In this subgroup analysis, the multivariate analysis revealed that age (HR: 2.225; 95% CI: 1.184–4.182; p value: 0.013), D-Dimer (HR: 2.942; 95% CI: 1.126–7.684; p value: 0.028), CRP(HR: 4.356; 95% CI: 1.665–11.398; p value: 0.003), PCT (HR: 8.098; 95% CI: 1.913–34.278; p value: 0.004), were associated with 30-day COVID-19 mortality. This evidence concerns the gene CRP and COVID-19.