Should all smokers use combination smoking cessation pharmacotherapy? Using novel analytic methods to detect differential treatment effects over 8 weeks of pharmacotherapy

Abstract

Introduction: Combination pharmacotherapy for smoking cessation has been shown to be more effective than monotherapy in meta-analyses. We address the question of whether combination pharmacotherapy should be used routinely with smokers or if some types of smokers show little or no benefit from combination pharmacotherapy versus monotherapy.

Methods: Two smoking cessation trials were conducted using the same assessments and medications (bupropion, nicotine lozenge, nicotine patch, bupropion + lozenge, and patch + lozenge). Participants were smokers presenting either to primary care clinics in southeastern Wisconsin for medical treatment (Effectiveness trial, N = 1,346) or volunteering for smoking cessation treatment at smoking cessation clinics in Madison and Milwaukee, WI (Efficacy trial, N = 1,504). For each trial, decision tree analyses identified variables predicting outcome from combination pharmacotherapy versus monotherapy at the end of treatment (smoking 8 weeks after the target quit day).

Results: All smokers tended to benefit from combination pharmacotherapy except those low in nicotine dependence (longer latency to smoke in the morning as per item 1 of the Fagerström Test of Nicotine Dependence) who also lived with a spouse or partner who smoked.

Conclusions: Combination pharmacotherapy was generally more effective than monotherapy among smokers, but one group of smokers, those who were low in nicotine dependence and who lived with a smoking spouse, did not show greater benefit from using combination pharmacotherapy. Use of monotherapy with these smokers might be justified considering the expense and side effects of combination pharmacotherapy.

Figure 1.

Importance scores for the all monotherapies and all combination treatment groups in the Effectiveness and Efficacy trials. Gray bars indicate that the importance scores of the variables are statistically significant in predicting follow-up smoking 8 weeks after the quit day. (See Table 2 for predictor variable definitions.)

Figure 2.

Importance scores for mono NRT and combination nicotine replacement therapy (NRT) in the Efficacy and Effectiveness trials. Gray bars indicate that the importance scores of the variables are statistically significant in predicting follow-up smoking 8 weeks after the quit day. (See Table 2 for predictor variable definitions.)