Estimates of COVID-19 case-fatality risk from individual-level data

Simona Bignami; Daniela Ghio; Ari Van Assche

The severity profile of a novel pathogen is one of the most critical issues as it begins to spread, when assessing disease course and outcome is crucial for planning health interventions (1) . For this reason, an important epidemiological indicator to monitor during the current outbreak of COVID-19 is the case-fatality risk (CFR), the proportion of confirmed cases who result in fatalities. When calculated from aggregate data on confirmed cases and deaths, the CFR is a simple ratio between the former and the latter, which is prone to numerous biases (1) (2) (3) (4) (5) . With individual-level data, the CFR can be estimated as a true measure of risk as the proportion of incidence for the disease. name of the reporting health facility for these cases. Individuals' age is recorded at the time of 1 The dataset for Ontario is available at: https://data.ontario.ca/dataset?keywords_en=COVID-19. The dataset for Alberta at: https://covid19stats.alberta.ca. 2 The number of COVID-19-related deaths recorded in Alberta (48 as of April 15) is too small for this type of analysis.