Population-Level Death Rates From Novel Coronavirus (COVID-19) in South Korea

Soneji, Samir; Beltrán-Sánchez, Hiram; Yang, JaeWon; Mann, Caroline

South Korea was among the first countries to report a case of the novel coronavirus (COVID-19). As of August 14, 2020, South Korea reported 14 873 confirmed cases and 305 deaths from COVID-19. We collected the number of laboratory-confirmed cases and deaths by age from the Korean Centers for Disease Control and Prevention. We estimated population-level death rates by fitting a logistic regression model using Firth's bias reduction method. We calculated the age-standardized death rate (ASDR) varying the COVID-19 prevalence and level of death undercount. Estimated population-level death rates of COVID-19 (deaths per 100 000 person-years) increased with age: 0.1 among 30 to 39 year olds, 1.1 among 60 to 69 year olds, and 14.5 among ≥80 year olds. The ASDR (deaths per 100 000 person-years) was 0.9 based on the current deaths and population-level prevalence of 0.03%. If the prevalence increased to 0.6% and 30% of COVID-19 deaths had not been reported, the ASDR would further increase to 13.7 to become the seventh leading cause of death. Currently, the population-level mortality burden of COVID-19 in South Korea, as measured by the ASDR, was relatively low compared with other causes but could increase substantially if the prevalence increases from another outbreak or COVID-19 deaths were undercounted.