Group therapy for people with bulimia nervosa: systematic review and meta-analysis

Background. Approximately 25% of people with bulimia nervosa (BN) who undertake therapy are treated in groups. National guidelines do not discriminate between group and individual therapy, yet each has potential advantages and disadvantages and it is unclear how their effects compare. We therefore evaluated how group therapy for BN compares with individual therapy, no treatment, or other therapies, in terms of remission from binges and binge frequency. Method. We performed a systematic review and meta-analysis of randomized controlled trials of group therapies for BN, following standard guidelines. Results. A total of 10 studies were included. Studies were generally small with unclear risk of bias. There was low-quality evidence of a clinically relevant advantage for group cognitive behavioural therapy (CBT) over no treatment at therapy end. Remission was more likely with group CBT versus no treatment [relative risk (RR) 0.77, 95% confidence interval (CI) 0.62-0.96]. Mean weekly binges were lower with group CBT versus no treatment (2.9 v. 6.9, standardized mean difference=-0.56, 95% CI -0.96 to -0.15). One study provided low-quality evidence that group CBT was inferior compared with individual CBT to a clinically relevant degree for remission at therapy end (RR 1.24, 95% CI 1.03-1.50); there was insufficient evidence regarding frequency of binges. Conclusions. Conclusions could only be reached for CBT. Low-quality evidence suggests that group CBT is effective compared with no treatment, but there was insufficient or very limited evidence about how group and individual CBT compared. The risk of bias and imprecise estimates of effect invite further research to refine and increase confidence in these findings.