Table 4.

Cox regression analysis of age and treating health region as a predictor for survival. Hazard ratios (HR) and 95% confidence intervals (CI) are shown

Variables in the regression model	Unadjusted HR	95% CI	p value	Adjusted HR	95% CI	p value
Age less than 4 years	2.455	1.446 to 4.167	0.001	2.572	1.512 to 4.373	<0.001
Treated in the high-volume health region	1.900	1.082 to 3.336	0.025	2.012	1.145 to 3.533	0.015