REV---:*,I 796 CONFIDEMA
    Subiect ref 8d
    "Do both paternal and maternal smoking influence the prevalence
    *Idhood asthma? A study into the prevalence of asthma
    of chil
    in children and t'6e effects of varental smoking"
    J Kay et al
    Journal of Asthma (1995), )j, 47-55
    This paper describes the results of a study carried out involvi-ng
    1077 children aged 3-11 registered with an urban general practice
    Bi=--ngham. A general practitioner interviewed the children and parents,
    and data were collected on presence and history of asthma and eczema. on
    days lost in the previous year from school (or day care), and on parental
    smoking habits and occupation.
    The main findings in relation to parental smoking are summarized in
    the table below.
    Parental smoking habits
    Neither Mother Father Both-
    smoked only only  smoked
    Total 626 142 178 131
    % asthr-atic children 17.3 19.0 21.3 29.0
    Total children with eczema 124 23 40 31
    % asth=atic 29.8 39.1 50.0 51.6
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    BATCo document for Legal Services: Health Canada 19 October 1999

    




    -2-
    As can be seen, there is a tendency for the frequency of asthma to
    rise with increasing parental smoking habits, though only when the
    parents both smoked was the frequency significantly (p<0.01) increased
    compared to when neither parent smoked.
    Eczema was not significantly related to parental smoking, but among
    children with eczema, asthma was considerably more CDMMon. In children
    with eczema, a relationship between prevalence of asthma and parental
    41 smoking was again seen, with incidence significantly (p<0,05) elevated if
    the father smoked or if both parents s=oked.
    Social class was very strongly related to smoking (see Table 3) but
    not to asthma (see Table 6). so confounding by social class apparently
    could not explain the smoking/asthma relationship.
    Results relating parental smoking to school absence were not
    presented, though asthmatic children were noted to have more days off
    than non-ast1=atic children.
    Taking into account =edlcall records (in a sample) revealed
    relatively few asthma cases which were not reported by the parents.
    The authors concluded that "pa:ental smoking appeared to increase
    the prevalence of asthma. This was more marked when both parents
    smoked."
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    BATCo document for Legal Services : Health Canada 19 October 1999

    




    While the res-.;lts are certainly consIstent with an effect of ETS
    exposure on asthma. the s:--.dy is limited by the failure to take into
    account any potenzial confounding factors at all. Factors ignored
    include age, race (which is very mixed in many parts of Birmingham),
    diet, exposure to allergens, heating and cooking types used, and presence
    of asthma and ot*-er respirar-ory d--seases in the parents. It thus adds
    little to the overall literature, which merits careful review. The
    softness of the criteria used to diagnose as:hma may a~so be a problem
    with the study.
    P N Lee
    7.6.95.
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    BATCo document for Legal Services : Health Canada 19 October 1999