. 2017 Aug 1;318(5):453–461. doi: 10.1001/jama.2017.9643

Table 1. Patient, Clinician, and Physician Practice Characteristics, 2013.

Characteristic	Physician Practice Category
Characteristic	Low Risk^a	High Medical Risk Only^b	High Social Risk Only^c	High Medical and Social Risk
Practices, No.	547	128	102	122
Clinicians, No.	175 009	47 397	28 975	32 788
Attributed beneficiaries, No.	4 326 076	470 388	166 783	226 633
Physician practices successfully reporting, No. (%)	433 (79.2)	89 (69.5)	48 (47.1)	66 (54.1)
Beneficiaries
Age group, y, %
0-64	18	24	44	38
65-84	70	63	49	48
≥85	12	13	7	13
Female sex, %	57	57	56	57
Race/ethnicity, %^d
Non-Hispanic black	8	16	24	31
Hispanic	3	5	14	8
Dually enrolled in Medicare and Medicaid, %	15	23	53	54
Disabled based on Medicare entitlement, %	21	27	49	45
Clinicians and physician practices
Specialty type, %^e
Primary care^f	28	20	24	25
Medical	19	27	16	22
Surgical	10	10	9	9
Other^g	19	20	27	24
Nonphysician	24	22	24	20
Met stage 1 meaningful use, %^e^,^h	31	29	8	14
Clinicians/practice, mean (range), No.	320 (100-5984)	370 (100-3068)	284 (100-6488)	269 (100-1671)

^{^a}

Neither high medical risk nor high social risk.

^{^b}

Had a mean Hierarchical Condition Category risk score greater than the 75th percentile among all fee-for-service beneficiaries.

^{^c}

In the top quartile of the proportion of attributed beneficiaries who were dually eligible for Medicare and Medicaid (ie, enrolled in Medicaid in January 2013).

^{^d}

Self-reported at the time of application for a social security number and recorded as white non-Hispanic; black non-Hispanic; Asian, Asian American, or Pacific Islander; Hispanic; or North American Indian or Alaskan Native.

^{^e}

The denominator is the number of clinicians.

^{^f}

Includes general practice, pediatrics, geriatric medicine, internal medicine, or family practice.

^{^g}

Includes obstetrics and gynecology, psychiatry, psychology, radiology, emergency medicine, anesthesiology, and ophthalmology.

^{^h}

Clinicians must adopt electronic health records across a number of dimensions as specified by the Centers for Medicare & Medicaid Services; this does not include Medicaid meaningful use.