Factor Structure and Multi-Group Measurement Invariance of Posttraumatic Stress Disorder Symptoms Assessed by the PCL-5

Abstract

The Posttraumatic Stress Disorder Checklist (PCL) is widely used in research and clinical settings to assess posttraumatic stress disorder (PTSD) symptomatology, including to examine PTSD symptoms/severity across diverse groups. However, the validity of these studies depends on the degree to which the PCL captures a conceptually equivalent construct of PTSD across the compared groups. This study examined the factor structure and invariance of PTSD as assessed by the PCL for DSM-5 (PCL-5) across a sample of trauma-exposed students (n = 412) and trauma-exposed participants recruited online through Amazon’s Mechanical Turk (MTurk; n = 346) platform. Participants from both samples completed the Stressful Life Events Screening Questionnaire (exposure to traumatic events) and the PCL-5. Using confirmatory factor analysis (CFA), we examined the factor structure of the DSM-5 and five alterative models of PTSD separately in both samples. We then tested measurement invariance of the DSM-5 and the optimal model of PTSD across these samples. All PTSD models fit the data well; however, the Hybrid model provided a significantly better fit for both samples. Both the Hybrid and DSM-5 models of PTSD demonstrated invariance for item mappings on factors (configural), factor loadings (metric), intercepts (scalar), and error variances (residual). Our findings support the stability, applicability, and meaningful comparisons of the PCL-5 assessed DSM-5 and Hybrid model factors across samples of trauma-exposed students and MTurk participants.