Longitudinal psychometric validation and measurement invariance of the PTSD checklist for DSM-5 (PCL-5)

Despite the adoption of the four-factor model of posttraumatic stress disorder (PTSD) in the DSM-5, very few studies have provided longitudinal examinations of the temporal stability of the PTSD Checklist for DSM-5 (PCL-5), particularly in East Asian contexts. In addition, its factorial structure and validity have been a subject of considerable debate, with accumulating evidence suggesting that alternative models may better capture the heterogeneity of PTSD symptoms. To address these gaps, the present study evaluated the psychometric properties of the Traditional Chinese version of the PCL-5 (TC-PCL-5) across three timepoints (N = 412 at Time 1, 232 at Time 2, and 132 at Time 3) in a community sample of Hong Kong adults, testing both the four- and six-factor structures of the PCL-5. Internal consistency of the scale remained stable across all three waves of the study $(T1:\omega =0.97$; $T2:\omega =0.98$; $T3:\omega =0.98)$. Intraclass correlation analyses revealed good test–retest reliability. Confirmatory factor analyses supported both factorial structures at each timepoint. Results demonstrated configural, metric, and scalar invariance across all three waves and indicated that the underlying factor structure, item loadings, and intercepts remained stable over time, with the six-factor structure showing a slightly better fit.