Table 1.
Sample characteristics by endocrine therapy usage
| Characteristics | Optimal use No. (%) | Underuse* No. (%) | P † |
|---|---|---|---|
| Total | 1033 (80.7%) | 247 (19.3%) | — |
| Race | |||
| White | 611 (84.0) | 116 (16.0) | <.001 |
| Black | 422 (76.3) | 131 (23.7) | |
| Age at diagnosis, y | |||
| <45 | 214 (74.0) | 75 (26.0) | .003 |
| 45–54 | 339 (80.3) | 83 (19.7) | |
| 55–64 | 273 (83.2) | 55 (16.8) | |
| >65 | 207 (85.9) | 34 (14.1) | |
| AJCC stage at diagnosis | |||
| Stage I | 512 (80.4) | 125 (19.6) | .35 |
| Stage II | 367 (79.4) | 95 (20.6) | |
| Stage III | 134 (84.3) | 25 (15.7) | |
| Unknown | 20 (90.9) | 2 (9.1) | |
| Insurance status at diagnosis | |||
| Any private | 824 (82.7) | 172 (17.3) | <.001 |
| Medicare | 85 (78.7) | 23 (21.3) | |
| Medicaid | 72 (67.3) | 35 (32.7) | |
| Uninsured | 51 (78.5) | 14 (21.5) | |
| Annual Income | |||
| <$15 000 | 129 (75.0) | 43 (25.0) | .03 |
| $15 000 to <$30 000 | 171 (80.3) | 42 (19.7) | |
| $30 000 to $50 000 | 181 (77.0) | 54 (23.0) | |
| >$50 000 | 509 (84.1) | 96 (15.9) | |
| Did not report | 43 (78.2) | 12 (21.8) | |
| Education | |||
| Did not complete high school | 68 (76.4) | 21 (23.6) | .16 |
| High school/some college | 507 (79.3) | 132 (20.7) | |
| College/professional degree | 458 (83.0) | 94 (17.0) | |
| History of receiving Herceptin | |||
| Yes | 126 (77.3) | 37 (22.7) | .24 |
| No | 907 (81.2) | 210 (18.8) | |
| Medication type | |||
| Tamoxifen | 417 (79.0) | 111 (21.0) | <.001 |
| Aromatase inhibitor | 615 (84.5) | 113 (15.5) | |
| Unknown | 1 (4.2) | 23 (95.8) | |
| Changed ET type | |||
| Changed one or more times | 253 (77.4) | 74 (22.6) | .008 |
| Did not change medications | 779 (83.9) | 150 (16.1) | |
| Previously received chemotherapy | |||
| Yes | 556 (80.4) | 111 (19.6) | .73 |
| No | 447 (81.1) | 136 (18.9) | |
| Previously received radiation therapy | |||
| Yes | 749 (80.8) | 178 (19.2) | .88 |
| No | 284 (80.4) | 69 (19.6) | |
| Surgery Type | |||
| Breast conserving | 523 (81.5) | 119 (18.5) | .49 |
| Mastectomy | 510 (79.9) | 128 (20.1) | |
| How ET decision was made | |||
| Primarily patient decision | 172 (72.9) | 64 (27.1) | <.001 |
| Primarily provider decision | 224 (78.6) | 61 (21.4) | |
| Patient and provider (shared) decision | 555 (85.0) | 98 (15.0) | |
| No discussion: ET was just prescribed | 66 (75.0) | 22 (25.0) | |
| Did not report | 16 (88.9) | 2 (11.1) |
*
Underuse is defined as self-reporting either nonadherence (not taking medication as prescribed) or discontinuation (stopping medication altogether) at 2 years postdiagnosis. AJCC = American Joint Committee on Cancer; ET = endocrine therapy.
†
P values were calculated using a two-sided χ2 test of recommended use vs underuse.