Objectives: To identify predictors of smoking
abstinence at the end of medication use that could assist in the
optimal use of a sustained-release (SR) form of bupropion for treating
Design: A double-blind,
placebo-controlled, dose-response trial.
Multicenter (three sites) study conducted in the United States.
Participants: Six hundred fifteen healthy men and women
(≥ 18 years of age) who were smoking ≥ 15 cigarettes per day and
who were motivated to stop smoking.
Random assignment of patients to placebo or SR bupropion treatment,
100, 150, or 300 mg/d, for 7 weeks (total duration of study was 52
weeks: 7 weeks of treatment and 45 weeks of follow-up).
Measurements and results: Logistic regression was used to
identify predictors 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 Fagerström Tolerance
Questionnaire score (p = 0.011); longest time previously abstinent
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 abstinent 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 smokers independently of all other
characteristics studied. Lower smoking rate, brief periods
(ie, < 24 h) or long periods (ie, > 4
weeks) of abstinence with previous attempts to stop smoking, and male
gender were predictive of better outcomes, independent of the dose of
bupropion that was used.