Table 1.
Annual July Total Enrollment in Medicare Advantage Total and by County Medicare Population Quartiles, 1999–2008
| Mean | Total | I | II | III | IV | |
|---|---|---|---|---|---|---|
| Base payment | $655.76 ($94.12) | 2.85*** (0.64) | −0.10*** (0.03) | −0.19*** (0.071) | −0.40** (0.20) | 9.47*** (2.38) |
| HCC | 0.37 (0.40) | 998.48*** (76.75) | 60.07*** (4.53) | 186.72*** (11.50) | 499.95*** (26.87) | 3,469.19***(298.94) |
| Part D and lock-in | 0.30 (0.46) | 442.26*** (28.87) | 34.60*** (2.10) | 98.07*** (4.85) | 219.04*** (10.90) | 1,453.76***(111.04) |
| Medicare pop | 10,340 (27,618) | 0.40*** (0.12) | 0.07*** (0.01) | 0.10*** (0.02) | 0.15*** (0.03) | 0.38***(0.12) |
| Time trend | 5.5 (2.9) | −217.60*** (23.81) | −0.64 (0.82) | −6.37*** (2.43) | −24.74*** (6.04) | −804.96***(85.21) |
| Constant | −3,327.96*** (1,399.95) | 10.59 (19.72) | −64.59 (75.81) | −248.99 (175.45) | −9,061.85*(4,870.70) | |
| County-fixed effects | Yes | Yes | Yes | Yes | Yes | |
| Adj. R2 | 0.983 | 0.650 | 0.764 | 0.838 | 0.981 | |
| N | 30,390 | 30,390 | 7,556 | 7,799 | 7,779 | 7,256 |
Mean of annual enrollment = 1,950.0 (10,034.8).
*, **, *** indicate statistical significance at the 90, 95, and 99 percent confidence intervals, respectively.
Standard deviations (column 1) and standard errors are in parentheses.