Statistical analysis
The continuous variables were summarized as medians and interquartile
ranges and compared by the Mann-Whitney-Wilcoxon test. The categorical
data were summarized using frequencies and percentages and examined by
the chi-square test or the Fisher exact test, as appropriate. The
logistic regression model was used to assess the odds ratio of treatment
with ACEI vs. ARB on the severity of illness and ARDS. The survival
curves of COVID-19 patients were assessed by Kaplan-Meier plots using
the log-rank test. The Cox proportional hazards regression model was
used to determine the hazard ratios of ACEI vs. ARB use on death. All
tests were 2-sided, and P-value >0.05 was considered as
statistically significant. All analyses were conducted by Stata/SE
version 12 (Stata Crop) and GraphPad Prism version 8 (GraphPad Software
Inc).