Background: COVID-19 has become a pandemic, but its reported characteristics and outcomes vary greatly amongst studies.
Objectives: We determined pooled estimates for clinical characteristics and outcomes in COVID-19 patients including subgroups by disease severity (based on WHO Interim Guidance Report or IDSA/ATS criteria) and by country/region.
Methods: We searched Pubmed, Embase, Scopus, Cochrane, Chinese Medical Journal, and preprint databases from January 1, 2020 to April 6, 2020. Studies of laboratory confirmed COVID-19 patients with relevant data were included. Two reviewers independently performed study selection and data extraction.
Results: From 6,007 articles, 212 studies from 11 countries/regions involving 281,461 individuals were analyzed. Overall, mean age was 46.7 years, 51.8% were male, 22.9% had severe disease, and mortality was 5.6%. Underlying immunosuppression, diabetes, and malignancy were most strongly associated with severe COVID-19 (coefficient=53.9, 23.4, 23.4, respectively, all p<0.0007), while older age, male gender, diabetes, and hypertension were also associated with higher mortality (coefficient=0.05 per year, 5.1, 8.2, 6.99, respectively, p=0.006 to 0.0002). Gastrointestinal (nausea, vomiting, abdominal pain) and respiratory symptoms (shortness of breath, chest pain) were associated with severe COVID-19, while pneumonia and end organ failure were associated with mortality.
Conclusion: COVID-19 is associated with a severe disease course in about 23% and mortality in about 6% of infected persons. Individuals with comorbidities and clinical features associated with severity should be monitored closely, and preventive efforts should especially target those with diabetes, malignancy and immunosuppression.