Skip to main content

Table 1 Recruitment of the study population

From: Asthma in changing environments - chances and challenges of international research collaborations between South America and Europe - study protocol and description of the data acquisition of a case-control-study

  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:     
   Stool samples 138 73.4 137 46.6
   Blood samples 163 86.7 245 83.3
   Dust samplesb 112 59.6 188 63.9
  1. NA indicates not applicable
  2. a Indicating that people lived more than 100 km away from Valdivia
  3. b Dust samples from home visits