Table 2.

Odds Ratio Estimates for 30-day Mortality and 1-Year Mortality

	30-Day Mortality			1-Year Mortality
Variable	OR	95% CI	P-Value	OR Ratio	95% CI	P-Value
Without Volume-Risk Interaction Effect
IMPACT score	1.15	1.14–1.17	<0.001	1.14	1.13–1.15	<0.001
Center Volume
High	---	Reference	---	---	Reference	---
Medium	1.28	1.10–1.49	0.001	1.22	1.10–1.35	<0.001
Low	2.25	1.80–2.82	<0.001	1.76	1.50–2.09	<0.001
Allograft ischemic time
< 2 hours	---	Reference	---	---	Reference	---
≥ 2 hours to < 4 hours	1.20	0.93–1.54	0.2	1.06	0.90–1.25	0.4
≥ 4 hours to < 6 hours	1.91	1.46–2.49	<0.001	1.58	1.33–1.89	<0.001
> 6 hours	2.54	1.88–3.43	<0.001	1.75	1.42–2.15	<0.001
Donor Age	1.01	1.01–1.02	<0.001	1.01	1.01–1.02	<0.001
With Volume-Risk Interaction Effect
IMPACT score	1.15	1.13–1.16	<0.001	1.13	1.12–1.15	<0.001
Center Volume
High	---	Reference	---	---	Reference	---
Medium	1.29	1.12–1.49	0.001	1.20	1.09–1.33	<0.001
Low	1.86	1.46–2.38	<0.001	1.58	1.30–1.92	<0.001
Center Volume-Risk Interaction Effect	1.03	1.01–1.06	0.04	1.04	1.01–1.07	0.02
Allograft ischemic time
< 2 hours	---	Reference	---	---	Reference	---
≥ 2 hours to < 4 hours	1.20	0.93–1.55	0.2	1.06	0.91–1.25	0.4
≥ 4 hours to < 6 hours	1.92	1.46–2.51	<0.001	1.59	1.33–1.89	<0.001
> 6 hours	2.51	1.86–3.39	<0.001	1.75	1.42–2.15	<0.001
Donor Age	1.01	1.01–1.02	<0.001	1.01	1.01–1.02	<0.001

Abbreviations: IMPACT=Index for Mortality Predication After Cardiac Transplantation; OR=Odds ratio; CI=Confidence Interval