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.

Conflict of interest statement

Declaration of Interest: This research was supported by grants 9P50CA143188 and 1K05CA139871 from the National Cancer Institute to the University of Wisconsin Center for Tobacco Research and Intervention and by the Wisconsin Partnership Program. Dr. Collins is also supported by NIH grants P50DA10075 and R01DK097364. This work was carried out in part while Dr. Schlam was a Primary Care Research Fellow supported by a National Research Service Award (T32HP10010) from the Health Resources and Services Administration to the University of Wisconsin Department of Family Medicine. Dr. Cook is also supported by Merit Review Award 101CX00056 from the US Department of Veterans Affairs. Dr. Loh is also supported by NSF grant DMS-1305725.

The authors have received no direct or indirect funding from, nor do they have a connection with, the tobacco, alcohol, pharmaceutical or gaming industries or anybody substantially funded by one of these organizations. Dr. Loh is partially supported by a grant from Eli Lilly and Company for research that is unrelated to smoking or tobacco dependence treatment.

Clinical Trial Registration: NCT01116986

© 2015 Society for the Study of Addiction.

Figures

Figure 1

CONSORT Diagram

Figure 2

Significant Interactions from the 7-Day Point-Prevalence Abstinence Models

Figure 2

Significant Interactions from the 7-Day Point-Prevalence Abstinence Models

Figure 2

Significant Interactions from the 7-Day Point-Prevalence Abstinence Models