Table 1. Univariate analysis: variables associated with wheezing in the 12 months prior to the administration of the two questionnaires and showing p ≤ 0.25.

Variable	p
Birth weight (up to 2,499 g)	0.014
Day care center or nursery attendance	< 0.001
Maternal history of asthma	< 0.001
Current presence of birds in the home	0.021
Current presence of other animals in the home	0.108
Presence of pets in the home in the first year of life (dogs, cats, other furry animals, or birds)	0.047
Current contact with farm animals	0.187
Contact with animals outside the home (dogs, cats, or farm animals)	0.004
Contact with animals outside the home in the first year of life	0.038
Current maternal smoking	0.065
Smoking in the home by parents or other household members	0.194
Number of cigarettes smoked in the home by parents or other household members (> 20 cigarettes/day)	0.003
Current absence of windows in the bedroom	0.116
Current use of bedspreads/blankets as bed linen	0.118
Use of other materials as bed linen in the first year of life	0.105
Current area of residence (suburban residence with parks or urban residence without parks)	0.147