What does best evidence tell us about the efficacy of group cognitive–behavioral therapy for obsessive–compulsive disorder? Protocol for a systematic review and meta-analysis

Group cognitive-behavioral therapy (GCBT) may be a cost-effective alternative modality for the treatment of obsessive-compulsive disorder (OCD). In the last decade, a great deal of research has been conducted to evaluate the efficacy of GCBT for OCD. Despite promising results, studies have produced inconclusive evidence. The current paper will present a protocol for a systematic review and meta-analysis of randomized controlled trials assessing the efficacy of GCBT compared with control conditions or individual CBT at post-treatment and follow-up on OCD symptoms, anxiety, depression, obsessive beliefs, quality of life, and functioning. Another aim will be to compare the levels of early drop out from GCBT relative to control conditions or individual CBT. Finally, the study will investigate potential outcome moderators (age, sex, OCD severity, severity of concurrent depression, comorbid personality disorders, duration of OCD symptom onset, duration of treatment, intensity of treatment, generation cohort, methodological quality, and publication date). A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines will be conducted using random-effects meta-analyses. Online databases and trial registries will be searched, the corresponding authors will be contacted, and conference proceedings and relevant journals will be hand-searched to locate published and unpublished studies. Risk of bias will be assessed using the Cochrane Collaboration's tool.