Less dropout from prolonged exposure sessions prescribed at least twice weekly: A meta-analysis and systematic review of randomized controlled trials.

Trauma-focused psychotherapies, such as prolonged exposure (PE), are strongly recommended to treat posttraumatic stress disorder due to their effects in reducing symptoms. However, such therapies may also suffer from high dropout rates. To investigate how clients might benefit from trauma-focused therapy while minimizing dropout, we conducted a meta-analysis of 1,508 adults from 35 randomized controlled trials (RCTs) of outpatient PE programs to evaluate treatment frequency as a predictor of dropout. When an RCT prescribed PE sessions at least twice weekly compared to less frequently, the dropout rate was significantly lower at 21.0%, 95% CI [13.9%, 30.4%], compared to 34.0%, 95% CI [28.9%, 39.4%], OR = 0.52, 95% CI [0.30, 0.89], p = .018. It was not possible to draw causal conclusions, as only one RCT compared two PE treatment frequencies head-to-head. Nonetheless, the findings remained significant after controlling for study characteristics. These data invite reconsideration of the common practice of weekly psychotherapy in favor of twice-weekly sessions in standard outpatient treatment.