Understanding China's COVID-19 Statistics
Coronavirus statistics from China, like any other nations, are subject to changing definitions and reporting procedures. They should not be interpreted based only on their face value. For example, according to China CDC, the procedure to confirm COVID-19 cases was expanded to include "clinically diagnosed" in Hubei, but not in other parts of China. It would allow for increased admission of infected patients at the expense of more false positives on February 12. Hospitals in Wuhan were operating over capacity until that time. It resulted in a spike of more than 13,000 cases in Hubei, which gave the false impression of a major outbreak.
This procedure (and definition) was reversed on February 19, resulting in a noticeable drop in "confirmed" cases. On February 20, prison cases that were previously missing from the reports were integrated into China's real-time epidemic reporting system, which was established in the aftermath of SARS in 2003. It resulted in a bump to the reported cases due to additions from 5 prisons in 3 provinces.
Daily reports by China's National Health Commission (NHC) provide national summaries from 31 provinces and cities since January 21, 2020. It began reporting of Wuhan results on January 11, 2020. Statistics on Hong Kong, Macau and Taiwan are included separately in the daily reports.
On March 4, 2020, China's NHC began reporting of imported coronavirus cases. On April 1, 2020 NHC began separate reporting on asymptomatic cases, including imported cases, which previously had been embeded as part of "Under Observation."
On April 8, 2020, China ended its 76-day lockdown of Wuhan, which started on January 23, 2020. The majority of confirmed cases in China are now reported to be imported.
On April 17, 2020, the Wuhan government revised upwards the numbers of confirmed coronavirus cases and deaths in the city. The total confirmed infections in the city was raised by 325 to 50,333, while there are now 1,290 more deaths totaling 3,869, according to the report. The city government provided four explanations for the discrepancy in data, which include incomplete registration of deaths and delayed reporting by medical institutions.
Special thanks to Dr. Paul Li, former virologist at China's National Academy of Science, for his expert explanations.
Daily Number of Hospitals and Capacity Use in Wuhan
The Wuhan Health Commission ceased to report hospital capacity use data after February 25 when the coronavirus situation became under control. On March 16, all 16 temporary hospitals in Wuhan were closed after treating a total of 13,000 patients.
2020/04/17 China National Health Commission: 湖北省武汉市新冠肺炎疫情数据订正情况
Wuhan Health Commission: 武汉市新冠肺炎疫情防控指挥部关于武汉市新冠肺炎确诊病例数确诊病例死亡数订正情况的通报
2020/04/08 People's Daily: 国务院：为加强对新冠病毒无症状感染者的发现、报告、管理工作，依据《中华人民共和国传染病防治法》、《中华人民共和国国境卫生检疫法》，制定本规范。
2020/04/04 FiveThirtyEight: Coronavirus Case Counts Are Meaningless**Unless you know something about testing. And even then, it gets complicated
2020/03/12 World Economic Forum: 6 lessons from China's Zhejiang Province and Hangzhou on how countries can prevent and rebound from an epidemic like COVID-19
2020/02/24 Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)
2020/02/11 CCDC Weekly: Vital Surveillances: The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19) - China, 2020
Asymptomatic Cases in China
Imported Cases Outside Hubei in China
Projections on Total Deaths in China
Projections on Total Deaths for Hubei, China
Projections on Total Deaths Outside Hubei in China
Method: Total Predicted Total = Total Actual + (Serious Cases 重症 * 0.25 * 0.49)
According to a comprehensive study by China CDC, about 25% of the serious cases are under "Critical" conditions. The mortality rate among "Critical" patients is about 49%; no reported deaths under other conditions.
NOTES: Beginning on 2020/04/20, we ceased to report the projected and actual deaths in China because they have statistically reached a stable point around 4,650.
Beginning on 2020/05/01, China's National Health Commission stopped reporting on separate Hubei statistics. Last report by Hubei showed 68,128 confirmed cases and 4,512 deaths (6.6%).
Beginning on 2020/05/04, we ceased to report the asymptomtic case statistics in China because they appeared to be under control.
Visualization of Some Key Indicators of Coronavirus Cases in China