Objective To examine parents' reported knowledge
and use of harm reduction strategies to protect their
infants from exposure to tobacco smoke in the home,
and the relation between reported use of strategies
and urinary cotinine to creatinine ratios in the infants.
Design Cross sectional survey.
Settings Coventry and Birmingham.
Main outcome measures Parents’ reported
knowledge and use of harm reduction strategies and
urinary cotinine to creatinine ratios in their infants.
Participants 314 smoking households with infants.
Results 86% of parents (264/307) believed that
environmental tobacco smoke is harmful, 90%
(281/314) believed that infants can be protected from
it in the home, and 10% (32/314) were either unaware
of measures or reported using none. 65% of parents
(205/314) reported using two or more measures, but
only 18% (58/314) reported not allowing smoking in
the home. No difference was found in mean log e
transformed urinary cotinine to creatinine ratio in
infants from households that used no measures
compared with households that used less strict
measures. Mean log cotinine to creatinine ratios were
significantly different in households banning smoking
in the home compared with those using less strict or
no measures. Banning smoking in the home was
independently associated with a significant reduction
in urinary cotinine to creatinine ratio by a factor of
2.6 (1.6 to 4.2) after adjustment for average household
cigarette consumption, tenure, and overcrowding.
Conclusions Less than a fifth of parents in smoking
households ban smoking in the home. Banning
smoking was associated with a small but significant
reduction in urinary cotinine to creatinine ratio in
infants, whereas less strict measures compared with
no measures had no effect on the infants’ exposure to
environmental tobacco smoke