Table 1.
Association of Patient, Tumor, and Initial Treatment Characteristics With Treatment-Free Survival
| Characteristic | N (%) | AHR (95% CI) |
|---|---|---|
| Patient characteristic | ||
| Age, y | ||
| Median (range) | 69 (21–98) | 1.00 (0.99–1.00) |
| Sex | ||
| Female | 6938 (74.8) | 1 (Reference) |
| Male | 2335 (25.2) | 1.35 (1.20–1.52) |
| Race | ||
| White | 7613 (82.1) | 1 (Reference) |
| Black | 680 (7.3) | 1.06 (0.85–1.34) |
| Other | 980 (10.6) | 1.07 (0.90–1.27) |
| Percentage with high school education only | ||
| <20% | 2195 (23.7) | 1 (Reference) |
| 20%–29.9% | 3168 (34.2) | 0.95 (0.82–1.10) |
| ≥30% | 3554 (38.3) | 0.92 (0.79–1.08) |
| Unknown | 356 (3.8) | |
| Household income | ||
| <$35,000 | 1627 (17.6) | 1.03 (0.86–1.23) |
| $35,000–$59,000 | 4188 (45.2) | 1.03 (0.90–1.18) |
| ≥$60,000 | 3098 (33.4) | 1 (Reference) |
| Unknown | 360 (3.9) | |
| Tumor characteristic | ||
| Stage | ||
| Localized | 6920 (74.6) | 1 (Reference) |
| Regional | 1902 (20.5) | 2.13 (1.82–2.49) |
| Distant | 451 (4.9) | 4.43 (3.68–5.33) |
| Histology | ||
| Follicular | 763 (8.2) | 1.19 (0.99–1.44) |
| Hürthle cell | 518 (5.6) | 1.36 (1.09–1.69) |
| Papillary | 7992 (86.2) | 1 (Reference) |
| Tumor size | ||
| ≤1 cm | 3580 (38.6) | 1 (Reference) |
| >1 cm and ≤2 cm | 2082 (22.5) | 1.36 (1.14–1.62) |
| >2 cm and ≤4 cm | 1972 (21.3) | 1.69 (1.43–2.01) |
| >4 cm | 1213 (13.1) | 2.11 (1.74–2.55) |
| Unknown | 426 (4.6) | 2.00 (1.56–2.57) |
| Initial treatment characteristic | ||
| Surgery | ||
| Lobectomy | 1922 (20.7) | 0.88 (0.73–1.05) |
| Total thyroidectomy | 7351 (79.3) | 1 (Reference) |
| Lymph node resection | ||
| Not resected | 6047 (65.2) | 1.01 (0.87–1.18) |
| Resected and negative | 2065 (22.3) | 1 (Reference) |
| Resected and positive | 1161 (12.5) | 1.38 (1.14–1.67) |
| Radioactive iodine | ||
| No | 5569 (60.1) | 1 (Reference) |
| Yes | 3704 (39.9) | 1.47 (1.29–1.68) |
| Radiation | ||
| No | 8918 (96.2) | 1 (Reference) |
| Yes | 355 (3.8) | 1.68 (1.33–2.12) |
Abbreviation: AHR, adjusted hazard ratio.