Table 3–

Models for Length of Stay

	IRR	95% CI	P-value
Univariable Model
RVD	1.50	1.2–1.8	<0.001
Multiple surgeries	1.96	1.7–2.2	< 0.001
Post-infection	1.28	1.1–1.5	0.001
LVEF	1.00	1.0–1.0	0.427
EF<45%	1.02	0.9–1.2	0.846
EF<35%	1.19	1.0–1.5	0.095
CHF	0.91	0.8–1.0	0.137
CAD	1.09	1.0–1.2	0.146
CVA	1.01	0.9–1.2	0.892
Pulmonary HTN	1.16	1.0–1.4	0.074
RVSP	1.01	1.0–1.0	< 0.001
Multivariable Model 1
RVD	1.57	1.2–2.0	<0.001
LVEF<35%	0.90	0.7–1.2	0.379
Multivariable Model 2
RVD	1.46	1.2–1.8	<0.001
Pulmonary HTN	1.09	0.9–1.3	0.316
Multivariable Model 3
RVD	1.51	1.2–1.8	<0.001
Postop Infection	1.37	1.2–1.6	<0.001
Multivariable Model 4
RVD	1.57	1.3–1.9	<0.001
Postop Infection	1.16	1.0–1.4	0.103
Postop Need for Multiple Surgeries	1.62	1.4–1.9	<0.001
Pulmonary HTN	0.89	0.7–1.1	0.205
Multivariable Model 5
RVD	3.82	1.8–8.3	0.001
RVSP	1.01	1.0–1.0	< 0.001
RVSPxRVD	0.98	1.0–1.0	0.012
Postop Need for Multiple Surgeries	1.89	1.9–2.5	< 0.001

Abbreviations: RVD, right ventricular dysfunction; LVEF, left ventricular ejection fraction; CHF congestive heart failure; CVA, cerebrovascular accident; Pulmonary HTN, pulmonary hypertension; RVSP, right ventricular systolic pressure; IRR, incident rate ratio; CI, confidence interval.

Poisson’s regression was performed to estimate IRR, 95% CI, and p-value. Only covariate that is individually associated with outcome with a p value < 0.1 was included in the multivariable model. LVEF <35% was removed in model 4 due to non-significant Omnibus test. Pulmonary HTN was removed in model 5 due to multicollinearity. All CI noted to be 1.0–1.0 are results of rounding.