| Cases | Controls | ||
---|---|---|---|---|
 | N | % | N | % |
Patients contacted | 424 | 100 | 749 | 100 |
Not eligible | 133 | 100 | 249 | 100 |
   Moved from urban to rural area or vice versa | 62 | 46.6 | 143 | 57.4 |
   Without parent/legal guardian | 19 | 14.3 | 33 | 13.3 |
   Place of living outside Valdivia regiona | 16 | 12.0 | 40 | 16.1 |
   Asthma diagnosis not confirmed by a physician | 29 | 21.8 | NA | NA |
   Not born in Chile | 1 | 0.8 | 3 | 1.2 |
   Mentally/physically disabled | 4 | 3.0 | 2 | 0.8 |
   Control patient reporting diagnosis of asthma | NA | NA | 24 | 9.6 |
   Other | 2 | 1.5 | 4 | 1.6 |
Eligible study population | 291 | 100 | 500 | 100 |
Non-responder | 53 | 100 | 173 | 100 |
   No interest | 21 | 39.6 | 90 | 52.0 |
   No time | 22 | 41.5 | 58 | 33.5 |
   General doubts | 9 | 17.0 | 12 | 6.9 |
   Other | 1 | 1.9 | 13 | 7.5 |
- Study population with complete interview and SPT data | 188 | 100 | 294 | 100 |
Participation in additional study parts: | Â | Â | Â | Â |
   Stool samples | 138 | 73.4 | 137 | 46.6 |
   Blood samples | 163 | 86.7 | 245 | 83.3 |
   Dust samplesb | 112 | 59.6 | 188 | 63.9 |