Basic characteristics of the subjects
| Not living on a farm, n = 202 | Living on a farm, n = 231 | p Value | |
|---|---|---|---|
| *Due to the skewed distribution, Mann-Whitney U test was used. | |||
| The continuous variables are expressed as means and standard deviations in parenthesis, and compared by Student’s t test between the groups. The categorical variables are expressed as percentages, and the comparisons between the groups were carried out using Fisher’s exact test. | |||
| Mean (SD) age (years) | 39.2 (5.7) | 41.5 (5.7) | NS |
| Mean (SD) body mass index (kg/m2) | 25.2 (4.1) | 25.2 (3.9) | NS |
| Ex smokers (%) | 23 | 12 | 0.005 |
| Current smokers (%) | 10 | 5 | 0.047 |
| Mean (SD) length of education (years) | 13.0 (2.7) | 13.2 (2.7) | NS |
| Having cats or dogs indoors currently (%) | 34 | 55 | <0.0001 |
| Parental atopy (%) | 40 | 41 | NS |
| Mean (SD) number of older siblings | 1.8 (1.7) | 1.9 (2.0) | NS* |
| Childhood farming environment (%) | 49 | 70 | <0.0001 |
| Having had pets during childhood (%) | 73 | 78 | NS |
| Passive smoking during childhood (%) | 69 | 53 | 0.001 |
| Allergic dermatitis during childhood (%) | 23 | 22 | NS |
| Childhood day care attendance (%) | 2.0 | 1.7 | NS |