Table 2. Baseline Characteristics of Physician Groups Participating in an ACO by 2014 Compared With Physician Groups Not Participating in an ACOa.
| Characteristic | Physician Group | |
|---|---|---|
| In an ACO (n = 7215) | Not in an ACO (n = 60 676) | |
| Characteristics of physician groups' patient panels | ||
| Black | 12.1 (19.2) | 10.6 (18.1) |
| Dually enrolled in Medicare and Medicaid | 20.8 (23.0) | 17.7 (19.3) |
| Living in high-poverty zip code | 10.7 (5.4) | 11.1 (5.1) |
| High riskb | 34.2 (14.7) | 30.2 (16.2) |
| Characteristics of physician groups | ||
| Specialists in group | 23.3 (0.4) | 37.7 (0.5) |
| Physicians with health system affiliation in group | 4.2 (0.2) | 3.6 (0.2) |
| Physicians with hospital affiliation in group | 4.5 (0.2) | 4.9 (0.2) |
| Physicians in group, No. (%) | ||
| 1-2 | 5218 (72.3) | 46 652 (76.9) |
| 3-9 | 1339 (18.6) | 10 789 (17.8) |
| 10-24 | 348 (4.8) | 2136 (3.5) |
| 25-49 | 146 (2.0) | 624 (1.0) |
| 50-99 | 97 (1.3) | 268 (0.4) |
| ≥100 | 67 (0.9) | 207 (0.3) |
Abbreviation: ACO, accountable care organization.
a
Data are presented as mean (SD) percentage of patients panels’ unless otherwise indicated. Patient characteristics were measured in 2010 to 2011, before ACO participation began.
b
Charlson Comorbidity Index of 3 or more (final risk scores range between 0 and 41, with higher values associated with higher mortality risk over 10 years).