Study objective: To determine what factors predict
cotinine levels in US children.
representative sample of 5,653 US children, both with and without
reported tobacco smoke exposure in their homes.
Methods: We stratified the children into those with
reported passive smoke exposure at home and those without this
exposure. We used regression models to predict the log of the cotinine
level of the participants with the following independent covariates:
age; race/ethnicity; number of rooms in the home; sex; parental
education; family poverty index; family size; region; and, among
children with reported passive smoke exposure, the number of cigarettes
smoked in the home.
Results: Children exposed to
passive smoke had a mean cotinine level of 1.66 ng/mL, and children not
exposed to passive smoke had a mean level of 0.31 ng/mL. Among children
with reported smoke exposure, non-Mexican-American race/ethnicity,
young age, low number of rooms in the home, low parental education, and
an increasing number of cigarettes smoked in the home were predictors
of increased serum cotinine levels. Among children with no reported
smoke exposure, significant predictors of increased cotinine levels
included black race, young age, Midwest region of the United States,
low number of rooms in the home, low parental education, large family
size, and low family poverty index.
the reported number of cigarettes smoked in the home is the most
important predictor of cotinine levels in children exposed to smoke and
may provide an opportunity for clinical intervention, other demographic
factors are important among children both with and without reported