Inequality in COVID-19 mortality in Quebec associated with neighbourhood-level vulnerability domains

Abstract

Objectives: We measured disparities in COVID-19 mortality associated with increasing vulnerability to severe outcomes of infectious disease at the neighbourhood level to identify domains for prioritization of public interventions. Methods: In this retrospective ecological study, we calculated COVID-19 mortality rate ratios (RR) comparing neighbourhoods with the greatest vulnerability relative to lowest vulnerability using the five domains from the COVID-19 vulnerability index for Quebec using hospital data from the first year of the pandemic and vulnerability levels from 13,182 neighbourhoods. We estimated the attributable fraction to assess disparities in COVID-19 mortality associated with vulnerability. Domains covered biological susceptibility, sociocultural characteristics, socioeconomic characteristics, and indoor and outdoor risk factors for exposure to SARS-CoV-2. Results: Vulnerable neighbourhoods accounted for 60.7% of COVID-19 deaths between March 2020 and February 2021. Neighbourhoods with biological susceptibility accounted for 46.1% and indoor exposure for 44.6% of deaths. Neighbourhoods with socioeconomic vulnerability experienced 23.5%, outdoor exposure 14.6%, and sociocultural vulnerability 9.0% of deaths. Neighbourhoods with high relative vulnerability had 4.66 times greater risk of COVID-19 mortality compared with those with low vulnerability (95%CI 3.82-5.67). High vulnerability in the biological (RR 3.33; 95%CI 2.71-4.09), sociocultural (RR 1.50; 95%CI 1.27-1.77), socioeconomic (RR 2.08; 95%CI 1.75-2.48), and indoor (RR 3.21; 95%CI 2.74-3.76) exposure domains were associated with elevated risks of mortality compared with the least vulnerable neighbourhoods. Outdoor exposure was unassociated with mortality (RR 1.17; 95%CI 0.96-2.43). Conclusion: Public intervention to protect vulnerable populations should be adapted to focus on domains most associated with COVID-19 mortality to ensure addressing local needs.