Table II.

Baseline characteristics of study population, including comparison between surgery and nonsurgery groups

Baseline characteristics	All patients (n = 116,195)	No surgery (n = 73,116)	Surgery (n = 43,079)	P value
Mean age, y (SD)	65.0 (16.5)	65.8 (16.6)	65.6 (16.2)	<.0001
Sex, % female	59.3%	56.8%	63.6%	<.0001
Race
White	73.4%	73.0%	74.0%	<.0001
Black	12.1%	11.4%	13.3%
Hispanic	11.2%	12.1%	9.5%
Other	3.4%	3.5%	3.2%
Insurance type, %
Medicare	58.5%	60.9%	54.5%	<.0001
Medicaid	6.1%	5.9%	6.3%
Private	26.4%	24.4%	29.6%
Other	9.1%	8.8%	9.6%
Income (% in quartile, by zip code)
1 ($0–$38,999)	28.9%	28.6%	29.4%	<.0001
2 ($39,000–$47,999)	31.8%	31.6%	32.2%
3 ($48,000–$63,999)	26.6%	26.9%	26.3%
4 ($64,000+)	12.7%	13.0%	12.2%
Comorbidities
Chronic hypertension	56.9%	56.1%	58.2%	<.0001
Disorder of electrolytes	34.3%	32.4%	37.6%	<.0001
Anemia	18.8%	16.5%	22.7%	<.0001
Chronic lung disease	18.3%	16.5%	21.5%	<.0001
Diabetes mellitus	18.3%	17.9%	19.0%	<.0001
Depression	9.4%	9.3%	9.6%	.1376
Chronic renal failure	7.6%	7.5%	7.8%	.0269
Congestive heart failure	6.7%	5.8%	8.3%	<.0001
Peripheral vascular disease	6.3%	5.7%	7.2%	<.0001
Neurologic disorder	5.9%	6.0%	5.7%	.0133
Malnutrition	5.6%	3.8%	8.5%	<.0001
Valvular disease	5.1%	4.7%	5.7%	<.0001
Disorder of coagulation	3.2%	2.5%	4.4%	<.0001
Liver disease	2.7%	2.7%	2.8%	.2051
Age-adjusted CCI	4.1 (SD = 2.5)	4.2 (SD = 2.5)	3.9 (SD = 2.5)	<.0001
Type of obstruction
Adhesive	66.1%	81.7%	55.6%	<.0001
Ventral/incisional hernia	15.2%	3.9%	40.5%	<.0001
Volvulus	3.5%	1.7%	7.0%	<.0001
Inflammatory bowel disease	2.6%	3.8%	2.1%	<.0001
Malignancy	2.1%	4.7%	1.0%	<.0001
Intussusception	1.0%	1.0%	1.4%	<.0001
Other	9.5%	12.6%	4.2%	<.0001
Underwent operation
Yes	37.1%	—	—
No	62.9%	—	—