A narrative analysis of the included studies was undertaken. Meta-analyses were not performed because they were judged inappropriate due to heterogeneity in the methods and outcomes of the included studies. Primary study methods were appraised to evaluate the potential for confounding and bias, with particular attention paid to selection, attrition, recall and reporting biases. With regards to confounding, the level of control for important background psychosocial and familial risk factors for alcohol problems including socioeconomic status, family history of alcohol problems, mental health issues or other early evidence of behavioural problems was assessed.8 17
