Characteristics of all participants from school fourth-, fifth- and sixth-graders in the Taiwan Children Health Study
| 2010 | 2011 | 2012 | |
| Subjects# | 2777 | 2170 | 2311 |
| Males | 1411 (50.8) | 1077 (49.6) | 1162 (50.3) |
| Age years | 9.7±0.5 | 10.6±0.50 | 11.7±0.5 |
| Parental education years | 12.9±2.2 | 12.9±2.2 | 12.9±2.3 |
| Household income per month | |||
| <50 000 TWD | 1145 (41.2) | 926 (42.7) | 940 (40.7) |
| 50 000–100 000 TWD | 1023 (36.8) | 795 (36.6) | 878 (38.0) |
| >100 000 TWD | 509 (18.3) | 373 (17.2) | 418 (18.1) |
| In utero smoke exposure | 86 (3.1) | 70 (3.2) | 70 (3.0) |
| Breastfeeding | 1407 (50.7) | 1092 (50.3) | 1188 (51.4) |
| Family history of atopy | 955 (34.4) | 750 (34.6) | 803 (34.8) |
| Obesity measures | |||
| Body mass index kg·m−2 | 18.6±3.6 | 19.2±3.5 | 20.3±3.9 |
| Body fat (skinfolds) % | 23.2±8.0 | 27.7±8.2 | 25.4±7.4 |
| Waist-to-hip ratio % | 81.5±5.9 | 81.7±5.8 | 77.3±6.7 |
| Respiratory outcomes¶ | |||
| Active asthma | 134 (4.8) | 105 (4.8) | 80 (3.5) |
| Lifetime wheeze | 394 (14.2) | 471 (21.7) | 487 (21.1) |
| Atopy¶ | |||
| AR | 891 (32.1) | 886 (40.8) | 867 (37.5) |
| AD | 331 (11.9) | 318 (14.7) | 374 (16.2) |
| AC | 356 (12.8) | 379 (17.5) | 375 (16.2) |
| AR or AD or AC | 1120 (40.3) | 1049 (48.3) | 1045 (45.2) |
| Pulmonary function | |||
| FEV1/FVC % | 90.7±6.7 | 91.8±6.1 | 91.6±6.5 |
| Airway inflammation | |||
| FeNO ppb | 11.5±17.1 |
Data are presented as n, n (%) or mean±sd. TWD: Taiwan dollars; AR: allergic rhinitis; AD: atopic dermatitis; AC: acute conjunctivitis; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; FeNO: exhaled nitric oxide fraction. #: missing data; ¶: p<0.05 among the three surveys by ANOVA.