Table.
Study Population Characteristics
| Characteristic | Year 1: 2009 (N = 359) | Year 2: 2010 (N = 395) | Year 3: 2011 (N = 365) | Year 4: 2012 (N = 423) |
|---|---|---|---|---|
| Age at first claim, mean (SD) | 71 (7.7) | 71 (6.6) | 70 (6.9) | 71 (6.9) |
| Female, % | 43.7 | 42.5 | 37.3 | 45.4 |
| Caucasian, % | 77.2 | 83.8 | 81.9 | 83.7 |
| Dual-eligible for Medicare + Medicaid, % | 0.6 | 1.3 | 1.9 | 1.7 |
| Low-income subsidy, % | 17.0 | 18.7 | 17.5 | 18.0 |
| Geographic region | ||||
| Northeast, % | 1.9 | 1.0 | 1.1 | 1.7 |
| Midwest, % | 24.2 | 22.3 | 20.5 | 23.4 |
| South, % | 62.7 | 68.9 | 69.9 | 65.7 |
| West, % | 11.1 | 7.8 | 8.5 | 9.2 |
| Primary treatment | ||||
| Leucovorin only, N (%) | 326 (90.8) | 364 (92.2) | 279 (76.4) | 294 (69.5) |
| Levoleucovorin only, N (%) | 6 (1.7) | 3 (0.8) | 27 (7.4) | 76 (18.0) |
| Mixed treatment, N (%) | 27 (7.5) | 28 (7.1) | 59 (16.2) | 53 (12.5) |
SD indicates standard deviation.