Psychometric properties of nine scoring rules for the Clinician-Administered Posttraumatic Stress Disorder Scale.

The use of structured interviews that yield continuous measures of symptom severity has become increasingly widespread in the assessment of posttraumatic stress disorder (PTSD). To date, however, few scoring rules have been developed for converting continuous severity scores into dichotomous PTSD diagnoses. In this article, we describe and evaluate 9 such rules for the Clinician-Administered PTSD Scale (CAPS). Overall, these rules demonstrated good to excellent reliability and good correspondence with a PTSD diagnosis based on the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; DSM-II1—R; American Psychiatric Association, 1987). However, the rules yielded widely varying prevalence estimates in 2 samples of male Vietnam veterans. Also, the use of DSM-III-R versus DSM-IV criteria had negligible impact on PTSD diagnostic status. The selection of CAPS scoring rules for different assessment tasks is discussed.