure instruments, they are self-report instruments that might be used as adjuncts to diagnostic interview instruments such as the CAPS or a comprehensive clinical diagnostic interview. Some of the instruments, such as the PTSD Checklist (PCL), the Posttraumatic Diagnostic Scale (Foa et al. 1997), and Davidson Trauma Scale (Davidson et al. 1997) discussed above, assess DSM-IV symptoms of PTSD as well as symptom severity; others, such as the Keane PTSD Scale of the Minnesota Multiphasic Personality Inventory (MMPI-PK), assess associated features of PTSD. With the PCL, patients use a 1–5 scale to rate the

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment frequency and intensity of their symptoms. The version developed for the military (PCL-M), which was validated on 123 male veterans, has a test-retest reliability of 96% (Blanchard et al. 1996; Weathers et al. 1991). The Mississippi Scale for Combat-Related PTSD has a test-retest reliability of 97% (Keane et al. 1988). The Impact of Event Scale-Revised (IES-R) is a widely used, 22-item, self-report instrument that measures a person’s response to a traumatic stressor. The revised version more closely conforms with the DSM-IV criteria for PTSD. The severity of each symptom, during the past week, is rated by the respondent; the scale takes approximately 10 minutes to complete (Riggs and Keane 2006). The IES (not revised), the MMPI-PK, and the Mississippi Scale for Combat-related PTSD were used in the National Vietnam Veterans Readjustment Study. The Los Angeles Symptom Checklist (King et al. 1995b) has also been used to measure PTSD symptoms in Vietnam veterans; it has a test-retest reliability of 90% for all 43 items. Table 3.2 lists some of the symptom-severity instruments that have been used in research settings. It must be emphasized that the instruments for assessing symptom severity do not diagnose PTSD and should not be used in lieu of a comprehensive clinical interview. Their utility is in eliciting details about symptoms that might not be provided by a patient during a clinical interview and they might provide an additional source of documentation. In general, screening instruments are helpful for identifying people who might have a disease but are not very useful for assessing disorder progression, prognosis, or treatment efficacy. Screening instruments might be of value when a population is too large for each person to be assessed individually; a screening instrument might be used to help identify people who indicate that they have some PTSD symptoms and who would then receive a full diagnostic assessment by a health professional.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment TABLE 3.2 Symptom-Severity Instruments for PTSD Scale Number of Items References PTSD Checklist 17 Blanchard et al. 1996 Mississippi Scale for Combat-Related PTSD 35 Keane et al. 1988; McFall et al. 1990 Impact of Event Scale-Revised 22 Horowitz et al. 1979 MMPI-PK 49 Keane et al. 1984 Self-Rating Inventory for PTSD 22 Hovens et al. 2002 Posttraumatic Diagnostic Scale 49 Foa et al. 1997 Davidson Trauma Scale 17 Davidson et al. 1997 War-Zone Related PTSD subscale of the Symptom Checklist 90-Revised 25 Derogatis and Cleary 1977 Los Angeles Symptom Checklist 43 King et al. 1995b Recently, the VA National Center for Post-Traumatic Stress Disorder has developed a four-question screening tool, the Primary Care PTSD Screen (Prins et al. 2003), that can be used by primary-care physicians and other health professionals (the questions are available at: http://www.ncptsd.va.gov/facts/disasters/fs_screen_disaster.html). The Primary Care PTSD Screen has a sensitivity of 78% and a specificity of 87% (Friedman 2006). Patients answering yes to three or more of the questions should be considered for further evaluation for PTSD. Other self-report screening instruments for PTSD have been developed and used with community trauma patients, however, none have been validated on combat veterans. Among these are: a short screening scale containing seven questions keyed to the DSM-IV criteria for PTSD (Breslau et al. 1999); the 17-item PTSD Symptom Scale Self-Report that was developed to identify PTSD in patients with substance use disorder (Coffey et al. 1998); the Screen for Posttraumatic Stress Symptoms that assesses PTSD in patients who do not report exposure to a traumatic event (Carlson 2001); and the Psychiatric Diagnostic

