Geographic concentration of SARS-CoV-2 cases by social determinants of health in metropolitan areas in Canada: a cross-sectional study

Abstract

he COVID-19 epidemic in Canada has varied in size and trajectory across provinces and large cities. 1,2 At the national level 3 and within regions, 4,5 the burden of confirmed SARS-CoV-2 cases and severe COVID-19 outcomes has fallen disproportionately on socially and economically marginalized communities. 6 Social determinants of health refer to nonmedical factors influencing health outcomes, and structural determinants encompass cultural norms, policies and institutions that generate social stratification and determine socioeconomic position. 7,8 In Canada and elsewhere, data have consistently highlighted the importance of determinants such as household size and density, work in essential services and structural racism (measured by proxy) in the relative risk of COVID-19. [9][10][11][12][13][14][15][16][17] Understanding the factors associated with geographic patterns of transmission within cities can help identify the populations and, specifically, the contexts with the greatest risks. Geographic analyses can enable better allocation of resources, tailoring of policies and implementation of context-specific

Herd immunity thresholds for SARS-CoV-2 estimated from unfolding epidemics

“…We saw the same consistency in our previous analysis of England and Scotland (Gomes et al 2022). We find this unsurprising given the amply reported evidence of socioeconomic determinants as key drivers of heterogeneity in infectious diseases (e.g., Millett et al 2020, Xia et al 2022). Societal changes may not significantly impact our inferences unless major inversions in socioeconomic gradients had occurred which is unimaginable in the time scale of a pandemic.…”

COVID-19 Cases Among Congregate Care Facility Staff by Neighborhood of Residence and Social and Structural Determinants: Observational Study

“…Many congregate facilities experienced outbreaks, with residents experiencing a 3- to 5-fold higher test positivity rate than the community-dwelling population [ 1 , 3 , 4 , 7 , 8 ]. Meanwhile, data on the community-dwelling population suggested a consistent pattern of geographic clustering of cases with 50% of cases occurring in approximately 25% of the population and disproportionately affecting those residing in neighborhoods that are less affluent and with a higher proportion of essential workers [ 9 , 10 ].…”

“…Surveillance data on COVID-19 cases offer an opportunity to examine the pattern of cases among facility staff and other health care workers (HCWs) against community cases and neighborhood disparities. Lorenz curves, Gini coefficients, and the Hoover index, traditionally used as measurements of economic inequality [ 12 , 13 ], have been used in a range of health care research to measure health inequality [ 14 , 15 ]; for example, these measurements of health inequality have been recently applied in the context of the COVID-19 pandemic [ 10 , 16 ]. We sought to adapt Lorenz curves, Gini coefficients, and the Hoover index to compare the concentration of cases using neighborhood-level rates and neighborhood-level social and structural determinants across 3 mutually exclusive subgroups: community, facility staff (LTCHs, retirement homes, shelters), and other HCWs not working in congregate settings (eg, only working in hospitals).…”

Extending the impact of CMAJ

“…Most recently, the COVID-19 pandemic has underscored how the poor, the marginally housed, immigrants, racialized people and people with disabilities were, and continue to be, at highest risk of illness and death in Canada. 6 But it is now time to move beyond highlighting this problem over and over, and work on testing and implementing innovative solutions to advance equity. 7 As editor-in-chief, I will build on the commitment of my predecessor, Dr. Laupacis, to “make CMAJ the journal to which research that has the potential to change Canada’s health care systems is submitted, and in which it is published,” 8 and add “particularly research that has clear potential to advance equity and reduce oppression in health care.”…”