Table 1.
Baseline characteristics of incident thyroid cancer patients and matched controls.
| Characteristic | Thyroid Cancer Cases 1
(n = 418) |
Matched Controls 1
(n = 1648) |
p-Value |
|---|---|---|---|
| Age at cohort enrollment | |||
| Mean (standard deviation) | 51.0 (±6.7) | 51.0 (±6.7) | 1.000 |
| 40–49 | 183 (44.4) | 732 (44.4) | 1.000 |
| 50–59 | 175 (42.5) | 700 (42.5) | |
| ≥60 | 54 (13.1) | 216 (13.1) | |
| Alcohol drinking | |||
| Never | 272 (66.0) | 1077 (65.4) | 0.3970 |
| Former or current | 135 (32.8) | 561 (34.0) | |
| Unknown | 5 (1.2) | 10 (0.6) | |
| Smoking | |||
| Never | 397 (96.4) | 1596 (96.8) | 0.1358 |
| Former or current | 9 (2.2) | 43 (2.6) | |
| Unknown | 6 (1.4) | 9 (0.6) | |
| Sweating exercise once or more per week | |||
| No | 170 (41.3) | 750 (45.5) | 0.2110 |
| Yes | 242 (58.7) | 896 (54.4) | |
| Unknown | 0 (0.0) | 2 (0.1) | |
| Past medical history of hypertension | |||
| No | 348 (84.5) | 1420 (86.2) | 0.2616 |
| Yes | 63 (15.3) | 227 (13.7) | |
| Unknown | 1 (0.2) | 1 (0.1) | |
| Past medical history of diabetes | |||
| No | 394 (95.6) | 1586 (96.3) | 0.6626 |
| Yes | 18 (4.4) | 60 (3.6) | |
| Unknown | 0 (0.0) | 2 (0.1) | |
| Past medical history of hyperlipidemia | |||
| No | 379 (92.0) | 1508 (91.5) | 0.7507 |
| Yes | 33 (8.0) | 140 (8.5) | |
| Past medical history of osteoporosis | |||
| No | 375 (91.0) | 1553 (94.2) | 0.0171 |
| Yes | 37 (9.0) | 95 (5.8) | |
| Past medical history of polyp of intestine | |||
| No | 392 (95.2) | 1608 (97.6) | 0.0088 |
| Yes | 20 (4.8) | 40 (2.4) | |
| Hysterectomy | |||
| No | 346 (84.0) | 1474 (89.4) | 0.0083 |
| Yes | 64 (15.5) | 168 (10.2) | |
| Unknown | 2 (0.5) | 6 (0.4) | |
| Use oral contraceptive | |||
| Never | 324 (78.6) | 1340 (81.3) | 0.2267 |
| Former or current | 82 (19.9) | 296 (18.0) | |
| Unknown | 6 (1.5) | 12 (0.7) | |
| Family history of cancer | |||
| No | 267 (64.8) | 1150 (69.8) | 0.1208 |
| Yes | 143 (34.7) | 487 (29.6) | |
| Unknown | 2 (0.5) | 11 (0.6) | |
| Family history of hypertension | |||
| No | 266 (64.6) | 1105 (67.1) | 0.5224 |
| Yes | 145 (35.2) | 536 (32.5) | |
| Unknown | 1 (0.2) | 7 (0.4) | |
| Family history of diabetes | |||
| No | 313 (76.0) | 1312 (79.6) | 0.1560 |
| Yes | 97 (23.5) | 322 (19.5) | |
| Unknown | 2 (0.5) | 14 (0.9) | |
| Fasting blood sugar | |||
| Mean (standard deviation) | 94.0 (±20.6) | 91.0 (±16.5) | 0.0039 |
| <100 mg/dl | 327 (79.4) | 1370 (83.1) | 0.0861 |
| ≥100 mg/dl | 74 (18.0) | 226 (13.7) | |
| Unknown | 11 (2.6) | 52 (3.2) | |
| Subjective health evaluation | |||
| Good | 127 (30.8) | 578 (35.1) | 0.0463 |
| Normal | 192 (46.6) | 788 (47.8) | |
| Bad | 91 (22.1) | 271 (16.4) | |
| Unknown | 2 (0.5) | 11 (0.7) |
1 Thyroid cancer cases and controls were matched by sex (exactly matched), year of birth (exactly matched), and enrollment year (±1 year). The follow-up duration of the matched controls was set to be the same or longer than that of each thyroid cancer case.