Table 2.

Characteristics of Patients Treated in IDS-Affiliated Hospital Compared With Non–IDS-Affiliated Hospitals, According to Surgical Procedure

Characteristic	IDS-Affiliated Hospitals	Non–IDS-Affiliated Hospitals	P Value
CABG
Patient, No.	62 414	54 632
Age, mean, y	74.8	74.6	<.001
Female, %	33.0	32.9	.77
Black, %	5.7	5.1	<.001
Admission acuity, % elective	45.1	51.0	<.001
≥2 Elixhauser comorbidities, %	64.0	64.5	.11
Preoperative length of stay, mean, d	3.2	3.3	<.001
Mean Medicare expenditures in 6 months before surgery, $	6500	6720	<.001
Hip replacement
Patient, No.	55 867	58 994
Age, mean, y	76.2	76.1	.36
Female, %	63.2	63.5	.23
Black, %	4.1	3.8	.04
Admission acuity, % elective	92.6	94.5	<.001
≥2 Elixhauser comorbidities, %	53.6	52.2	<.001
Preoperative length of stay, mean, d	1.1	1.1	.45
Mean Medicare expenditures in 6 months before surgery, $	5747	5908	<.001
Back surgery
Patients, No.	49 934	43 943
Age, mean, y	74.2	74.2	.91
Female, %	58.3	57.7	.04
Black, %	5.2	4.9	.07
Admission acuity, % elective	82.8	85.4	<.001
≥2 Elixhauser comorbidities, %	53.7	51 6	<.001
Preoperative length of stay, mean, d	1.6	1.6	.47
Mean Medicare expenditures in 6 months before surgery, $	8829	8847	.76
Colectomy
Patients, No.	19 589	19 815
Age, mean, y	78.4	78.3	.13
Female, %	56.3	55.4	.05
Black, %	8.2	8.5	.21
Admission acuity, % elective	62.9	60.9	<.001
≥2 Elixhauser comorbidities, %	73.0	73.2	.65
Preoperative length of stay, mean, d	2.8	3.0	<.001
Mean Medicare expenditures in 6 months before surgery, $	6416	6486	.45

Abbreviations: CABG, coronary artery bypass grafting; IDS, integrated delivery system.