Source: Wiley InterScience
Date: 2010-02-05
Author:  Sunni A. Barnes. 2010; Addiction

Aim 

A sizable percentage of subjects do not respond to follow-up
attempts in smoking cessation studies. The usual procedure in the
smoking cessation literature is to assume that non-respondents
have resumed smoking. This study used data from a study with a
high follow-up rate to assess the degree of bias that may be
caused by different methods of imputing missing data.
. . .


Findings 

The most important predictors of SHS exposure were modifiable
factors—whether people smoke in the house on most days, whether
the parents smoke and whether the children are looked after by
carers who smoke. Children from more deprived households were
more exposed and this remained the case even after parental
smoking status has been controlled for. Exposure over time has
fallen markedly among children (59% decline over 11 years in
geometric mean cotinine), with the most marked decline observed
in the period immediately preceding smoke-free legislation.
Declines in exposure have generally been greater in children most
exposed at the outset. For example, in children whose parents
both smoke, median cotinine declined annually by 0.115 ng/ml
compared with 0.019 ng/ml where neither parent smokes (P <
0.05).

Conclusions 

In the 11 years leading up to smoke-free legislation in England,
the overall level of SHS exposure in children as well as absolute
inequalities in exposure have been declining. Further efforts to
encourage parents and carers to quit and to avoid smoking in the
home would benefit child health.