Estimating instant case fatality rate of COVID-19 in China

Mi, Yan-ni; Huang, Ting-ting; Zhang, Jun-xia; Qin, Qi; Gong, Ya-xin; Liu, Si-yu; Xue, Hui-min; Ning, Chang-hua; Cao, Lei; Cao, Yong-xiao

Abstract Objective 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 instant case fatality rate and cure rate of COVID-19 in China. Methods We collected 82735 confirmed cases released officially by Chinese authorities from Dec 8, 2019 to April 18, 2020. The estimated diagnosis dates of deaths and cured cases were calculated based on median cure time or median death time of individual cases. Afterward, instant fatality rate was calculated according to the number of deaths and cured cases on the same estimated diagnosis date. Results In China, the instant case fatality rate of COVID-19 was 3.8-14.6% from Jan 1 to Jan 17, and then gradually declined and stabilized at 5.7% in April. The average case fatality rate in China was 6.1%±2.9%. While, the case fatality rate was 1.0±0.4% in China except Hubei. The cure rates of COVID-19 were 93.9%±2.9% in China, and stabilized at 94.3%, while it was 99.0%±0.4% in China except Hubei. Conclusion The instant case fatality rate of COVID-19 in China was much higher than that in China except Hubei. The case fatality rate of COVID-19 in China was underestimated.