Table 2 Details of follow-up of the first 18 months of the cohort study
| Â | Number of children invited to perform measurement | Number of children that performed measurement |
|---|---|---|
Questionnaire | Â | Â |
   Baseline – symptoms and QoLa | 771 | 718 (93.1) |
   Follow-up at 6 months – QoLa | 755 | 643 (85.2) |
   Follow-up at 12 months – symptoms and QoLa | 707 | 551 (77.9) |
   Follow-up at 18 months – QoLa | 610 | 450 (73.8) |
Total and specific IgE measurement b | 771 | 670 (86.9) |
NO-measurements c | 131 | 114 (87.0) |
PEF-measurements d | 131 | 117 (89.3) |