Basic characteristics of the subjects
| Nonfarmers not living on a farm | Nonfarmers living on a farm | Farmers | p‐value | |
| Subjects n | 218 | 50 | 198 | |
| Age yrs | 39.3 (38.6–40.1) | 41.4 (39.7–43.2) | 41.3 (40.5–42.1) | 0.001 |
| BMI kg·m−2 | 25.2 (24.6–25.7) | 25.5 (24.5–26.5) | 25.6 (25.0–26.3) | 0.55 |
| Skin-test positivity | 36 | 35 | 36 | 0.97 |
| Smoking ever | 34 | 16 | 20 | 0.002 |
| Length of education yrs | 12.9 (12.5–13.3) | 13.8 (13.0–14.5) | 13.0 (12.6–13.4) | 0.13 |
| Having cats or dogs indoors currently | 34 | 46 | 57 | <0.001 |
| Parenteral atopy | 41 | 34 | 40 | 0.68 |
| Number of older siblings | 1.7 (1.5–1.9) | 1.7 (1.1–2.2) | 2.0 (1.7–2.3) | 0.30 |
| Childhood farming environment | 48 | 62 | 71 | <0.001 |
| Pets during childhood | 72 | 65 | 81 | 0.04 |
| Passive smoking during childhood | 69 | 58 | 56 | 0.02 |
| Allergic dermatitis during childhood | 22 | 28 | 22 | 0.64 |
| Childhood daycare attendance | 3.2 | 2.0 | 1.0 | 0.30 |
Data are presented as mean (95% confidence interval) or per cent, unless otherwise stated
The continuous variables were compared by analysis of variance between the groups
The categorical variables were compared between groups using the Chi-squared test
BMI: body mass index