Continuous variables are expressed as median values (interquartile ranges), and categorical variables are presented as number of patients (percentages).

Abbreviations: WBC, white blood cell; hs-CRP, high-sensitive C-reactive protein; ART, antiviral treatment; AST, aspartate aminotransferase; COPD, chronic obstructive pulmonary disease; CRRT, continuous renal replacement therapy; ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; APACHE II, Acute Physiology and Chronic Health Evaluation II; SOFA, sequential organ failure assessment; IL-6, interleukin-6.

^a Includes congestive heart disease and coronary atherosclerotic heart disease.

^b Defined as receipt of chemotherapy or radiotherapy within 1 month before the onset of illness or receipt of corticosteroid therapy (equivalent of 30 mg of prednisone per day) for 15 continuous days before the onset of illness.

^c Data are based on real-time reverse transcription–polymerase chain reaction analysis.