The research findings were released online this week in advance of publication in the October print issue of the journal Pediatrics.
Overall in the United States, roughly one-third of children live in a home with a smoker, according to an earlier study by Dr. Jonathan P. Winickoff, assistant professor of pediatrics at Harvard Medical School and a co-author of the new research.
More than half of all children in the United States aged 3 to 11 have detectable levels of cotinine in their blood, a chemical caused by second-hand smoke, according to the authors.
The study looked at records, culled from the 2005 National Health Interview Survey, of more than 3,000 children aged 6 to 11 years. About 14 percent of the children in the study lived with someone who smoked at home.
The average annual income of families in the study was $20,087. Single parents headed 22 percent of the households with smokers.
The data was adjusted to account for factors that could affect school attendance, including socioeconomic class, family structure, race and gender. But it still showed that children of smokers missed more school time than their peers, and that about one-quarter to one-third of all class time they missed was due to illness connected to second-hand smoke.
The researchers also found that in homes where two parents or caregivers smoked, the children missed even more school time than in homes where only one parent smoked.
Children of smokers were more likely to have had either a chest cold in the two weeks before they were surveyed or more than three ear infections in the prior year, although the investigators found no link to a higher rate of vomiting or diarrhea.
The study found no link between parents' smoking at home and asthma. But only a small portion of children in the study had asthma, making it statistically unlikely that a connection would be fou
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