Scientific Reports (Jun 2022)

Clinical risk, sociodemographic factors, and SARS-CoV-2 infection over time in Ontario, Canada

  • Jacob A. Udell,
  • Bahar Behrouzi,
  • Atul Sivaswamy,
  • Anna Chu,
  • Laura E. Ferreira-Legere,
  • Jiming Fang,
  • Shaun G. Goodman,
  • Justin A. Ezekowitz,
  • Kevin R. Bainey,
  • Sean van Diepen,
  • Padma Kaul,
  • Finlay A. McAlister,
  • Isaac I. Bogoch,
  • Cynthia A. Jackevicius,
  • Husam Abdel-Qadir,
  • Harindra C. Wijeysundera,
  • Dennis T. Ko,
  • Peter C. Austin,
  • Douglas S. Lee

DOI
https://doi.org/10.1038/s41598-022-13598-z
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 14

Abstract

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Abstract We aimed to determine whether early public health interventions in 2020 mitigated the association of sociodemographic and clinical risk factors with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We conducted a population-based cohort study of all adults in Ontario, Canada who underwent testing for SARS-CoV-2 through December 31, 2020. The outcome was laboratory-confirmed SARS-CoV-2 infection, determined by reverse transcription polymerase chain reaction testing. Adjusted odds ratios (ORs) were determined for sociodemographic and clinical risk factors before and after the first-wave peak of the pandemic to assess for changes in effect sizes. Among 3,167,753 community-dwelling individuals, 142,814 (4.5%) tested positive. The association between age and SARS-CoV-2 infection risk varied over time (P-interaction < 0.0001). Prior to the first-wave peak, SARS-CoV-2 infection increased with age whereas this association reversed thereafter. Risk factors that persisted included male sex, residing in lower income neighborhoods, residing in more racially/ethnically diverse communities, immigration to Canada, hypertension, and diabetes. While there was a reduction in infection rates after mid-April 2020, there was less impact in regions with higher racial/ethnic diversity. Immediately following the initial peak, individuals living in the most racially/ethnically diverse communities with 2, 3, or ≥ 4 risk factors had ORs of 1.89, 3.07, and 4.73-fold higher for SARS-CoV-2 infection compared to lower risk individuals in their community (all P < 0.0001). In the latter half of 2020, this disparity persisted with corresponding ORs of 1.66, 2.48, and 3.70-fold higher, respectively. In the least racially/ethnically diverse communities, there was little/no gradient in infection rates across risk strata. Further efforts are necessary to reduce the risk of SARS-CoV-2 infection among the highest risk individuals residing in the most racially/ethnically diverse communities.