Factors associated with PTSD symptom improvement among Iraq and Afghanistan veterans receiving evidenced-based psychotherapy.

BACKGROUND:Despite availability of evidence-based psychotherapies (EBPs) for posttraumatic stress disorder (PTSD), not all veterans who initiate EBPs experience benefit. Better understanding factors associated with clinically significant improvement can help ameliorate care. METHODS:A cohort of Iraq and Afghanistan War veterans who initiated an EBP was identified (N = 32,780) with ≥1 post-deployment psychotherapy visit at the Veterans Health Administration from 10/2001-6/2017, a post-deployment PTSD diagnosis, and ≥2 PTSD symptom measures. We used random-effects logistic regression to assess whether patient-level, diagnostic, and treatment factors were associated with achieving symptom improvement. RESULTS:Increased odds of PTSD symptom improvement were seen in women (OR = 1.19; 95% CI: 1.09--1.29), those who initiated EBP within a year of engaging in mental healthcare compared with the delayed EBP group (OR = 1.20; 95% CI: 1.14--1.28), those who completed at least 8 EBP sessions in 16 weeks (OR = 1.23; 95% CI:1.11--1.36), those who received PE only (vs. CPT or both; OR = 2.23; 95% CI: 1.86--2.68) or CPT individual therapy only (vs. CPT group or both; OR = 1.34; 95% CI: 1.22--1.48), and those with a drug dependence diagnosis (OR = 1.24; 95% CI: 1.11--1.39). Decreased odds of improvement were seen in Black veterans (OR=0.75; 95% CI: 0.69--0.81) and those with service-connected disability (OR = 0.61; 95% CI: 0.52--0.71). LIMITATIONS:Diagnoses were from medical charts and not confirmed with gold standard assessment tools; we only included veterans with at least two PTSD measurements, which may cause bias. CONCLUSION:Modifiable factors associated with PTSD improvement (timing, dose, and modality) can be used to improve EBP outcomes.