Epidemiology of COVID‐19: A Systematic Review and Meta‐analysis of Clinical Characteristics, Risk factors and Outcomes

Li, Jie; Huang, Daniel Q.; Zou, Biyao; Yang, Hongli; Hui, Wan Zi; Rui, Fajuan; Yee, Natasha Tang Sook; Liu, Chuanli; Nerurkar, Sanjna Nilesh; Kai, Justin Chua Ying; Teng, Margaret Li Peng; Li, Xiaohe; Zeng, Hua; Borghi, John A.; Henry, Linda; Cheung, Ramsey; Nguyen, Mindie H.

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. This article is protected by copyright. All rights reserved.