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment Screening Questionnaire, a 125-item questionnaire with a PTSD subscale (Zimmerman and Mattia 2001). CONCLUSION Several screening tools and diagnostic instrument are available to assist the clinician in making a PTSD diagnosis, documenting a traumatic event, and in assessing symptom severity. However, none of those instruments alone can provide a comprehensive diagnosis and assessment of a PTSD patient or replace a health professional trained in diagnosing psychiatric disorders. While assessment instruments are helpful, they are used primarily in research settings. REFERENCES Blanchard EB, Jones-Alexander J, Buckley TC, Forneris CA. 1996. Psychometric properties of the PTSD Checklist (PCL). Behaviour Research and Therapy 34(8):669–673. Breslau N, Peterson EL, Kessler RC, Schultz LR. 1999. Short screening scale for DSM-IV posttraumatic stress disorder. American Journal of Psychiatry 156(6):908–911. Briere J. 2004. Psychological Assessment of Adult Posttraumatic States: Phenomenology, Diagnosis, and Measurement. 2nd ed. Washington, DC: American Psychological Association. Carlson EB. 2001. Psychometric study of a brief screen for PTSD: Assessing the impact of multiple traumatic events. Assessment 8(4):431–441. Coffey SF, Dansky BS, Falsetti SA, Saladin ME, Brady KT. 1998. Screening for PTSD in a substance abuse sample: Psychometric properties of a modified version of the PTSD Symptom Scale Self-Report. Posttraumatic stress disorder. Journal of Traumatic Stress 11(2):393–329.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment Davidson J, Smith R, Kudler H. 1989. Validity and reliability of the DSM-III criteria for posttraumatic stress disorder. Experience with a structured interview. Journal of Nervous & Mental Disease 177(6):336–341. Davidson JR, Book S, Colket J, Tupler L, et al. 1997. Assessment of a new self-rating scale for post-traumatic stress disorder. Psychological Medicine 27(1):153–160. Derogatis LR, Cleary PA. 1977. Factorial invariance across gender for the primary symptom dimensions of the SCL-90. British Journal of Social and Clinical Psychology 16(4):347–356. Fitzgerald LF, Magley VJ, Drasgow F, Walso CR. 1999. Measuring sexual harassment in the military: The SEQ-DoD. Military Psychology 11(3):243–263. Foa EB, Tolin DF. 2000. Comparison of the PTSD Symptom Scale-Interview Version and the Clinician-Administered PTSD scale. Journal of Traumatic Stress 13(2):181–191. Foa EB, Cashman L, Jaycox L, Perry K. 1997. The validation of a self-report measure of posttraumatic stress disorder: The Posttraumatic Diagnostic Scale. Psychological Assessment 9(4):445–451. Friedman MJ. 2003. Post Traumatic Stress Disorder: The Latest Assessment and Treatment Strategies. Kansas City, MO: Compact Clinicals. Friedman MJ. 2006. Posttraumatic stress disorder among military returnees from Afghanistan and Iraq. American Journal of Psychiatry 163(4):586–593. Helzer JE, Robins LN, McEvoy L. 1987. Post-traumatic stress disorder in the general population. Findings of the epidemiologic catchment area survey. New England Journal of Medicine 317(26):1630–1634. Hendrix C, Schumm W. 1990. Reliability and validity of the Abusive Violence Scale. Psychological Reports 66(3 Pt 2):1251–1258. Horowitz M, Wilner N, Alvarez W. 1979. Impact of Event Scale: A measure of subjective stress. Psychosomatic Medicine 41(3):209–218.