Background: Evidence for an association between
neighborhood disadvantage and smoking is mixed and mainly based on
cross-sectional studies. To shed light on the causality of this
association, we examined whether change in neighborhood socioeconomic
disadvantage is associated with within-individual change in smoking
behaviors.

Methods: The study population comprised participants
of the Finnish Public Sector study who reported a change in their
smoking behavior between surveys in 2008/2009 and 2012/2013. We linked
participants’ residential addresses to a total population database on
neighborhood disadvantage with 250 × 250-m resolution. The outcome
variables were changes in smoking status (being a smoker vs. not) as
well as the intensity (heavy/moderate vs. light smoker). We used
longitudinal case-crossover design, a method that accounts for
time-invariant confounders by design. We adjusted models for
time-varying covariates.

Results: Of the 3,443 participants, 1,714 quit, while
967 began to smoke between surveys. Smoking intensity increased among
398 and decreased among 364 participants. The level of neighborhood
disadvantage changed for 1,078 participants because they moved
residence. Increased disadvantage was associated with increased odds of
being a smoker (odds ratio of taking up smoking 1.23 [95% confidence
interval: 1.2, 1.5] per 1 SD increase in standardized national
disadvantage score). Odds ratio for being a heavy/moderate (vs. light)
smoker was 1.14 (95% confidence interval: 0.85, 1.52) when disadvantage
increased by 1 SD.

Conclusions: These within-individual results link an
increase in neighborhood socioeconomic disadvantage, due to move in
residence, with subsequent smoking behaviors.