Impact of surgery after injury on SDNN and posttraumatic stress disorder development over two years.

This study examined the modifying effects of surgery status on the association between the Standard Deviation of NN Intervals (SDNN) of the heart rate variability and the post-traumatic stress disorder (PTSD) development. Participants with physical injury were recruited from a trauma center and followed for two years. Baseline assessment included SDNN and surgery status. Socio-demographic and clinical covariates were collected. PTSD was diagnosed at 3, 6, 12, and 24 months post-injury using the Clinician-Administered PTSD Scale for DSM-5. Logistic regression analyses were performed. Among 538 participants, 58 (10.8%) developed PTSD during the study, with prevalence rates of 8.4% at 3 months, 6.5% at 6 months, 4.7% at 12 months, and 2.5% at 24 months. A significant modifying effect was found that lower SDNN were significantly associated with PTSD in non-surgical patients but not in surgical patients, with significant interaction terms. This pattern was observed from 3 to 12 months but not at 24 months. Surgery-dependent associations between SDNN and PTSD development were observed, highlighting the need for tailored PTSD prevention strategies considering SDNN and surgery status.