Table 1. Sample characteristics.
| D12 | D23 | D13 | |||||
| Sex | Men | 121,551 | (50.2%) | 93,758 | (50.2%) | 5,356 | (50.5%) |
| Women | 120,352 | (49.8%) | 93,064 | (49.8%) | 5,243 | (49.5%) | |
| Age, years | 0–4 | 9,696 | (4.0%) | 0 | (0.0%) | 0 | (0.0%) |
| 5–9 | 67,459 | (27.9%) | 42,945 | (23.0%) | 4,504 | (42.5%) | |
| 10–14 | 86,020 | (35.6%) | 75,780 | (40.6%) | 1,670 | (15.8%) | |
| 15–19 | 64,888 | (26.8%) | 59,075 | (31.6%) | 2,542 | (24.0%) | |
| 20–24 | 13,836 | (5.7%) | 8,224 | (4.4%) | 1,607 | (15.2%) | |
| 25–27 | 4 | (0.0%) | 798 | (0.4%) | 276 | (2.6%) | |
| BMI, kg/m2 | 5 to <15 | 31,189 | (12.9%) | 18,304 | (9.8%) | 1,659 | (15.7%) |
| 15 to <20 | 134,620 | (55.7%) | 103,149 | (55.2%) | 5,442 | (51.3%) | |
| 20 to <25 | 63,950 | (26.4%) | 55,013 | (29.4%) | 2,815 | (26.6%) | |
| 25 to <30 | 9,635 | (4.0%) | 8,281 | (4.4%) | 500 | (4.7%) | |
| 30 to <50 | 2,509 | (1.0%) | 2,075 | (1.1%) | 183 | (1.7%) | |
| Interval, years | Minimum | 0.019 | 0.071 | 1.159 | |||
| 1st Quantile | 1.986 | 1.841 | 3.663 | ||||
| Median | 2.088 | 2.005 | 4.049 | ||||
| Mean | 2.126 | 2.031 | 4.025 | ||||
| 3rd Quantile | 2.252 | 2.197 | 4.397 | ||||
| Maximum | 6.562 | 5.608 | 8.211 | ||||
| Number of diagnosed thyroid cancer |
69 | 28 | 2 | ||||
| Total | 241,903 | 186,822 | 10,599 | ||||
Dxy, the subgroup that underwent thyroid screening examination at the xth and yth round surveys.