21,392 COVID-19 patients constituted one of the largest cohort studies to date

As of February 27, 2020, 70,233 COVID-19 cases were reported in Hubei Province, including confirmed, clinical, suspected, and asymptomatic cases, some of which were excluded from diagnosis during follow-up. Among them, 21,392 cases were selected for our interview and included in this study. Table S3 shows the comparison of the general demographic characteristics of the included and excluded cases; the two groups had a similar fatality rate (4.77% versus 5.00%, p = 0.21). However, the included participants were more likely to be males and be of a young age. There was no loss to follow-up during the follow-up period, and 1,020 patients died of COVID-19, giving an overall CFR of 4.77% in Hubei. The CFR across different characteristics is presented in Table 1. Patients aged 60 years and older presented the highest fatality rate (14.05%) compared with other groups. A relatively higher fatality rate was observed among males (5.87%) than females (3.58%). Patients with comorbidities had a higher fatality rate (11.33%) than those without (2.98%). An increasing fatality rate was found with higher disease severity, with the highest in the critical level (48.59%).

The patients with a longer interval between symptom onset and diagnosis had a higher fatality rate (7.87% for those longer than 14 days and 4.27% for those fewer than 7 days). Patients admitted to hospital before February 8 had a higher fatality rate (5.97%) than those admitted after February 8, 2020 (2.41%). Relatively higher fatality rates were also present among patients with higher WBC counts (16.50%), a lower count (8.86%) and percentage (8.59%) of lymphocytes, and a higher percentage of neutrophils (7.93%). Differential CFRs were also found across different strata of other factors, such as level of admitted hospital, occupation, and residence.