Exhibit 1.

Characteristics of 399 accountable care organizations (ACOs) 2012–15, by commercial contract status

	Noncomme rcial ACOs	Commer cial ACOs	p value
Contract arrangements
Current Medicare ACO contract	91%	62%	<0.001
Current Medicaid ACO contract	17	29	0.02
Two or more private contracts	—a	30	—a
Leadership
Physician led	60%	47%	<0.001
Hospital led	7	5	—b
Jointly led by physicians and one or more hospitals	19	41	—b
Other	14	7	—b
Hospital involvement
ACO includes at least one hospital	47%	71%	<0.001
Previous experience with payment reform activities
Risk-based contractc	28%	50%	<0.001
Bundled or episode-based payments	22	31	<0.01
Pay-for-performance programs	74	84	0.03
Other risk-bearing contract	37	50	<0.001
Physicians employed by the ACO (mean %)
Primary care physicians	20	42	<0.001
Specialists	14	38	<0.001
Types of providers available within the ACOd
Primary care	95%	97%	0.54
Routine specialty care	53	73	<0.001
Pediatric health	39	66	<0.001
Emergency care	39	68	<0.001
Behavioral health	33	48	<0.01
Mean health professionals per 1,000 Medicare beneficiaries in year 1e
Primary care physicians	7.8	9.4	0.05
Specialists	12.8	17.8	0.04
Nurse practitioners	2.7	3.6	0.02
Mean Medicare financial outcomes in year 1f
Attributed beneficiaries	14,347	19,061	0.01
Expenditure benchmark per beneficiary	$12,091	$10,392	<0.001
Savings per beneficiary	$88	$25	0.50
Mean Medicare quality scores in year 1f
Overall quality	70%	74%	<0.001
Patient experience	87	89	0.03
Preventive health	71	71	0.93
Care coordination	65	72	<0.001
At-risk chronic disease measures	58	64	<0.001

SOURCE Authors’ analysis of data for 2012–15 from the National Survey of Accountable Care Organizations and from the Centers for Medicare and Medicaid Services. NOTES Survey data were available for 171 noncommercial and 228 commercial ACOs except where indicated. Year 1 refers to Medicare performance data for the first year of participation in the ACO program [please provide].

^aBy definition noncommercial ACOs do not hold any private contracts[Please provide].

^bStatistical significance was based on the chi-square test for the overall question on leadership

^cData were available for 123 noncommercial and 183 commercial ACOs (question not asked in the original survey).

^dData were available for 160 noncommercial and 215 commercial ACOs (24 missing responses).

^eMedicare data were available for 121 noncommercial and 100 commercial ACOs.

^fMedicare data were available for 135 noncommercial and 113 commercial ACOs.