Statistical Analysis
Data descriptive analysis was carried out using Microsoft Excel®, and statistical analysis was performed using SPSS software. We evaluated discrete variables to determine the risk factor for short-term mortality in COVID-19 patients with and without comorbidities. The t-test, Mann-Whitney test, and χ2test statistics were used to determine differences in study variables between groups. We used Cox proportional hazard models to determine whether comorbidities were predictive of in-hospital mortality. A proportional subdistribution hazards model analysis was utilized, in which death is represented as a competing risk. The univariate models’ significant predictors were then included in multivariate models, adjusting for possible confounding variables. The proportional hazard assumption was tested for all reported variables. Odds ratios with 95% confidence intervals were obtained. A two-sided p-value of 0.05 was considered statistically significant.