Table 2—

Prevalence and odds ratios(OR) comparing farm# and nonfarm subjects for respiratory symptoms, asthma and allergic rhinitis, sensitisation, bronchial hyperresponsiveness (BHR) and lung function

Subjects nPrevalenceOR (95% CI)
UnadjustedAdjusted
Allergic rhinitis
 Nonfarm918167 (18.2)11
 Farm67764 (9.5)0.47 (0.35–0.64)0.54 (0.39–0.75)
Sensitisation SX1 >0.35
 Nonfarm918250 (27.2)11
 Farm677130 (19.2)0.64 (0.50–0.81)0.73 (0.57–0.94)
Wheezing without a cold
 Nonfarm918111 (12.1)11
 Farm67756 (8.3)0.66 (0.47–0.92)0.73 (0.51–1.04)
 With sensitisation
  Nonfarm85447 (5.5)11
  Farm64322 (3.4)0.61 (0.36–1.02)0.72 (0.42–1.23)
 Without sensitisation
  Nonfarm87164 (7.4)11
  Farm65534 (5.2)0.69 (0.45–1.06)0.73 (0.46–1.15)
Asthma diagnosis+
 Nonfarm91856 (6.1)11
 Farm67723 (3.4)0.54 (0.33–0.89)0.65 (0.39–1.08)
 With sensitisation
  Nonfarm90341 (4.5)11
  Farm66713 (2.0)0.42 (0.22–0.79)0.50 (0.26–0.96)
 Without sensitisation
  Nonfarm87715 (1.7)11
  Farm66410 (1.5)0.88 (0.39–1.97)1.05 (0.46–2.43)
BHR§
 Nonfarm918308 (33.6)11
 Farm677211 (31.2)0.90 (0.73–1.11)1.01 (0.81–1.27)
 With sensitisation
  Nonfarm731121 (16.6)11
  Farm52458 (11.1)0.63 (0.45–0.88)0.77 (0.54–1.10)
 Without sensitisation
  Nonfarm797187 (23.5)11
  Farm619153 (24.7)1.07 (0.84–1.37)1.15 (0.88–1.49)
Lung function
 Tiffeneau index % pred
  Nonfarm91599.9 (0.24)00
  Farm67399.7 (0.26)-0.20 (-0.91–0.50)-0.21 (-0.93–0.51)
  • Data are presented as n or n (%), with the exception of lung function which is presented as % (se) and unadjusted and adjusted mean difference (95% CI). SX1: an allergy screening test; % pred: % predicted. #: lived on a farm in the first 3 yrs of life; : did not live on a farm in the first 3 yrs of life; +: ever diagnosed by a physician; §: defined by a decrease in forced expiratory volume in one second >20% after methacholine challenge (≤0.6 mg). ORs are shown unadjusted and adjusted for sex, age, passive and active smoke exposure, education level, family history of allergic disease and presence of siblings.