Table 5.

Effects on mortality by uni- and multivariate analysis

	Univariate analysis			Continuous-volume model
	OR	95 % CI	p Value	OR	95 % CI	p value
Volume (per 100 cases/year)	0.72	(0.67–0.77)	< 0.0001	0.84	(0.78–0.90)	< 0.0001
Risk category 5&6 vs 1	111.9	(89.8–139.6)	< 0.0001	67.0	(53.1–84.5)	< 0.0001
Risk category 4 vs 1	33.3	(26.9–41.4)	< 0.0001	23.1	(18.5–28.9)	< 0.0001
Risk category 3 vs 1	13.1	(10.6–16.1)	< 0.0001	10.1	(8.2–12.5)	< 0.0001
Risk category 2 vs 1	3.9	(3.1–4.8)	< 0.0001	3.4	(2.7–4.2)	< 0.0001
Neonates vs children	8.5	(7.8–9.3)	< 0.0001	3.3	(3.0–3.6)	< 0.0001
Infants vs children	2.5	(2.3–2.8)	< 0.0001	2.3	(2.1–2.5)	< 0.0001
Neonates vs infants	3.4	(3.1–3.6)	< 0.0001	1.4	(1.33–1.6)	< 0.0001
Time period 1 vs 5	4.4	(3.8–5.0)	< 0.0001	6.5	(5.6–7.6)	< 0.0001
Time period 2 vs 5	3.3	(2.9–3.7)	< 0.0001	4.2	(3.7–4.8)	< 0.0001
Time period 3 vs 5	2.7	(2.4–3.0)	< 0.0001	3.1	(2.7–3.5)	< 0.0001
Time period 4 vs 5	1.8	(1.6–2.0)	< 0.0001	1.9	(1.7–2.1)	< 0.0001
Females vs males	0.98	(0.92–1.04)	0.4993	1.20	(1.13–1.29)	< 0.0001

OR odds ratio, CI confidence interval