Psychometric properties and validity of the German version of the Post-Traumatic Diagnostic Scale for DSM-5 (PDS-5)

Abstract

Background: The availability of psychometrically sound instruments for the assessment of Post-Traumatic Stress Disorder (PTSD) is indispensable for clinical and scientific work with individuals suffering from trauma-related distress. Objective: The aim of the present study was to translate the Post-Traumatic Diagnostic Scale for DSM-5 (PDS-5) into German and to evaluate its psychometric properties as well as convergent, discriminant, and factorial validity. Method: The authorized German translation of the PDS-5 was completed by 270 patients admitted to specialized outpatient trauma clinics. Of these, 57.8% completed the PDS for a second time (mean time between assessments was 12.0 days). In order to examine convergent and discriminant validity of the PDS-5, the Post-traumatic Stress Disorder Checklist for DSM-5 as well as Patient Health Questionnaire subscales assessing depression (PHQ-9), somatization (PHQ-15), and Generalized Anxiety Disorder (GAD-7) were applied. Results: The PDS-5 total score showed excellent internal consistency (α = .91) and re-test reliability (rho = .84). Convergent validity was supported by a strong correlation with the total score of the Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5; rho = .91). Correlations with Patient Health Questionnaire subscales of depression (rho = .81), anxiety (rho = .72), and somatization (rho = .65) were significantly lower (all p < .001) indicating discriminant validity of the PDS-5. Confirmative Factor Analysis did not result in a clear preference for one of the tested models. Defining a diagnostic cut-off value of ≥36 based on ROC analysis resulted in high sensitivity (.92) and specificity (.96) compared to a probable PTSD diagnosis according to the PCL-5. Conclusions: In summary, our results indicate that the German PDS-5 translation provides valid and reliable information concerning both PTSD severity and diagnosis.