Table 2.

Multivariable logistic regression analysis predicting the occurrence of pneumonia following major cancer surgery, Nationwide Inpatient Sample, 1999–2009.

Variables	OR (95% CI)	P
Age	1.024 (1.019–1.03)	<0.001
Gender
Male	1.0 (ref.)
Female	0.919 (0.89–0.948)	<0.001
Race
Caucasian	1.0 (ref.)
Black	0.996 (0.937–1.059)	0.894
Hispanic	0.911 (0.839–0.988)	0.024
Other	0.994 (0.914–1.081)	0.895
Unknown	1.038 (0.999–1.078)	0.059
CCI
0	1.0 (ref.)
1	2.084 (2.014–2.158)	<0.001
2	2.095 (1.976–2.221)	<0.001
≥3	2.087 (1.985–2.195)	<0.001
Year of surgery	1.024 (1.019–1.03)	<0.001
Insurance status
Private	1.0 (ref.)
Medicaid	2.376 (2.196–2.569)	<0.001
Medicare	1.333 (1.272–1.396)	<0.001
Other	1.412 (1.297–1.538)	<0.001
Median household income by ZIP code
1–24,999	1.0 (ref.)
25,000–34,999	0.909 (0.867–0.953)	<0.001
35,000–44,999	0.873 (0.832–0.916)	<0.001
45,000+	0.811 (0.772–0.851)	<0.001
N/A	0.821 (0.733–0.919)	<0.001
Annual hospital volume
Very low	1.0 (ref.)
Low	0.923 (0.885–0.963)	<0.001
High	0.829 (0.792–0.868)	<0.001
Very high	0.721 (0.685–0.758)	<0.001
Hospital location
Rural	1.0 (ref.)
Urban	1.182 (1.122–1.244)	<0.001
Hospital region
Northeast	1.0 (ref.)
Midwest	0.937 (0.893–0.984)	0.009
South	0.983 (0.941–1.026)	0.427
West	0.839 (0.798–0.883)	<0.001
Hospital teaching status
Nonteaching	1.0 (ref.)
Teaching	0.875 (0.845–0.907)	<0.001

OR: odds ratio, CI: confidence interval, ref.: referent category, and CCI: Charlson comorbidity index.