To identify baseline patient characteristics (i.e., demographic and psychological factors, military background) associated with better posttraumatic stress disorder (PTSD) treatment retention among veterans, we conducted a systematic review. After an electronic database search for studies of PTSD treatment in veterans, two reviewers independently screened the literature for eligibility, abstracted study-level information, and assessed risk of bias. As most studies used multivariate models to assess multiple potential predictors of retention simultaneously, the results were described narratively. The GRADE approach, adapted for prognostic literature, was used to assess the overall quality of evidence (QoE). In total, 19 studies reported in 25 publications met the inclusion criteria (n = 6 good quality, n = 9 fair quality, n = 4 poor quality). Definitions of treatment completion and dropout varied, and some studies lumped different therapy approaches together. Older age and higher treatment expectations were associated with better retention (moderate QoE). In 5 of 6 studies, baseline PTSD severity was not associated with retention, and the remaining study reported an association between better retention and more severe PTSD symptoms; the presence of more co-occurring psychiatric disorders was associated with better retention (moderate QoE). QoE was low or insufficient to support conclusions for any other characteristics due to inconsistent results, imprecision, potential publication bias, possible study population overlap, study limitations, or lack of studies. More research is needed regarding the associations between modifiable factors (e.g., motivation, barriers, expectations) and retention, and consistent definitions of treatment completion and minimally adequate treatment should be adopted throughout the field.
© 2021 International Society for Traumatic Stress Studies.