Characteristics and demographic data for the study population, according to childhood living environment
| Inner city, mean (SD) | Village/town/suburb, mean (SD) | Farm, mean (SD) | p Value* | |
|---|---|---|---|---|
| Mean age, years | 41.9 (7.2) | 42.6 (7.2) | 45.1 (6.4) | <0.001 |
| % (n) | % (n) | % (n) | ||
| Gender | ||||
| Male | 45.5 (1201) | 48.0 (2991) | 46.8 (432) | |
| Female | 54.5 (1441) | 52.0 (3239) | 53.3 (492) | 0.085 |
| Ever smoker | 57.4 (1512) | 56.3 (3505) | 54.3 (501) | 0.262 |
| Paternal smoking | 66.5 (1705) | 65.3 (3932) | 61.0 (541) | 0.019 |
| Maternal smoking | 27.8 (726) | 23.1 (1415) | 14.0 (128) | <0.001 |
| Cat in childhood | 32.2 (717) | 44.3 (2772) | 84.0 (743) | <0.001 |
| Dog in childhood | 30.1 (677) | 42.8 (2707) | 73.2 (655) | <0.001 |
| Older siblings | 53.4 (702) | 54.2 (2065) | 61.7 (409) | 0.001 |
| Bedroom sharing | 65.3 (1774) | 66.9 (4332) | 71.2 (666) | 0.005 |
| Family history of allergic disease | 37.9 (883) | 31.5 (1714) | 26.4 (218) | <0.001 |
| Serious respiratory infection <5 years | 12.2 (319) | 10.7 (649) | 12.1 (108) | 0.088 |
| School attendance <5 years | 50.3 (1124) | 36.2 (2288) | 18.4 (163) | <0.001 |
*Statistical significance determined by χ2 or analysis of variance.