Evaluation of a home-based intervention program to reduce infant passive smoking and lower respiratory illness.

We conducted a randomized controlled trial to determine whether a home-based intervention program could reduce infant passive smoking and lower respiratory illness. The intervention consisted of four nurse home visits during the first 6 months of life, designed to assist families to reduce the infant's exposure to tobacco smoke. Among the 121 infants of smoking mothers who completed the study, there was a significant difference in trend over the year between the intervention and the control groups in the amount of exposure to tobacco smoke; infants in the intervention group were exposed to 5.9 fewer cigarettes per day at 12 months. There was no group difference in infant urine cotinine excretion. The prevalence of persistent lower respiratory symptoms was lower among intervention-group infants of smoking mothers whose head of household had no education beyond high school: intervention group, 14.6%; and controls, 34.0%.

Lung function in school-age children who had mild lower respiratory illnesses in early childhood.

We examined the relationship between patterns of mild lower respiratory illness (LRI) experienced in early childhood and lung function in 89 boys and 70 girls 6 to 18 yr of age. The children's histories of outpatient visits for wheezing and nonwheezing LRI during the first 6 yr of life had been documented by physicians in a single pediatric practice. Most children were reported by their parents to have been free of recurrent respiratory symptoms during the 2 yr prior to lung function testing. In sex-specific analyses, average lung function assessed by spirometry was similar in children who had made zero or one physician visit for wheezing LRI during the preschool years. Boys who had experienced two or more episodes of wheezing LRI during the preschool years had lower average FEV1, FEV1/FVC, FEF25-75, Vmax50, and Vmax75 than did boys who had zero or one preschool wheezing illness. The association between recurrent preschool wheezing LRI and later lung function remained after exclusion of data from seven boys who were reported to have wheezed in the 2 yr prior to study. Girls who had experienced two or more preschool wheezing LRI had lower average FEF25-75 and Vmax50 than girls with a history of zero or one such illness, but differences were not statistically significant. Recurrent nonwheezing LRI during the preschool years was not significantly associated with subsequent lung function in either sex, regardless of preschool wheezing LRI history. Detailed information concerning early childhood LRI experience is valuable in epidemiologic studies of factors influencing lung function in children.

Passive smoking during the first year of life.

BACKGROUND AND PURPOSE: A description of passive smoking during the first year of life might assist planning preventive efforts. METHODS: Changes in the ecology of passive smoking were investigated in a sample of infants in central North Carolina followed from birth to one year of age. RESULTS: The prevalence of tobacco smoke absorption, indicated by excretion of cotinine, increased from 53 percent to 77 percent (95% CI of difference: 14, 35) during the first year of life. Most infants (92 percent) excreting cotinine at three weeks of age were also excreting it at one year. Moreover, 61 percent of infants not excreting cotinine at age three weeks were excreting it at one year. This increase reflected an increased exposure to household and, particularly, nonhousehold sources of smoke; the proportion of infants exposed to nonhousehold smokers increased from 14 percent to 36 percent. CONCLUSIONS: These findings suggest that prevention of the onset of passive smoking should begin very early.

Ecology of passive smoking by young infants.

This study provides a detailed description of passive smoking by 433 infants (mean age 18 days) enrolled from a representative population of healthy neonates in central North Carolina during 1986 and 1987. Sixty-four percent (276) lived in households with smokers or had contact with nonhousehold smokers. During the week before data collection, two thirds (184) of these 276 infants reportedly had tobacco smoke produced in their presence. Seventy-five percent of smoking mothers smoked near their infants. The amount smoked by the mother near the infant correlated with the amount smoked near the infant by nonmaternal smokers. Cotinine, an indicator of smoke absorption, was found in the urine of 60% (258) of all study infants. The amount smoked in the infant's presence, as well as the amount smoked farther away from the infant, especially by the mother, were the most significant correlates of the urine cotinine concentration. The results of this study suggest that efforts to reduce passive smoking in young infants should emphasize the importance of the mother's smoking behavior, smoke produced anywhere in the home, and household social influences on smoking behavior near the infant.