A quasi-randomized group trial of a brief alcohol intervention on risky single occasion drinking among secondary school students.

Objectives: To show the effectiveness of a brief group alcohol intervention. Aims of the intervention were to reduce the frequency of heavy drinking occasions, maximum number of drinks on an occasion and overall weekly consumption.

Methods: A cluster quasi-randomized control trial (intervention n = 338; control n = 330) among 16- to 18-year-old secondary school students in the Swiss Canton of Zürich.