Estimating the instant case fatality rate of COVID-19 in China

The outbreak of coronavirus disease 2019 (COVID-19) in China has been basically controlled. However, the global epidemic of COVID-19 is worsening. We established a method to estimate the instant case fatality rate (CFR) and cure rate of COVID-19 in China.

A total of 82 735 confirmed cases released officially by the Chinese authorities from December 8, 2019 to April 18, 2020 were collected. The estimated diagnosis dates of deaths and cured cases were calculated based on the median cure time or median death time of individual cases. Following this, the instant CFR was calculated according to the number of deaths and cured cases on the same estimated diagnosis date.

In China, the instant CFR of COVID-19 was 3.8-14.6% from January 1 to January 17; it then declined gradually and stabilized at 5.7% in April. The average CFR in China was 6.1±2.9%, while the CFR was 1.0±0.4% in China except Hubei Province. The cure rate of COVID-19 was 93.9±2.9% in China, and stabilized at 94.3%, while it was 99.0±0.4% in China except Hubei Province.

The instant CFR of COVID-19 in China overall was much higher than that in China except Hubei Province. The CFR of COVID-19 in China was underestimated.