Psychometric properties of the German version of the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) in routine clinical settings: a multi-trait/multi-method study in civilians and military personnel

Abstract Background The Clinician-Administered PTSD Scale (CAPS-5) is a structured diagnostic interview developed for diagnosing post-traumatic stress disorder (PTSD). To ensure compliance with PTSD inclusion criteria, an initial study investigated the psychometric properties and factorial structure of the German version of CAPS-5 using data collected previously. The present study’s objective was to validate the robustness of the psychometric properties of the German CAPS-5 by assessing its validity within a routine clinical context. Methods A total of 288 participants were recruited for the study. The validity of the German CAPS-5 was assessed using a multi-trait/multi-method design. Additionally, the study explored internal consistency, test-retest reliability, interrater reliability, and the interview’s diagnostic accuracy. Ultimately, a cut-off score was determined through receiver operating characteristics curve (ROC) analyses. Results The study demonstrated good to excellent internal consistency, test-retest reliability, interrater reliability, construct validity, and diagnostic accuracy for the German CAPS-5. Furthermore, the study established a cut-off score of ≥ 40 for the German CAPS-5 sum score. Discussion The German CAPS-5 emerged as a structured diagnostic interview exhibiting good to excellent psychometric properties. The findings indicated solid convergent validity of the German CAPS-5; however, further research is warranted to investigate its divergent validity. Trial registration: DRKS00015325 (https://www.drks.de)