Assessments
We ascertained smoking status from baseline
and follow-up survey questions. Participants
at baseline were asked whether they
were current smokers, ex-smokers, or lifetime
nonsmokers. At follow-up, participants were
asked whether they smoked any cigarettes
since the baseline interview, and if so, how
often. The frequency was rated on an ordinal
scale ranging from once a month or less to
every day. Participants were also asked how
many cigarettes they smoked on the days on