Objectives: To identify predictors of smoking abstinence at the end of medi
cation use that could assist in the optimal use of a sustained-release (SR)
form of bupropion for treating cigarette smokers,
Design: A double-blind, placebo-controlled, dose-response trial,
Setting: Multicenter (three sites) study conducted in the United States.
Participants: Six hundred fifteen healthy men and women (greater than or eq
ual to 18 years of age) who were smoking greater than or equal to 15 cigare
ttes per day and who were motivated to stop smoking,
Intervention: Random assignment of patients to placebo or SR bupropion trea
tment, 100, 150, or 300 mg/d, for 7 weeks (total duration of study was 52 w
eeks: 7 weeks of treatment and 45 weeks of follow-up).
Measurements and results: Logistic regression was used to identify predicto
rs of abstinence at the end of the medication phase. Univariate predictors
included the following: bupropion dose (p < 0.001); older age (p = 0.024);
lower number of cigarettes smoked per day (cpd) (p < 0.001); lower Fagerstr
om Tolerance Questionnaire score (p = 0.011); longest time previously absti
nent that was < 24 h or > 4 weeks (p < 0.001); absence of other smokers in
the household (p = 0.021); greater number of previous stop attempts (p = 0.
019); and study site (p = 0.004). Multivariate predictors of abstinence at
the end of the medication phase were the following: higher bupropion dose (
p < 0.001); lower number of cpd (p < 0.001); longest time previously abstin
ent from smoking (p = 0.002); male gender (p = 0.014); and study site(p = 0
.021).
Conclusion: Bupropion SR therapy was effective in treating cigarette smoker
s independently of all other characteristics studied. Lower smoking rate, b
rief periods (ie, < 24 h) or long periods (ie, > 4 weeks) of abstinence wit
h previous attempts to stop smoking, and male gender mere predictive of bet
ter outcomes, independent of the dose of bupropion that was used.