Longitudinal associations of local cigarette prices and smoking bans with smoking behavior in the multi-ethnic study of atherosclerosis

Background: Few studies have examined associations of geographically proximal cigarette prices with within-person changes in smoking outcomes or assessed interactions between cigarette prices and smoking bans. Methods: We linked neighborhood cigarette prices (inflation-adjusted) at chain supermarkets and drug stores and bar/restaurant smoking ban policies to cohort participants (632 smokers from the Multi-Ethnic Study of Atherosclerosis, 2001-2012, baseline mean age 58 years) using geocoded retailer and participant addresses. We used fixed-effects models to investigate associations of within-person changes in price and ban exposures with within-person changes in five smoking outcomes: current smoking, heavy (≥10 cigarettes) smoking, cessation, relapse, and intensity (average number of cigarettes smoked per day, natural log transformed). We assessed intensity associations among all smokers, and heavy (≥10 cigarettes per day) and light (<10) baseline smokers. Finally, we tested interactions between cigarette price and bans. Results: A $1 increase in price was associated with a 3% reduction in risk of current smoking (adjusted risk ratio [aRR]: 0.97; 95% confidence interval [CI] = 0.93, 1.0), a 7% reduction in risk of heavy smoking (aRR: 0.93; CI = 0.87, 0.99), a 20% increase in risk of smoking cessation (aRR: 1.2; CI = 0.99, 1.4), and a 35% reduction in the average number of cigarettes smoked per day by heavy baseline smokers (ratio of geometric means: 0.65; CI = 0.45, 0.93). We found no association between smoking bans and outcomes, and no evidence that price effects were modified by the presence of bans. Conclusions: Results underscore the importance of local prices, but not hospitality smoking bans, in influencing older adults' smoking behaviors.