Characteristics of the whole study population and the study sample
| Whole population | Sample included for analysis | |
| Subjects | 2858 | 2036 |
| Sex | ||
| Male | 1409 (49) | 995 (49) |
| Female | 1449 (51) | 1041 (51) |
| Age of the child, years | 12.6 (6.0–17.2) | 12.2 (6.3–17.0) |
| Age groups | ||
| 6–11 years | 1268 (44) | 975 (48) |
| 12–17 years | 1590 (56) | 1061 (52) |
| Height, cm | 156 (105–195) | 154 (105–194) |
| Height-for-age z-scores# | 0.56±1.01 | 0.56±0.98 |
| BMI z-scores# | 0.06±1.14 | 0.04±1.10 |
| BMI groups | ||
| Underweight (z-scores <−2) | 99 (3) | 61 (3) |
| Normal weight (z-scores >−2– <1) | 2168 (76) | 1573 (77) |
| Overweight (z-scores >1– <2) | 449 (16) | 310 (15) |
| Obesity (z-scores >2) | 142 (5) | 92 (5) |
| Child born in Switzerland¶ | 2522 (88) | 1815 (90) |
| Mother originally from Switzerland¶ | 1833 (64) | 1338 (67) |
| Father originally from Switzerland¶ | 1876 (66) | 1362 (68) |
| Swiss SEP | 70.2 (28.0–98.5) | 70.4 (28.0–98.5) |
| Parent history of asthma¶ | ||
| No | 2404 (84) | 1772 (87) |
| Mother | 236 (8) | 130 (6) |
| Father | 164 (6) | 102 (5) |
| Both | 18 (1) | 9 (<1) |
| Wheeze, past 12 months¶ | 230 (8) | |
| Use of inhaled corticosteroids, past 12 months¶ | 146 (5) | |
| Physician-diagnosed asthma ever¶ | 254 (9) |
Data are presented as n, n (%), median (range) or mean±sd. BMI: body mass index; SEP: socioeconomic position index. #: based on World Health Organization reference; ¶: information obtained from the parent questionnaires.