To estimate the impact of tobacco‐21 laws on smoking among young adults who are likely to smoke, and consider potential social multiplier effects.
Quasi‐experimental, observational study using new 2016–17 survey data.
A total of 1869 18–22‐year‐olds who have tried a combustible or electronic cigarette.
Intervention and comparators
Tobacco‐21 laws raise the minimum legal sales age of cigarettes to 21 years. Logistic regressions compared the association between tobacco‐21 laws and smoking among 18–20‐year‐olds with that for 21–22‐year‐olds. The older age group served as a comparison group that was not bound by these restrictions, but could have been affected by correlated factors. Age 16 peer and parental tobacco use were considered as potential moderators.
Self‐reported recent smoking (past 30‐day smoking) and current established smoking (recent smoking and life‐time consumption of at least 100 cigarettes).
Exposure to tobacco‐21 laws yielded a 39% reduction in the odds of both recent smoking [odds ratio (OR) = 0.61; 95% confidence interval (CI) = 0.42, 0.89] and current established smoking (OR = 0.61; 95% CI = 0.39, 0.97) among 18–20‐year‐olds who had ever tried cigarettes. This association exceeded the policy’s relationship with smoking among 21–22‐year‐olds. For current established smoking, the tobacco‐21 reduction was amplified among those whose closest friends at age 16 used cigarettes (OR = 0.50; 95% CI = 0.29, 0.87), consistent with peer effects moderating the policy’s impact on young adult smoking.
Tobacco‐21 laws appear to reduce smoking among 18–20‐year‐olds who have ever tried cigarettes.