Thirteen trials were included in the review (n=958 patients). There was a discrepancy in the number of participants enrolled between text and table; the number used in this abstract is calculated from data in table 2. Follow-up assessments ranged from one to 12 months.
A greater improvement in post-treatment primary outcome measures (Hedges' g=1.08 95% CI 0.69 to 1.46; 13 studies; n=675 patients) and secondary outcome measures (Hedges' g=0.77, 95% CI 0.53 to 1.01; 13 trials; n=666 patients) was found with prolonged exposure therapy compared with control conditions.
Similar results were found for primary outcomes when grouped by type of control (waiting list Hedges' g=1.52, 95% CI 1.12 to 1.90; psychological placebo, Hedges' g=0.65, 95% CI 0.29 to 1.01).
No significant difference was found when prolonged exposure therapy was compared with other active treatments (Hedges' g=-0.07, 95% CI -0.42 to 0.28; six trials; n=262 patients).
At follow-up, a greater improvement on primary outcome measures (Hedges' g=0.68, 95% CI 0.27 to 1.10; seven trials; n=348 patients) and secondary outcome measures (Hedges' g=0.41, 95% CI 0.03 to 0.78; seven trials; n=368 patients) was found for prolonged exposure therapy compared with control conditions.
No significant effect of any moderator was found.
No evidence of publication bias was found.