Tang (2020)
Comparison of Hospitalized Patients With ARDS Caused by COVID-19 and H1N1
Laboratory Findings
PT (1 unit increase vs. Not applicable)
COVID-19 (severe/critical)
Odds ratio: 1.595 (1.165-2.183) Adjusted model


Retrospective case-control study

Medical records


Patients infected with COVID-19 admitted to the Department of Pulmonary and Critical Care at Wuhan Pulmonary Hospital in Hubei Province of China, among which 73 cases included ARDS.

Two independent cohorts of patients with ARDS infected with either COVID-19 or H1N1 were compared. Their clinical manifestations, imaging characteristics, treatments, and prognosis were analyzed and compared. The median age of patients with COVID-19 was 67 years, which was significantly higher than that of patients with H1N1 (52 years; P < .001). The proportion of male subjects in the COVID-19 group was 61.5%, which was significantly lower than that of the H1N1 group (80.0%; P = .011). In terms of underlying diseases, 31.5% of COVID-19 patients has a history of cardiovascular disease, whereas that of H1N1 patients was significantly lower (10.7%; P = .002). There was no significant difference in the history of hypertension, diabetes, or chronic airway diseases between the two groups. Controls: 75 patients were infected with H1N1.


46 Day

COVID-19 (severe/critical)


Patients with ARDS infected with COVID-19

Laboratory Findings


Prothrombin time, s

Not applicable

1 unit increase

Odds ratio

1.595 (1.165-2.183)




Risk adjusted for Age, Cardiovascular disease, SOFA score, APACHE II score, Fatigue, Sputum, GI symptoms, Myalgia, Prothrombin time, AST, Lactate dehydrogenase, Ground-glass opacity, Consolidation

Reported values were used to manually calculate ORs for COVID-19: log(ORswitch)=log(1OR)