Nine RCTs in 18 publications were included in the review (n=unknown).
Alcohol initiation (seven RCTs): Overall, family interventions significantly reduced levels of alcohol initiation compared to control groups (OR 0.71, 95% CI 0.54 to 0.94). There was evidence of statistical heterogeneity for this analysis (p<0.001; I2=78.6%). When one outlying study was removed from the analysis the results remained significant and heterogeneity was reduced (I2=0%).
Last-month alcohol use (three RCTs): There were no significant differences between family interventions and control groups for last month alcohol use. There was no evidence of statistical heterogeneity (p=0.170), although the I2 test was 40.4%.
Frequency of alcohol use (five RCTs): Overall, family interventions were significantly more effective in reducing frequency of alcohol use than control groups (MD -0.25, 95% CI -0.37 to -0.12) at follow-up. There was no evidence of statistical heterogeneity. Subgroup analyses reported no difference to the results when one study that reported the greatest effect was removed from the analysis.
Analyses over follow-up times (three RCTs): Overall analysis found no statistically significant differences for alcohol initiation at three follow-up points (12 to 18 months, 24 to 30 months and 36 to 48 months). However, after one study described as an outlier was excluded from the analysis, family intervention programs were found to be significantly more effective at 30 months (OR 0.49, 95% CI 0.30 to 0.80) and 48 months (OR 0.53, 95% CI 0.38 to 0.75), but not at 18 months (OR 0.71, 95% CI 0.25 to 2.01) compared with controls. Details of other subgroup analyses were reported.
There was no evidence of publication bias for any of the analyses.