Table 4

Cox multivariable regression analyses of determinants of in-hospital mortality

Variables	HR	95.0% CI	P value
Age (tertiles)
62–74 versus <62 years	2.86	1.23 to 6.64	0.014
≥75 versus <62 years	7.92	3.60 to 17.43	<0.001
Number of comorbidities (tertiles)
2–3 versus 0–1	1.85	1.11 to 3.08	0.018
≥4 versus 0–1	2.09	1.23 to 3.55	0.007
Respiratory rate (breaths/min), for unit increase	1.04	1.02 to 1.07	0.001
PaO₂/FiO₂, for unit increase	0.995	0.992 to 0.997	<0.001
Creatinine (mg/dL), for unit increase	1.34	1.18 to 1.51	<0.001
Platelets (10⁹/L), for unit increase	0.995	0.992 to 0.998	0.001

History of cardiovascular disease, hypertension, diabetes, depression, dementia and cancer were included into ‘comorbidities’. Variables excluded (p>0.10) from both models: No. of drugs, Barthel Index, C reactive protein.