Population characteristics at the three examinations
| Age at examination | |||
| 8 years | 16 years | 24 years | |
| Number of participants at | |||
| Questionnaire | 628 | 616 | 596 |
| Physical examination | 549 | 551 | 496 |
| Spirometry | 425 | 471 | 431 |
| Females, n (%) | 326 (52) | 329 (53) | 327 (55) |
| Fulfilling criteria for asthma, n (%) | 290 (46) | 399 (66) | 382 (64) |
| Fulfilling criteria for asthma males, n (%) | 172 (57) | 180 (64) | 153 (57) |
| Fulfilling criteria for asthma females, n (%) | 118 (36) | 219 (67) | 229 (70) |
| Environmental tobacco smoke exposure, n (%) | 104 (16) | 81 (14) | 73 (14) |
| Own smoking, n (%) | – | 71 (12) | 131 (22) |
| Self-reported ICS use year before examination | |||
| No, n (%) | 420 (67) | 397 (65) | 425 (72) |
| When needed, n (%) | 129 (21) | 127 (21) | 105 (18) |
| Continuously, n (%) | 78 (12) | 91 (15) | 64 (11) |
| Elevated blood eosinophils ≥0.3×109 cells·L−1, n (%) | – | 144 (28) | 94 (20) |
| Elevated blood eosinophils 16 and/or 24 years, n (%) | – | 195 (32) | |
| Elevated FENO, ≥25 ppb, n (%) | – | 162 (30) | 111 (26) |
| Elevated FENO at 16 and/or 24 years, n (%) | – | 219 (35) | |
| Allergic sensitisation#, n (%) | 266 (50) | 349 (65) | 316 (64) |
| Height, cm, mean (sd) | 132 (6.2) | Male: 179 (7.4) Female: 167 (6.6) | Male: 182 (8.3) Female: 168 (6.5) |
| Weight, kg, mean (sd) | 30.5 (5.5) | Male: 70.4 (11.4) Female: 62.9 (11.2) | Male: 79.4 (14.5) Female: 67.0 (13.2) |
| BMI categories (IOTF at 8 and 16) | |||
| Under/normal weight, n (%) | 413 (75) | 427 (78) | 359 (72) |
| Overweight, n (%) | 108 (20) | 102 (19) | 96 (19) |
| Obese, n (%) | 27 (5) | 20 (4) | 41 (8) |
| Mean age in years (sd) | 8.45 (0.48) | 16.70 (0.39) | 22.61 (0.54) |
BMI: body mass index; FENO: fraction of exhaled NO; IgE: immunoglobulin E; IOTF: International Obesity Task Force. #: allergic sensitisation defined as IgE ≥0.35 kU·L−1 against mould, birch, cat, dog, horse, timothy, mugwort and/or house dust mite.