The overall average age of the subjects was greater than 60 years. Clinical outcomes were defined as COVID-19 infection in three studies, severity in severn studies, and mortality in eight studies. To provide a quantitative estimate of the association between ACEI/ARB use and severity or mortality risk in COVID-19 patients, the odds ratios (ORs) (most adjusted, if available) and the corresponding 95 % CIs were extracted from published articles. When the ORs were not given, tabular data were used to calculate the corresponding OR.