Exposure to environmental tobacco smoke is associated with increased respiratory morbidity in young children, but few studies have assessed such exposure objectively by urinary cotinine measurements. 501 children aged 1-5 years, a random 5% sample of children attending an outpatient clinic, were classified as exposed or non-exposed to environmental tobacco smoke with a cut-off of 10 ng cotinine per mg creatinine in urine. Exposed children were 3.5 times (95% CI 1.56-7.90, p < 0.0024) more likely to have increased respiratory morbidity (three or more episodes during the previous 12 months) than non-exposed children after adjustment for potential confounding factors.
Child, Preschool Confounding Factors, Epidemiologic