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

Abstract

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.

Keywords: Chronic care smoking treatment; Multiphase Optimization Strategy (MOST); Phase-Based Model of smoking treatment; comparative effectiveness; factorial experiment; nicotine replacement therapy; primary care; smoking cessation; tobacco dependence.