Statistical analysis:
Continuous data was expressed as mean ± standard deviation (SD) while categorical data was represented as proportions. The normality of distribution was assessed using the using Shapiro-Wilk test. Comparison of means of continuous variables was done using Student’s t-test or Mann-Whitney U test as appropriate while Fisher exact test or χ2 test was used for categorical variables. In addition, ANOVA or Kruskal Wallis was used to compare mean values of continuous variables between the three groups based on severity of COVID-19. A two-sided P value of < 0.05 was considered to be statistically significant. SPSS version 24.0 (IBM Corp, Armonk, NY) and GraphPad Prism version 8.0.0 (GraphPad Software, San Diego, CA) software were used for statistical analysis.