Univariate and Multivariate Analyses of Factors Predicting OS
| Factor | No. of subjects/deaths | Crude RR | P | Adjusted RR | P |
| Sex | |||||
| Male | 129/57 | 1 (ref) | <0.001 | 1 (ref) | <0.001 |
| Female | 221/55 | 0.42 (0.29–0.62) | 0.49 (0.33–0.74) | ||
| Age at the diagnosis of distant metastasis (y) | |||||
| 0–29 | 80/3 | 1 (ref) | 1 (ref) | ||
| 30–39 | 54/11 | 6.43 (1.79–23.10) | 4.54 (1.24–16.61) | ||
| 40–49 | 56/18 | 9.87 (2.91–33.52) | <0.0001 | 7.65 (2.22–26.32) | <0.0001 |
| 50–59 | 70/31 | 21.57 (6.55–71.10) | 11.49 (3.33–39.59) | ||
| 60–69 | 57/31 | 23.60 (7.15–77.95) | 13.18 (3.83–45.31) | ||
| 70–90 | 35/18 | 42.88 (12.39–148.37) | 23.03 (6.24–85.08) | ||
| Extent of metastases | |||||
| Category 1 | 83/8 | 1 (ref) | 1 (ref) | ||
| Category 2 | 109/31 | 3.65 (1.68–7.94) | <0.001 | 2.71 (1.22–6.03) | <0.01 |
| Category 3 | 160/73 | 8.43 (4.04–17.58) | 3.49 (1.56–7.81) | ||
| Site of metastases | |||||
| Lung | 205/51 | 1 (ref) | 1 (ref) | ||
| Bone | 84/32 | 2.17 (1.38–3.39) | <0.001 | 1.33 (0.77–2.31) | 0.24 |
| Lung and bone ± other | 63/29 | 3.58 (2.24–5.72) | 1.63 (0.92–2.91) | ||
| Histology | |||||
| Papillary thyroid carcinoma | 245/72 | 1 (ref) | 1 (ref) | ||
| Follicular thyroid carcinoma | 107/40 | 1.61 (1.09–2.39) | 0.02 | 0.67 (0.42–1.07) | 0.09 |
| Center | |||||
| GR | 231/68 | 1 (ref) | 1 (ref) | ||
| MSKCC | 121/44 | 1.77 (1.20–2.62) | 0.01 | 1.41 (0.87–2.29) | 0.16 |
ref = reference; Category 1 = patients with metastases on 131I WB scan but with normal radiologic imaging; category 2 = patients with micronodular lung metastases defined radiologically < 1 cm or with a single bone metastasis identified radiologically; category 3 = macronodular lung metastases or multiple bone metastases or both bone and lung metastases.
Data in parentheses are 95% CIs.