Regional Variability in COVID-19 Case Fatality Rate in Canada, February-December 2020

Abstract

A total of 475,214 COVID-19 cases, including 13,659 deaths, had been recorded in Canada as of 15 December 2020. The daily reports of confirmed cases and deaths in Canada prior to 15 December 2020 were obtained from publicly available sources and used to examine regional variations in case fatality rate (CFR). Based on a factor of underestimation and the duration of time from symptom onset to death, the time-delay adjusted CFR for COVID-19 was estimated in the four most affected provinces (Quebec, Ontario, Alberta, and British Columbia) and nationwide. The model-based adjusted CFR was higher than the crude CFR throughout the pandemic, primarily owing to the incorporation in our estimation of the delay between case reports and deaths. The adjusted CFR in Canada was estimated to be 3.36% nationwide. At the provincial level, the adjusted CFR was the highest in Quebec (5.13%)-where the proportion of deaths among older individuals was also the highest among the four provinces-followed by Ontario (3.17%), British Columbia (1.97%), and Alberta (1.13%). Provincial-level variations in CFR were considerable, suggesting that public health interventions focused on densely populated areas and elderly individuals can ameliorate the mortality burden of the COVID-19 pandemic.

Keywords: COVID-19; Canada; case fatality rate; mortality; public health.

Figure 1

Temporal distribution of cases (top row) and deaths by area (bottom row), 1 February–15 December 2020. Cumulative cases in (A) Canada (total), (B) Quebec, (C) Ontario, (D) Alberta, and (E) British Columbia (B.C.), and cumulative deaths in (F) Canada (total), (G) Quebec, (H) Ontario, (I) Alberta, and (J) British Columbia (B.C.) are shown.

Figure 2

Crude case fatality rate (CFR; red line) and adjusted CFR estimates (black line) in Canada up to 15 December 2020. The shaded area around the black line illustrates the 95% credible interval (CrI) for the adjusted CFR.

Figure 3

Crude case fatality rate (CFR; red line) and adjusted CFR estimates (black line) in (a) Quebec, (b) Ontario, (c) Alberta, and (d) British Columbia, up to 15 December 2020. The shaded area around the black line illustrates the 95% CrI for the adjusted CFR.