Impact of banning smoking in cars with children on exposure to second-hand smoke: a natural experiment in England and Scotland

England banned smoking in cars carrying children in 2015 and Scotland in 2016. We used survey data from 3 years for both countries (N England =3483–6920, N Scotland =232–319) to assess effects of the English ban using logistic regression within a difference-in-differences framework. Among children aged 13–15 years, self-reported levels of regular exposure to smoke in cars for Scotland were 3.4% in 2012, 2.2% in 2014 and 1.3% in 2016 and for...