The average remission rate across trials (n=10) for CBT, non-active comparison conditions, and active comparison conditions were 57%, 9%, and 23% respectively. A random effects meta-analysis identified a large effect for CBT relative to comparison conditions (RR=3.42, 95% CI: 2.11, 5.53, z=5.00, p<0.001) with little heterogeneity [Q(9)=13.96, p=0.12, I2=35.52%] (Figure 4). The NNT for CBT remission was three. Visual inspection of the funnel plot and Egger’s test for bias indicated that publication bias was present (t=3.10, p=0.01). When Duval and Tweedie’s trim-and-fill method was applied, six studies were trimmed and CBT still exhibited a large significant effect (RR=2.15, 95%CI: 1.31, 3.54). The analog-to-ANOVA revealed a significant difference between active comparison trials (RR=2.05) and non-active comparison trials (RR=5.40) [Q(1)=6.93, p=0.008]. Given the significant difference between comparison conditions, the summary effect was recalculated with active comparison trials removed. Results identified a large effect (RR=5.40, 95% CI: 2.86, 10.22, z=5.18, p<0.001) with minimal heterogeneity [Q(6)=6.43, p=0.38, I2=6.63%] among non-active comparison trials. For active comparison trials, a large effect was observed (RR=2.05, 95% CI: 1.46, 2.88, z=4.16, p<0.001), with minimal heterogeneity [Q(2)=0.39 p=0.83, I2=0%].
