B - 132 Validation of the PCL-5 Symptom Severity Scale Embedded Symptom Validity Index in a Cross-Cultural Forensic Sample

Abstract Objective Three embedded symptom validity indices were recently created for the PTSD Checklist for DSM-5 (PCL-5). The first, the PCL-5 Symptom Severity Scale (PSS), is derived from the PCL-5 total score, and preliminary findings have indicated its effectiveness in research and clinical samples. Our aim was to cross-validate this validity index in a cross-cultural forensic sample. Method Examinees were Macedonian and Kosovar contractors (N = 79) previously employed at military bases in Afghanistan and Iraq. Examinees underwent defense psychological examinations between 2018 and 2023 related to pursuit of federal workers compensation claims for PTSD. Testing was performed with translated instruments and administered with assistance from certified interpreters. Two sets of analyses were conducted in this study. In the first, examinees were categorized as valid or invalid responders based on their Trauma Symptom Inventory-II Atypical Response Scale (ATR) scores. In the second, validity status was categorized based on a more conservative criterion of failing 2+ validity tests. Results Receiver operating characteristic analyses were used to determine optimal cutoff scores and classification accuracy statistics for the PSS. The area under the curve was acceptable (0.77) in both analyses. When categorizing invalidity with the ATR, a PSS cutoff of 64 resulted in 95% specificity and 33% sensitivity. When categorizing invalidity by failure of 2+ validity tests, the PSS cutoff could be adjusted to 62 resulting in 90% specificity and 46% sensitivity. Conclusion Results of the current study are in line with those from previous research. These findings extend the utility of the PSS to a cross-cultural forensic sample.