Table 1. Characteristics of the Study Population.
| Characteristic | Patients who lost a PCP | Patients who did not lose a PCP | Absolute standardized mean difference |
|---|---|---|---|
| No. of PCPs | 5939 | 5939 | NA |
| No. of Medicare beneficiaries | 169 870 | 189 600 | NA |
| No. of observations | 16 579 457 | 16 579 457 | NA |
| PCP characteristics (2 y prior to PCP exit, matched) | |||
| PCP age, mean (SD), y | 56.8 (12.4) | 55.3 (10.4) | 0.13 |
| Caseload per PCP per mo, meana | 12.1 | 12.1 | 0.01 |
| Female PCPs, % | 25.8 | 25.7 | 0.005 |
| PCPs per practice, % | |||
| 1 (Solo) | 45.7 | 45.7 | 0.0 |
| 2 | 10.5 | 10.5 | 0.0 |
| 3 | 6.7 | 6.7 | 0.0 |
| 4-5 | 10.0 | 10.0 | 0.0 |
| ≥6 | 27.1 | 27.1 | 0.0 |
| Medicare-assigned beneficiary characteristics | |||
| Beneficiary demographics | |||
| Beneficiary age, mean (SD), y | 71.4 (6.1) | 72.0 (5.0) | 0.11 |
| Race, % | |||
| White | 84.0 | 82.7 | 0.05 |
| Black | 9.9 | 9.1 | 0.04 |
| Other | 5.9 | 7.9 | 0.12 |
| Female, % | 37.2 | 36.9 | 0.02 |
| Urban residence, % | 80.9 | 86.3 | 0.15 |
| Beneficiary clinical characteristics | |||
| Elixhauser risk score, mean (SD)b | 2.5 (0.9) | 2.6 (0.8) | 0.05 |
| End-stage kidney disease, % | 1.0 | 1.1 | 0.03 |
| Also enrolled in Medicaid, % | 19.7 | 18.2 | 0.07 |
| Health care use and outcomes 12-24 mo before exit (annual rate per beneficiary) | |||
| Any primary care visit, mean (SD) | 6.0 (3.7) | 6.0 (3.0) | 0.02 |
| Specialty care visits, mean (SD) | 9.6 (5.1) | 9.9 (4.7) | 0.07 |
| Urgent care visits, mean (SD) per 1000 beneficiaries | 9.3 (47.1) | 8.6 (41.7) | 0.02 |
| Emergency department visits, mean (SD) per 100 beneficiaries | 68.9 (65.2) | 61.4 (48.5) | 0.13 |
| Inpatient visits, mean (SD) per 100 beneficiaries | 33.5 (30.5) | 32.8 (26.8) | 0.02 |
| Spending, mean (SD), $ | 7712 (5505) | 7985 (5489) | 0.05 |
| Probability of death, % | 3.6 (1.5) | 3.5 (1.4) | 0.01 |
Abbreviations: PCP, primary care physician; NA, not applicable.
a
The caseload per PCP per month captured the number of unique Medicare beneficiaries seen by each PCP for any type of visit, regardless of whether the PCP was assigned as the beneficiary’s PCP.
b
The Elixhauser Risk Index scores patients based on comorbidities and preexisting conditions that are associated with death; scores range from 0 to 12, with higher scores indicating more coexisting conditions and that beneficiaries are of “higher risk.”