Residential environments and smoking behaviour patterns among young adults: A prospective study using data from the Interdisciplinary Study of Inequalities in Smoking cohort.

Young adults have the highest prevalence of smoking among all age groups. Studies have shown associations between presence/density of tobacco retail and presence of smoker accommodation and smoking prevalence. However, little is known about their potential to influence different smoking patterns including initiation, maintenance, or cessation. This is important because smoking behaviour patterns in young adults may be subject to ongoing changes. Moreover, smoking pattern determinants may be different to those of smoking prevalence, and feature-pattern associations may be scale-dependent, requiring the consideration of different analytical spatial units. We examined associations between prospectively-measured smoking behaviour patterns and presence/density of tobacco retail, and presence of smoker accommodation facilities across 2 nested spatial units in Montreal, Canada. Data were from 18 to 25 year-old Montreal residents who had participated in the Interdisciplinary Study of Inequalities in Smoking cohort both at baseline in 2011-2012 and follow-up in 2014 and resided in the same area at follow-up. 2-year smoking behaviour patterns were assessed for 2 cohorts based on participants' smoking status at baseline. Associations were examined using multilevel logistic models. Young adults who were smokers at baseline residing in areas with higher local-level presence of tobacco retail were less likely to quit smoking (i.e.: to be non-smokers for fewer than 2 years). Higher presence of smoker accommodation was not associated with smoking patterns at any scale. Findings provide evidence of scale-specific associations between residential environment features and smoking behaviour patterns in young adults, which may point to specific exposure-outcome processes underlying these associations.