School-based interventions effective in preventing multiple risk behaviours

School‐based programmes provided universally without consideration of individual risk were likely to be effective in preventing tobacco use, alcohol use and physical inactivity (moderate‐quality evidence) and might also be beneficial in relation to illicit drug use (low‐quality evidence). Evidence was less certain for the effects of such multiple-risk-behaviour interventions for cannabis use, sexual-risk behaviours and unhealthy diet. Individual and family‐level interventions seemed to have little or no benefit in relation to the outcomes considered. Included studies had a combined intervention and follow-up period of ≥6 months.