Treatment of PTSD in the military health system: Which patients receive evidence based psychotherapy?

The goal of this study was to identify patient-level factors associated with receiving evidence-based psychotherapy (EBP) for posttraumatic stress disorder (PTSD) in the military health system (MHS). We used machine learning models (LASSO, RFE, Elastic Net) to examine predictors of initiation (at least one session) and minimally adequate dosage (three sessions in 90 days or eight sessions in 14 weeks) of EBP defined as prolonged exposure, cognitive processing therapy, or eye movement desensitization and reprocessing therapy. Participants (N = 3,459) were diagnosed with PTSD and receiving behavioral health services at one of eight military treatment facilities between July 2018 and December 2021. Predictors included patient demographics, treatment experiences (e.g., session spacing), and clinical characteristics (e.g., comorbidities). Results showed that 51.3% of patients initiated EBP, 25.7% received three sessions in 90 days, and 7.5% received eight sessions in 14 weeks. The strongest predictors of EBP receipt were the total number of sessions, military service branch, and comorbid mood disorder. Specifically, those who received a greater total number of all psychotherapy sessions were more likely to initiate and receive a minimally adequate dosage of EBP. EBP receipt was lower through the Navy and Army compared to the Air Force, and among those with comorbid mood disorder. Findings emphasize the influence of treatment experiences in EBP receipt and point to the need for further research on provider- and system-level determinants of EBP receipt. Identifying predictors can inform efforts to improve the quality of PTSD care in the MHS, ensuring access to effective treatments.