"We extracted data regarding 1099 patients with laboratory-confirmed Covid-19 from 552 hospitals in 30 provinces, autonomous regions, and municipalities in China through January 29, 2020. The primary composite end point was admission to an intensive care unit (ICU), the use of mechanical ventilation, or death."

The New England Journal of Medicine.

https://www.nejm.org/doi/full/10.1056/NEJMoa2002032