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In two separate prospective cohorts, Davey Smith and colleagues have
found an association between height and non-smoking-related cancers. An
editorial supporting the papers indicates that causality for this
association is supported by animal work. No authors, however, examine the
possiblity of bias in the cohort studies from survival selection.
Cancer and heart disease are the main causes of death at older age,
but the mean age of death for heart disease is younger than for cancer.
Heart disease is strongly associated with smoking and also with short
stature. Is it possible that there is selective survival of taller people
because shorter people die earlier from heart disease? This hypothesis is
strengthened by the lack of association with smoking-related cancers -
smoking would be expected to cause heart disease first.
A test of this hypothesis would be to compare heights of groups of
heart disease and cancer deaths with the same mean age. Did the referee
ask for this? The two papers would be strengthened if the issue can be