Table 4.

Cox proportional hazard regression analysis for prediction of the 30-day mortality

Variable	Hazard ratio (95% CI)	P-value
ΔRDW4-1	0.00 (0.00–0.29)	< 0.05
RDW at day 1	1.21 (1.07–1.37)	< 0.05
PSI score	1.01 (1.00–1.02)	< 0.05
Age	0.99 (0.97–1.02)	0.69
Sex	1.14 (0.60–2.15)	0.69
BUN	1.00 (0.98–1.01)	0.55
Total protein	1.03 (0.69–1.54)	0.89
Albumin	0.48 (0.24–0.96)	< 0.05

CI, confidence interval; RDW, red blood cell distribution width; PSI, pneumonia severity index; BUN, blood urea nitrogen.