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment Hovens JE, Bramsen I, van der Ploeg HM. 2002. Self-rating inventory for posttraumatic stress disorder: Review of the psychometric properties of a new brief Dutch screening instrument. Perceptual & Motor Skills 94(3 Pt 1):996–1008. Janes GR, Goldberg J, Eisen SA, True WR. 1991. Reliability and validity of a combat exposure index for Vietnam era veterans. Journal of Clinical Psychology 47(1):80–86. Keane TM, Malloy PF, Fairbank JA. 1984. Empirical development of an MMPI subscale for the assessment of combat-related posttraumatic stress disorder. Journal of Consulting and Clinical Psychology 52(5):888–891. Keane TM, Caddell JM, Taylor KL. 1988. Mississippi Scale for Combat-Related Posttraumatic Stress Disorder: Three studies in reliability and validity. Journal of Consulting and Clinical Psychology 56(1):85–90. Keane TM, Fairbank JA, Caddell JM, Zimering RT, et al. 1989. Clinical evaluation of a measure to assess combat exposure. Psychological Assessment 1(1):53–55. Kessler RC, Anthony JC, Blazer DG, Bromet E, Eaton WW, Kendler K, Swartz M, Wittchen HU, Zhao S. 1997. The US National Comorbidity Survey: overview and future directions. Epidemiologia e Psichiatria Sociale 6(1):4–16. King DW, King LA, Gudanowski DM, Vreven DL. 1995a. Alternative representations of war zone stressors: relationships to posttraumatic stress disorder in male and female Vietnam veterans. Journal of Abnormal Psychology 104(1):184–195. King DW, King LA, Vogt DS. 2003. Manual for the Depoloyment Risk and Resilience Inventory (DRRI): A Collection of Measures for Studying Deployment Related Experiences in Military Veterans. Boston, MA: National Center for PTSD. King LA, King DW, Leskin G, Foy DW. 1995b. The Los Angeles Symptom Checklist: A self-report measure of posttraumatic stress disorder. Assessment 2:1–17.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment McFall ME, Smith DE, Roszell DK, Tarver DJ, Malas KL. 1990. Convergent validity of measures of PTSD in Vietnam combat veterans. American Journal of Psychiatry 147(5):645–648. Prins A, Ouimette P, Kimerling R, Cameron RP, Hugelshofer DS, Shaw-Hegwer J, Thrailkill A, Gusman FD, Sheikh JI. 2003. The primary care PTSD screen (PC-PTSD): Development and operating characteristics. Primary Care Psychiatry 9(1):9–14. Riggs D, Keane TM. 2006. Assessment strategies in the anxiety disorders. In: Rothbaum BO, Editor. Pathological Anxiety: Emotional Processing in Etiology and Treatment of Anxiety. New York: Guilford. Pp. 91–114. Sutker PB, Uddo M, Brailey K, Vasterling JJ, Errera P. 1994. Psychopathology in war-zone deployed and nondeployed Operation Desert Storm troops assigned graves registration duties. Journal of Abnormal Psychology 103(2):383–390. Unger WS, Gould RA, Babich M. 1998. The development of a scale to assess war-time atrocities: The War Events Scale. Journal of Traumatic Stress 11(2):375–383. Watson CG, Kucala T, Manifold V, Vassar P, Juba M. 1988. Differences between posttraumatic stress disorder patients with delayed and undelayed onsets. Journal of Nervous & Mental Disease 176(9):568–572. Weathers FW, Huska J, Keane TM. 1991. The PTSD Checklist Military Version (PCL-M). Boston, MA: National Center for PTSD. Wilson JP, Keane TM. 2004. Assessing Psychological Trauma and PTSD, 2nd Ed. New York: Guilford Press. Wilson JP, Krause GE. 1980. The Vietnam Era Stress Inventory. Cleveland, OH: Cleveland State University. Wolfe J, Brown PJ, Furey J, Levin KB. 1993. Development of a Wartime Stressor Scale for Women. Psychological Assessment. 5(3):330–335. Zimmerman M, Mattia JI. 2001. The Psychiatric Diagnostic Screening Questionnaire: Development, reliability and validity. Comprehensive Psychiatry 42(3):175–189.

OCR for page 29
Posttraumatic Stress Disorder: Diagnosis and Assessment This page intially left blank