Neighbourhood-level marginalization and avoidable mortality in Ontario, Canada: a population-based study

Objective To examine the impact of neighbourhood marginalization on avoidable mortality (AM) from preventable and treatable causes of death. Methods All premature deaths between 1993 and 2014 (N = 691,453) in Ontario, Canada, were assigned to quintiles of neighbourhood marginalization using the four dimensions of the Ontario Marginalization Index: dependency, ethnic concentration, material deprivation, and residential instability. We conducted two multivariate logistic regressions to examine the association between neighbourhood marginalization, first with AM compared with non-AM as the outcome, and second with AM from preventable causes compared with treatable causes as the outcome. All models were adjusted for decedent age, sex, urban/rural location, and level of comorbidity. Results A total of 463,015 deaths were classified as AM and 228,438 deaths were classified as non-AM. Persons living in the most materially deprived (OR, 1.24; 95% CI, 1.22 to 1.27) and residentially unstable neighbourhoods (OR, 1.13; 95% CI, 1.11 to 1.15) had greater odds of AM, particularly from preventable causes. Those living in the most dependent (OR, 0.91; 95% CI, 0.89 to 0.93) and ethnically concentrated neighbourhoods (OR, 0.93; 95% CI, 0.91 to 0.93) had lower odds of AM, although when AM occurred, it was more likely to arise from treatable causes. Conclusion Different marginalization dimensions have unique associations with AM. By identifying how different aspects of neighbourhood marginalization influence AM, these results may have important implications for future public health efforts to reduce inequities in avoidable deaths.