Case fatality rate of novel coronavirus disease 2019 in China

Rui Qi; Chao Ye; Xiang-rong Qin; Xue-Jie Yu

The copyright holder for this preprint . https://doi.org/10.1101/2020.02.26.20028076 doi: medRxiv preprint 10 / 20 the daily CFR could converge towards the true CFR though more times needed. If assumed T 127 was equal to the true T value, calculated daily CFRs would keep constant. As Figure 2 128 showed, for T= 11 and 8, comparing with T = 9 and 10, CFRs still had slightly decreasing and 129 increasing trends, respectively. Linear models (blue lines) were generated for analysis of 130 variances and linear trends of theses CFR points in each plot. The slopes of models became 131 flatter and approached towards to 0 when T was from 8 to 9 and 11 to 10. The results 132 indicated the true T should be bigger than 8 and less than 11. When T = 9, the CFRs were 133 almost staying in one line (red dotted line in Figure 2 ) and slightly increased later. When T = 134 10, though the daily CFRs decreased early but quickly they reached a stable stage. So the true 135 T might be between 9 and 10 days. The mean values of data in plot 9 and 10 of Figure 2 were 136 0.8% and 0.9%, respectively. The true CFR of COVID-19 in China except Hubei Province 137 should fall between 0.8% and 0.9%. An assumed T was the closer to the true T value, the 138 earlier daily CFRs converging to the true CFR happened. The mean value of CFRs at later 139 stage of plot 9 or 10 was approximately 0.85%. As shown in Figure 2 , if data was analyzed 140 before Feb 20, T = 9 (0.81%) might be determined as the true T value (true CFR). But now 141 the T was postponed to between 9 and 10 days. The reason was not the uncertainty of method, 142 but the long disease course of COVID 19. Time of case confirmation to outcome was longer 143 in some cases than most which caused the true T bigger and CFR slightly increased. For (only sporadic cases were reported recently in the non-Hubei regions), so far, the naive CFR 148 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.