The validity of the PTSD checklist as a measure of symptomatic change in combat-related PTSD

Little research to date has examined the ability of self-report measures to assess changes in symptom severity and diagnostic status as a function of treatment. This study investigated the validity of the posttraumatic stress disorder (PTSD) checklist (PCL) as a measure of symptomatic change followi ng programmatic treatment. A sample of 97 Vietnam veterans with combat-rela ted PTSD was assessed using the clinician-administered PTSD scale (CAPS) an d the PCL prior to, and 9 months following, participation in a PTSD treatme nt program. Using the CAPS as the "gold standard" measure of PTSD symptomat ology, the PCL demonstrated high diagnostic accuracy pre- and posttreatment . However, significant variations in accuracy were evident in the ability o f the PCL to determine the presence and severity of individual symptoms at each time point. In addition, as symptoms improved from pre- to posttreatme nt, and approached the threshold criteria, the PCL demonstrated reductions in diagnostic accuracy. As a measure of overall symptomatic change, the PCL underrated improvement in comparison to the CAPS. The results supported th e use of an overall cut-off score of 50 on the PCL for a diagnosis, and an item score of 3 for symptom criterion, in this population. 2001 Elsevier Sc ience Ltd. (C) All rights reserved.