Identifying effective intervention components for smoking cessation: a factorial screening experiment

AIMS: To identify promising intervention components intended to help smokers to attain and maintain abstinence in their quit smoking attempts. DESIGN: A fully crossed, six-factor randomized fractional factorial experiment. SETTING: Eleven primary care clinics in southern Wisconsin, USA. PARTICIPANTS: A total of 637 adult smokers (55% women, 88% white) motivated to quit smoking who visited primary care clinics. INTERVENTIONS: Six intervention components designed to prepare smokers to quit, and achieve and maintain abstinence (i.e. for the preparation, cessation and maintenance phases of smoking treatment): (1) preparation nicotine patch versus none; (2) preparation nicotine gum versus none; (3) preparation counseling versus none; (4) intensive cessation in-person counseling versus minimal; (5) intensive cessation telephone counseling versus minimal; and (6) 16 versus 8 weeks of combination nicotine replacement therapy (nicotine patch + nicotine gum). MEASUREMENTS: Seven-day self-reported point-prevalence abstinence at 16 weeks. FINDINGS: Preparation counseling significantly improved week 16 abstinence rates (P = .04), while both forms of preparation nicotine replacement therapy interacted synergistically with intensive cessation in-person counseling (P < 0.05). Conversely, intensive cessation phone counseling and intensive cessation in-person counseling interacted antagonistically (P < 0.05)-these components produced higher abstinence rates by themselves than in combination. CONCLUSIONS: Preparation counseling and the combination of intensive cessation in-person counseling with preparation nicotine gum or patch are promising intervention components for smoking and should be evaluated as an integrated treatment package.