Differential PTSD Symptom Cluster Profiles by Trauma Exposure Modality in Community-Dwelling Vietnamese Older Adults

<ns3:p>Background PTSD in community-dwelling older adults remains under-recognized in post-conflict, low- and middle-income countries such as Vietnam, where mental health services have predominantly targeted direct trauma survivors. Whether distinct PTSD symptom cluster profiles emerge across different exposure modalities has not been examined. Methods This cross-sectional secondary analysis used data from the Vietnam Health and Aging Study (VHAS, 2021–2022). Of 296 community-dwelling adults aged ≥60 with documented trauma exposure, 147 with complete Criterion A subtype data were classified as any direct exposure (n = 130) and indirect-only exposure (n = 17). PCL-5 cluster scores were compared using Mann-Whitney U tests. Logistic regression adjusted for cumulative trauma burden examined whether exposure modality predicted clinical PTSD (PCL-5 ≥ 11). Results Total PCL-5 scores did not differ significantly between the indirect-only and any direct exposure groups (mean 8.82 ± 12.98 vs. 5.10 ± 9.68; U = 997.5, p = 0.467). In exploratory cluster-level comparisons, only Avoidance (Cluster C) differed significantly (mean 1.35 ± 2.09 vs. 0.56 ± 1.53; U = 826.5, p = 0.013). The proportion meeting clinical PTSD threshold was higher in the indirect-only group (41.2% vs. 17.7%; OR = 3.26, 95% CI: 1.12–9.45). After adjustment for cumulative trauma burden, the association persisted (AOR = 3.41, 95% CI: 1.16–10.00, p = 0.025). Conclusions Among community-dwelling older Vietnamese adults, indirect-only trauma exposure was associated with elevated avoidance symptoms (Cluster C) and approximately threefold higher odds of clinical PTSD relative to direct exposure, independent of cumulative trauma burden. Total severity did not differ, suggesting exposure modality may shape symptom structure rather than overall burden. These findings warrant cautious interpretation given the small indirect-only subgroup (n = 17), wide confidence intervals, and cross-sectional design; replication in larger prospective samples is needed before clinical recommendations can be made.</ns3:p>