Table 1. Characteristics of participants (n=29,842).
| Characteristics | No. (%) |
|---|---|
| Age (yr) | |
| 6–7 | 9,671 (32.4) |
| 9–10 | 9,756 (32.7) |
| 12–13 | 5,169 (17.3) |
| 15–16 | 5,246 (17.6) |
| Sex (male) | 15,239 (51.2) |
| Past history of allergic diseases | |
| Allergic rhinitis | 10,589 (36.7) |
| Atopic dermatitis | 7,214 (25.0) |
| Asthma | 1,352 (4.7) |
| Response rate by area | |
| Seoul | 3,626/6,500 (55.8) |
| Gyeonggi* | 6,018/12,620 (47.7) |
| Gangwon | 1,349/2,000 (67.5) |
| Chungcheong† | 5,491/7,660 (71.7) |
| Jeolla‡ | 3,213/6,520 (49.3) |
| Gyeongsang§ | 9,306/13,230 (70.3) |
| Jeju | 839/1,470 (57.1) |
*Gyeonggi includes Gyeonggi-do and Incheon; †Chungcheong includes Chungcheongnam-do, Chungcheongbuk-do, Daejeon, and Sejong; ‡Jeolla includes Jeollanam-do, Jeollabuk-do, and Gwangju; §Gyeongsang includes Gyeongsangnam-do, Gyeongsangbuk-do, Daegu, Busan, and Ulsan.