Table 4.
Differences in Patient Panel and Patient Characteristics Between ACO-Participating Physician Groups and Nonparticipating Physician Groups by Initial Year of Participationa
| Characteristics | Physician-Group Level | Patient Level | ||
|---|---|---|---|---|
| Percentage Point Difference in Patient Characteristic With ACO Participation (95% CI) | P Value | Percentage Point Difference in Patient Characteristic With ACO Participation (95% CI) | P Value | |
| 2012 Cohort | ||||
| Black | −0.2 (−4.9 to 4.5) | .94 | −1.2 (−6.6 to 4.1) | .65 |
| Dually enrolled | 4.0 (−1.0 to 8.9) | .12 | 3.6 (−2.3 to 9.5) | .23 |
| Living in high-poverty zip code | 15.1 (−7.1 to 37.3) | .18 | 11.3 (−14.9 to 37.4) | .40 |
| High risk | 2.0 (0.3 to 3.7) | .02 | 3.5 (0.8 to 6.2) | .01 |
| No. | 63 714 | NA | 4 801 631 | NA |
| 2013 Cohort | ||||
| Black | 0.8 (−2.7 to 4.3) | .65 | 1.4 (−5.2 to 8.0) | .67 |
| Dually enrolled | 1.6 (−0.5 to 3.6) | .13 | 1.1 (−2.9 to 5.1) | .58 |
| Living in poverty | −7.4 (−19.3 to 4.5) | .22 | −18.3 (−45.5 to 8.9) | .19 |
| High risk | 1.5 (0.4 to 2.5) | .006 | −0.1 (−2.5 to 2.4) | .94 |
| No. | 62 931 | NA | 4 746 511 | NA |
| 2014 Cohort | ||||
| Black | 0.2 (−1.4 to 1.7) | .85 | −0.5 (−4.0 to 3.1) | .80 |
| Dually enrolled | 0.5 (−0.8 to 1.7) | .48 | 0.9 (−2.3 to 4.0) | .59 |
| Living in poverty | −0.3 (−8.2 to 7.6) | .94 | −4.5 (−30.1 to 21.1) | .73 |
| High risk | 1.0 (0.1 to 1.9) | .03 | 1.7 (−0.6 to 4.0) | .15 |
| No. | 62 598 | NA | 4 694 541 | NA |
Abbreviations: ACO, accountable care organization; NA, not applicable.
a
All regressions adjust for the number of physicians in the physician group, the percentage of physicians who were specialists, the percentage of physicians affiliated with a health system, and the percentage of physicians who were hospital based and included hospital service area fixed effects.