Abstract
INTRODUCTION: This study examines whether smoke-free laws are differentially associated with youth smoking outcomes by parental education, race/ethnicity, sex, and college plans in a U.S. METHODS: This study assessed the relationships between smoke-free laws in workplaces and hospitality venues (restaurants/bars) and past 30-day smoking participation, first cigarette initiation, and daily smoking initiation within a repeated cross-sectional sample of 8th, 10th, and 12th graders from the Monitoring the Future study. Data were collected between 2001 and 2018 and were analyzed in 2020-2021. Grade-stratified Poisson models were used to calculate prevalence ratios and average marginal effects, incorporating interaction terms to examine differential associations across groups. RESULTS: Hospitality smoke-free laws were significantly associated with lower probabilities of smoking participation in all grades as well as with first cigarette and daily smoking initiation in 8th and 10th grade. Workplace smoke-free laws were associated with lower probabilities of smoking participation among 10th and 12th graders as well as with first cigarette and daily smoking initiation among 10th graders. Average marginal effects ranged from -0.4 percentage points (hospitality laws and daily smoking initiation in 8th and 10th grades) to -2.2 percentage points (workplace laws and smoking participation in 10th grade). Associations between smoke-free laws and a lower probability of smoking participation were most pronounced among students who definitely planned to attend college. Other instances of effect modification suggested more pronounced associations for students who were female and from high-SES households; however, relationships varied by grade. CONCLUSIONS: Smoke-free laws were associated with reduced smoking among youth; however, associations varied by grade, sex, parental education, and college plans.