Table 1 Characteristics of children enrolled in the study
| Â | Enrolled in the study (%) (n = 771) | Not enrolled in the study (%) (n = 1167) |
|---|---|---|
Sex | Â | Â |
   Male | 432 (56.0) | 630 (54.0) |
   Female | 339 (44.0) | 538 (46.1) |
Age at onset | Â | Â |
   1 | 267 (34.6) | 349 (29.9) |
   2 | 220 (28.5) | 343 (29.4) |
   3 | 127 (16.5) | 227 (19.5) |
   4 | 121 (15.7) | 203 (17.4) |
   5 | 36 (4.7) | 45 (3.9) |
Symptoms at onset | Â | Â |
   One respiratory symptom | 518 (67.2) | 897 (76.9) |
   Cough (2×) | 420 (54.5) | 763 (65.4) |
   Wheeze | 57 (7.4) | 83 (7.1) |
   Shortness of breath | 41 (5.3) | 51 (4.4) |
   Two respiratory symptoms | 195 (25.3) | 221 (18.9) |
   Wheeze and cough | 121 (15.7) | 150 (12.9) |
   Shortness of breath and cough | 55 (7.1) | 55 (4.7) |
   Shortness of breath and wheeze | 19 (2.5) | 16 (1.4) |
   Three respiratory symptoms | 58 (7.5) | 49 (4.2) |
   Shortness of breath, wheeze and cough | 58 (7.5) | 49 (4.2) |