Table 2.

Overall and procedure-specific risk-adjusted rates of readmission stratified by hospital ACO status and time period. The difference-in-differences represents the added effect of hospital ACO affiliation.

	ACO Hospitals			Non-ACO Hospitals			Difference-in- Differences % (95% CI)
	Pre % (95% CI)	Post % (95% CI)	p- value	Pre % (95% CI)	Post % (95% CI)	p- value
Overall Cohort	8.4 (8.1–8.7)	7.0 (6.7–7.3)	<0.001	7.9 (7.8–8.0)	7.1 (6.9–7.2)	<0.001	−0.52 (−0.97 to −0.08)
Abdominal Aortic Aneurysm Repair	13.5 (12.0–14.9)	10.3 (8.7–11.8)	0.001	12.7 (12.0–13.4)	10.3 (9.5–11.1)	<0.001	−0.84 (−3.1 to 1.4)
Colectomy	15.9 (15.0–16.8)	13.8 (12.6–15.0)	0.004	15.2 (14.8–15.6)	14.3 (13.8–14.8)	0.004	−1.1 (−2.6 to 0.04)
Cystectomy	27.5 (22.4–32.6)	27.6 (22.0–33.3)	0.98	26.2 (23.7–28.7)	26.4 (23.3–29.5)	0.92	−0.12 (−7.6 to 7.4)
Prostatectomy	4.5 (3.6–5.5)	5.2 (3.4–7.0)	0.54	5.5 (4.9–6.1)	5.1 (4.3–5.9)	0.42	1.1 (−1.2 to 3.3)
Lung Resection	12.5 (11.3–13.8)	11.1 (9.7–12.6)	0.17	11.7 (11.0–12.3)	11.0 (10.3–11.7)	0.17	−0.75 (−2.3 to 1.4)
Total knee arthroplasty	5.9 (5.5–6.3)	4.4 (4.0–4.7)	<0.001	5.2 (5.0–5.3)	4.6 (4.4–4.7)	<0.001	−0.91 (−1.4 to −0.35)
Total hip arthroplasty	6.3 (5.8–6.8)	5.7 (5.1–6.3)	0.12	6.3 (6.1–6.6)	5.4 (5.2–5.7)	<0.001	0.33 (−0.47 to 1.1)