A comparison of the CAPS-5 and PCL-5 to assess PTSD in military and veteran treatment-seeking samples

Resick, P. A., Straud, C. L., Wachen, J. S., LoSavio, S. T., Peterson, A. L., McGeary, D. D., Young-McCaughan, S., Taylor, D. J., & Mintz, J., for the STRONG STAR Consortium and the Consortium to Alleviate PTSD

Background: This study was an examination of the puzzling ﬁnding that people assessed for symptoms of posttraumatic stress disorder (PTSD) consistently score higher on the self-report PTSD Checklist for DSM-5 (PCL-5) than the Clinician-Administered PTSD Scale for DSM-5 (CAPS- 5). Both scales purportedly assess PTSD severity with the same number of items, scaling, and scoring range, but diﬀerences in scores between measures make outcomes diﬃcult to decipher.
Objective: The purpose of this study was to examine several possible psychometric reasons for the discrepancy in scores between interview and self-report.
Method: Data were combined from four clinical trials to examine the baseline and posttreatment
assessments of treatment-seeking active duty military personnel and veterans.
Results: As in previous studies, total scores were higher on the PCL-5 compared to the CAPS-5 at
baseline and posttreatment. At baseline, PCL-5 scores were higher on all 20 items, with small to large diﬀerences in eﬀect size. At posttreatment, only three items were not signiﬁcantly diﬀerent. Distributions of item responses and wording of scale anchors and items were examined as possible explanations of the diﬀerence between measures. Participants were more likely to use the full range of responses on the PCL-5 compared to interviewers.
Conclusions: Suggestions for improving the congruence between these two scales are discussed.
Administration of interviews by trained assessors can be resource intensive, so it is important
that those assessing PTSD severity are aﬀorded conﬁd nce in the equivalence of their assessment of
PTSD regardless of the assessment method used.