Case fatality
The observed case fatality ratios in the described case series from Hubei (including the city of Wuhan) ranged from 4% to 12%. Most case series outside Hubei did not report fatalities. One case series had 1% case fatality. However, more than two thirds of the cases reported from outside Hubei were still hospitalised at the reporting dates. The case fatality ratio among SPP was 6%, which is within the range of the reported COVID-19 case fatalities (Figure 3).
Figure 3  Reported proportions of deceased and corresponding proportions of patients that were still hospitalised, seven COVID-19 case series, China, January–February 2020 (n = 1,087)
COVID-19: coronavirus disease; SARS-CoV: severe acute respiratory syndrome coronavirus.
Grey line: proportion of deceased in pneumonia sentinel patients. Data from five COVID-19 series [5,6,8-12]. A study by Yang et al. described clinical courses and outcomes of 52 critically ill patients in a hospital in Wuhan [14]. Among 25 critically ill COVID-19 patients younger than 60 years, 12 died within 28 days after admission to the ICU. Of 31 patients without chronic illnesses, 15 died, which is a comparable proportion of almost half.
In the sentinel hospitals, we identified 462 pneumonia patients who were critically ill (i.e. received intensive care and ventilation). Of those patients, 92 were younger than 60 years, of whom 12 (13%) died. In addition, 18 of the critically ill pneumonia patients were without chronic preconditions and four of them died.