THE ROLE OF DOMESTIC FACTORS AND DAY-CARE ATTENDANCE ON LUNG-FUNCTIONOF PRIMARY-SCHOOL CHILDREN

The results of studies examining the relationship of domestic factors to lung function are contradictory. We therefore examined the independ ent effects of maternal smoking during pregnancy, exposure to environm ental tobacco smoke (ETS), the presence of a cat, type of heating and cooking used in the home and day-carl attendance on lung function afte r controlling for socioeconomic status (SES). Nine hundred and eighty- nine children from 18 Montreal schools were studied between April 1990 and November 1992. Information on the child's health and exposure to domestic factors was collected by questionnaire. Spirometry was perfor med at school. The data were analysed by multiple linear regression wi th percent predicted FEV1, FVC, and FEV1/FVC as dependent variables. I n the overall sample (both sexes combined), cat in the home (regressio n coefficient, beta= -1.15, 95% confidence interval, CI: - 2.26- - 0.0 5) and electric baseboard units (beta = - 1.26, 95% CI: -2.39- - 0.13) were independently associated with a lower FEV1/FVC, while day-care a ttendance (beta = - 2.05, 95% CI: - 3.71- - 0.40) significantly reduce d FEV1. Household ETS was significantly associated with increasing lev el of FVC (beta=2.86, 95% CI: +0.55 to +5.17). In boys but not girls, household ETS (beta= - 2.13, 95% CI: - 4.07- - 0.19) and the presence of a cat (beta= - 2.19, 95% CI: - 3.94- - 0.45) were associated with l ower FEV1/FVC. By contrast, day-care attendance was associated with lo wer FEV1 (beta= - 2.92, 95% CI: - 5.27- - 0.56) and FEV1/FVC (beta= - 1.53, 95% CI: - 2.73- - 0.33) in girls only. In conclusion, the result s provide evidence that domestic factors and day-care attendance prima rily affected airway caliber and gender differences were apparent in t he effects of these factors.