Validation of a screening instrument for post-traumatic stress disorder in a clinical sample of older adults.

OBJECTIVES To determine the diagnostic validity of the Post Traumatic Disorder Checklist (PCL) against the 'gold standard' of the Clinician Administered PTSD Scale (CAPS) in a clinical sample of older adults. METHODS A cross-sectional validation study: participants were patients (65 years and over) being treated for medical and/or psychiatric conditions in a hospital setting. Participants completed the PCL, measures of mood, cognition, physical health, alcohol use and the CAPS. A receiver operating characteristics curve was constructed to determine the optimal cut-point of the PCL. Analysis of variance was used to examine clinical differences between PTSD cases, sub-threshold cases and the remainder of the sample. RESULTS Using the recommended cut-point of 50, the PCL had a sensitivity of 0.40, specificity of 0.97 and positive predictive value of 0.57. However, these values changed to 0.90, 0.87 and 0.45, respectively, when the optimal cut-point of 36 was used. CONCLUSION With an adjusted cut-point the PCL is an acceptable and brief screening instrument for PTSD in older adults.