Meta-analysis of dropout in treatments for posttraumatic stress disorder.

OBJECTIVE: Many patients drop out of treatments for posttraumatic stress disorder (PTSD); some clinicians believe that trauma-focused treatments increase dropout. METHOD: We conducted a meta-analysis of dropout among active treatments in clinical trials for PTSD (42 studies; 17 direct comparisons). RESULTS: The average dropout rate was 18%, but it varied significantly across studies. Group modality and greater number of sessions, but not trauma focus, predicted increased dropout. When the meta-analysis was restricted to direct comparisons of active treatments, there were no differences in dropout. Differences in trauma focus between treatments in the same study did not predict dropout. However, trauma-focused treatments resulted in higher dropout compared with present-centered therapy (PCT), a treatment originally designed as a control but now listed as a research-supported intervention for PTSD. CONCLUSION: Dropout varies between active interventions for PTSD across studies, but variability is primarily driven by differences between studies. There do not appear to be systematic differences across active interventions when they are directly compared in the same study. The degree of clinical attention placed on the traumatic event does not appear to be a primary cause of dropout from active treatments. However, comparisons of PCT may be an exception to this general pattern, perhaps because of a restriction of variability in trauma focus among comparisons of active treatments. More research is needed comparing trauma-focused interventions to trauma-avoidant treatments such as PCT.