Most of the reviews from the Cochrane Tobacco Addiction Group look at ways to help smokers to quit, but some of them explore how to stop people from starting to smoke in the first place. One of their updated reviews from February 2015 does this for family-based programmes that aim to prevent smoking by children and adolescents. The lead author, Roger Thomas from the University of Calgary in Canada tells us what they found and begins by posing and answering the questions that drove the review.