Why estimating population-based case fatality rates during epidemics may be misleading

Lucas Böttcher; Mingtao Xia; Tom Chou

The most accurate estimates of M 1 can be obtained if we keep track of the fate of cohorts that were infected within a small time window in the past. By following only these individuals, one can track how many of them died as a function of time. As more cases arise, one should stratify them according to estimated τ to gather improving statistics for M 1 (∞). These data should also be collated according to the other central factor in COVID-19 mortality: patient age. With the further spread of SARS-CoV-2 in different countries, data on more individual cases of death and recovery can be more easily stratified by age, health condition, and other individual characteristics. Using identical initial infection time distributions ρ(τ 1 ; n, γ) (see Eq. (7)), the long-time limit of M 1 p (t) approaches the individual mortalityM 1 (∞) (see Eq. (6)).