Family composition and children's exposure to adult smokers in their homes.

OBJECTIVE Smoking behavior is strongly influenced by the social environment. More information is needed about how the composition of households with children is associated with adult smoking behavior so that more effective interventions to reduce children's secondhand smoke exposure can be devised and implemented. METHODS Using data from the Medical Expenditure Panel Survey 2000-2004, we conducted cross-sectional analyses to assess how adult smoking behavior is associated with household characteristics, including the number of adults and smokers present, the relationship of the child to the head of household, and relationships between adult members of the household. RESULTS More than one third (34.4%) of children lived with > or =1 adult smoker. Almost half (49.4%) of poor children lived with a smoker, and they were more likely to live with multiple smokers compared with those who lived at >400% of the federal poverty level (21.2% vs 7.8%). Approximately 5 million children lived in households headed by an adult other than their parent, and they were significantly more likely to live with smokers: 53.4% of children who lived in their grandparents' homes and 46.2% of children in homes of other adults lived with at least 1 adult smoker, compared with 33.3% who lived in their parents' home. A total of 59.4% of all children who lived with a smoker had a smoking mother, and 56.7% of those children lived with > or =2 smokers, whereas only 17.0% of children whose mother did not smoke had smoking adults in the home. CONCLUSIONS These findings demonstrate the significant influence of household composition on children's likelihood to live in homes with adult smokers.