Preventing adolescent alcohol use: effects of a two-year quasi-experimental community intervention intensifying...

To determine the effect on adolescent alcohol use of a community intervention combining intensified formal control (restricting retail supply) and informal control (restricting social supply). Intervention effects on intermediate intervention goals were investigated. Analyses for different age groups were performed.

A longitudinal quasi-experimental design (baseline at 2008, plus two yearly post-measurements) was used, including one intervention and one matched-comparison community in The Netherlands. We assessed outcomes by observing 1,368 Dutch adolescents aged 13-15 years at baseline. Main dependent variables were weekly drinking status and progression into drunkenness among weekly drinkers. Additional dependent variables were formal control intermediate intervention goals (frequency of alcohol purchases and perceived ease of purchasing alcohol) and informal control intermediate intervention goals (frequency of alcohol-specific rules and parental alcohol supply).

Survival analyses showed no significant reduction in the risk of drinking weekly for adolescents in the intervention region; however, the risk of progressing into drunkenness was reduced by 15% (p = .04) for adolescents drinking weekly. No intervention effects on the intermediate intervention goals were found among 14- and 15-year-olds. The intervention had a positive effect on two of four intermediate intervention goals (i.e., parental alcohol supply and alcohol-specific rules) among 13-year-olds.

A combined formal and informal community intervention package is associated with a reduced risk of progressing into drunkenness among drinking adolescents. Interventions focusing on discouraging drinking below a certain age might cause a greater increase in the frequency of purchasing alcohol once reaching this age.