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

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.