Comparative effectiveness of intervention components for producing long-term abstinence from smoking: a factorial screening experiment

Abstract

Aims: To identify promising intervention components that help smokers attain and maintain abstinence during a quit attempt.

Design: A 2 × 2 × 2 × 2 × 2 randomized factorial experiment.

Setting: Eleven primary care clinics in Wisconsin, USA.

Participants: A total of 544 smokers (59% women, 86% white) recruited during primary care visits and motivated to quit.

Interventions: Five intervention components designed to help smokers attain and maintain abstinence: (1) extended medication (26 versus 8 weeks of nicotine patch + nicotine gum); (2) maintenance (phone) counseling versus none; (3) medication adherence counseling versus none; (4) automated (medication) adherence calls versus none; and (5) electronic medication monitoring with feedback and counseling versus electronic medication monitoring alone.

Measurements: The primary outcome was 7-day self-reported point-prevalence abstinence 1 year after the target quit day.

Findings: Only extended medication produced a main effect. Twenty-six versus 8 weeks of medication improved point-prevalence abstinence rates (43 versus 34% at 6 months; 34 versus 27% at 1 year; P = 0.01 for both). There were four interaction effects at 1 year, showing that an intervention component's effectiveness depended upon the components with which it was combined.

Conclusions: Twenty-six weeks of nicotine patch + nicotine gum (versus 8 weeks) and maintenance counseling provided by phone are promising intervention components for the cessation and maintenance phases of smoking treatment.

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

© 2015 Society for the Study of Addiction.

Figures

Figure 1

CONSORT Diagram Note: S = Randomized to Standard 8 Weeks of Nicotine Patch + Nicotine Gum; Ex = Randomized to Extended 26 Weeks of Nicotine Patch + Nicotine Gum. See Supplemental Materials for reasons participants withdrew from the study

Figure 2

A Significant Interaction from the 7-Day Point-Prevalence Abstinence Outcome Models: Medication Adherence Counseling (MAC) × Automated Adherence Calls Interaction (Significant at Week 26 and Week 52)

Figure 3

An Interaction from the 7-Day Point-Prevalence Abstinence Outcome Models: Automated Adherence Calls × Helping Hand (HH) Counseling (Week 26 Unadjusted Model p=.07 and Adjusted Model p=.047; Significant at Week 52 in Both the Unadjusted and Adjusted Models)

Figure 4

An Interaction from the 7-Day Point-Prevalence Abstinence Outcome Models: Extended Medication (26 vs. 8 Weeks of Combination NRT [Nicotine Replacement Therapy]) × Medication Adherence Counseling (MAC) × Adherence Calls Interaction (Week 26 Unadjusted Model p=.050 and Adjusted Model p=.03; Significant at Week 52 in Both the Unadjusted and Adjusted Models)

Figure 5

A Significant Interaction from the 7-Day Point-Prevalence Abstinence Outcome Models: Maintenance Counseling × Medication Adherence Counseling (MAC) × Helping Hand (HH) Counseling (Significant at Week 26 and Week 52)

Figure 6

A Non-Significant Interaction from the 7-Day Point-Prevalence Abstinence Outcome Model at Week 52: Extended Medication × Maintenance Counseling × Medication Adherence Counseling (MAC) × Helping Hand (HH) Counseling (p=.053).