Twenty-nine RCTs were included: 16 (n=1,073) of children and adolescents and 13 (n=636) of adults. Of these, 10 and 11 RCTs respectively were included in the quantitative analysis.
Only 2 studies were classified as having a low risk of bias.
Glycaemic control.
The pooled estimate for children and adolescents (based on 10 RCTs) was small to moderate (SMD -0.35, 95% CI: -0.66, -0.04, p=0.03); this translated into an absolute reduction of 0.48% (95% CI: 0.05, 0.91). The test for heterogeneity was statistically significant (p=0.002). When family therapy for children and adolescents was pooled separately, the effect size was slightly larger.
The pooled estimate for adults (based on 11 RCTs) was small (SMD -0.17, 95% CI: -0.45, 0.10, p=0.22); this translated into an absolute reduction of 0.22% (95% CI: -0.13, 0.56). The test for heterogeneity was statistically significant (p=0.02). When CBT for adults was pooled separately, the effect size was smaller.
Psychological distress.
The pooled estimate for children and adolescents (based on 4 RCTs) was moderate (SMD -0.46, 95% CI: -0.83, -0.10, p=0.013). The pooled estimate for adults was small (SMD -0.25, 95% CI: -0.51, 0.01, p=0.059). The test for heterogeneity was not statistically significant.