The effectiveness of routinely delivered cognitive behavioural therapy for obsessive-compulsive disorder: a benchmarking study.

Objectives: There is often difficulty in generalizing the results of randomized controlled trials (RCTs) to routine clinical practice given the rigid design features of such studies. The purpose of this study is to describe the effectiveness of routinely delivered, formulation-based cognitive behavioural therapy (CBT) within a publicly funded clinic for adults with obsessive-compulsive disorder (OCD) and offer a comparison against the outcomes achieved in efficacy studies for the same population.

Method: Practice-based prospective study. Routine data collected from a National Health Service out-patient clinic for adult clients with OCD is benchmarked against the findings of RCTs. The comparison RCTs were identified using a systematic review methodology.

Results: The mean (95% confidence interval) change in Yale-Brown Obsessive Compulsive Scale score pre- to post-therapy in the Sheffield clinic was 10.2 (7.1 - 13.3), which compares well with changes of 11.4 (10.5 - 12.2) for exposure and response prevention trials, 12.9 (11.2 - 14.7) for cognitive therapy trials, and 10.6 (8.5 - 12.8) for CBT trials. The Sheffield results fell within the benchmarks derived from the included RCTs.

Conclusion: These results indicate that CBT for adults with OCD delivered outside the constraints of a clinical trial is equivalently effective but that this conclusion should be tested further on a larger group of patients.