Table 3. Effects of age and BUN on mortality in multiple Cox regression model with stepwise selection method.

Dependent variable (mortality)	HR	95% CI	SE	P value
Age	1.557	1.141 to 2.216	0.159	0.005
BUN	1.112	1.014 to 1.220	0.047	0.024
BMI	0.867	0.671 to 1.120	0.130	0.274

HR, hazard ratio; SE, standard error; CI, confidence interval; BUN, blood urea nitrogen.