Distribution of Key Variables by Year of Enrollment
| Variable | First Year No. (SD) | Second Year No. (SD) | Third Year No. (SD) | Fourth Year No. (SD) |
|---|---|---|---|---|
| Note: Each patient appears only once in the table, randomly selected from the years they were enrolled. | ||||
| Number of patients | 31,994 | 127,976 | 94,854 | 80,723 |
| Age, years | 40.8 (10.9) | 43.1 (10.9) | 44.7 (10.6) | 45.8 (10.0) |
| Female, % | 53.5 | 52.5 | 51.5 | 51.0 |
| ZIP, socioeconomic status | 0.03 (1.00) | 0.03 (0.98) | 0.05 (0.98) | 0.07 (0.98) |
| ZIP, >12 years school, % | 63.9 (7.80) | 64.3 (7.61) | 64.5 (7.6) | 64.6 (7.6) |
| ZIP, median household income, $ | 37,002 (10,228) | 37,728 (10,176) | 37,905 (10,189) | 38,194 (10,317) |
| ZIP, white, % | 93.9 (12.0) | 94.4 (11.2) | 94.5 (10.9) | 94.7 (10.7) |
| ZIP, white-collar work, % | 74.2 (8.53) | 74.4 (8.6) | 74.6 (8.6) | 74.8 (8.7) |
| Total years enrolled | 1.27 (0.56) | 2.73 (0.82) | 3.49 (0.50) | 4.0 (0) |
| Total ambulatory diagnostic groups | 3.5 (2.68) | 3.3 (2.75) | 3.5 (2.82) | 3.7 (2.90) |
| Any visit, % | 90.1 | 86.2 | 87.0 | 88.5 |
| Any primary care provider visit | 55.6 | 49.2 | 50.0 | 49.6 |
| Mammogram | 51.0 | 52.3 | 56.8 | 58.8 |
| Papanicolaou test | 59.5 | 61.1 | 60.1 | 60.5 |
| Avoidable hospitalization, % | 0.18 | O.15 | 0.12 | 0.15 |
| Expenditures (including nonusers), $ | Mean/Median | Mean/Median | Mean/Median | Mean/Median |
| Total | 1,086/313 | 1,035/285 | 1,112/317 | 1,250/359 |
| Diagnostic | 224/41 | 230/43 | 245/46 | 221/11 |
| Ambulatory | 281/134 | 282/127 | 297/137 | 332/160 |
| Inpatient | 280/0 | 258/0 | 259/0 | 307/0 |
| Expenditures (contingent on use), $ | ||||
| Total | 1,223/383 | 1,227/387 | 1,306/428 | 1,440/467 |
| Diagnostic | 354/137 | 369/165 | 392/165 | 399/131 |
| Ambulatory | 347/183 | 366/189 | 379/203 | 409/217 |
| Inpatient | 5,751/3,005 | 5,617/2,950 | 5,698/2,902 | 6,244/3,019 |