The association between neighbourhood marginalization and SARS-CoV-2 outcomes in patients presenting to emergency departments

Social and economic marginalizations have been associated with inferior health outcomes in Canada. Our objective was to describe the relationship between neighbourhood marginalization and COVID-19 outcomes among patients presenting to Canadian emergency departments (ED).

We conducted an observational study among consecutive COVID-19 patients recruited from 47 hospitals participating in the Canadian COVID-19 ED Rapid Response Network (CCEDRRN) between March 3, 2020, and July 24, 2022. We linked data with the Canadian Marginalization Index (CAN-Marg). We used multivariable, multi-level logistic regression models to understand the association between dimensions of neighbourhood marginalization, and severe COVID-19 and in-hospital mortality.

There were 55,588 eligible patients. Those from neighbourhoods with a higher proportion of recent immigrants (OR = 0.86 per unit increase [0.81, 0.92]), lower workforce participation (OR = 0.84 per unit increase [0.75, 0.94]), and more housing insecurity (OR = 0.81 per unit increase [0.77, 0.86]) were less likely to present to EDs with severe COVID-19. However, patients from materially marginalized neighbourhoods had increased odds of dying in hospital (OR = 1.19 per unit increase [95% CI 1.09, 1.30]) compared to patients from less materially marginalized neighbourhoods. Patients living in neighbourhoods with a higher proportion of recent immigrants (OR = 0.83 per unit increase [0.78, 0.91]) and lower participation in the workforce (OR = 0.77 per unit increase [0.66, 0.87]) experienced lower odds of dying.

Despite no association with severe COVID-19 at ED presentation, the only marginalization domain associated with in-hospital mortality was material deprivation. Our findings present insights on ED-seeking behaviour, hospital access, and care that population studies could not.