Table 5.

Negative Binomial Regression Describing the Relationship between Postoperative Infection, Patient Characteristics, Comorbidities, and LOS

	IRR*	95% CI†	SE†	P ‡
Infection	1.55	(1.48–1.63)	0.025	<0.001
Diabetes	1.07	(1.02–1.13)	0.026	0.0054
Age	0.99	(0.99–1.00)	6.91e-04	<0.001
Hypertension	1.05	(1.02–1.10)	0.018	0.0020
Smoking status	0.95	(0.90–1.00)	0.027	0.049
Obesity	0.97	(0.93–1.02)	0.024	0.25
Neoadjuvant chemotherapy	1.44	(1.40–1.50)	0.017	<0.001
Radiation	1.11	(1.06–1.15)	0.020	<0.001

^*IRR denotes incidence rate ratio, which compares the incidence rate of total hospital days LOS between patients with and without characteristics of interest.

^†SE, standard error.

^‡Significance is defined as P < 0.00625, adjusted per the Bonferroni correction for multivariate regression.