Comparative effectiveness of motivation phase intervention components for use with smokers unwilling to quit: a factorial screening experiment.

Aims: To screen promising intervention components designed to reduce smoking and promote abstinence in smokers initially unwilling to quit.

Design: A balanced, four-factor, randomized factorial experiment.

Setting: Eleven primary care clinics in southern Wisconsin, USA.

Participants: A total of 517 adult smokers (63.4% women, 91.1% white) recruited during primary care visits who were willing to reduce their smoking but not quit.

Interventions: Four factors contrasted intervention components designed to reduce smoking and promote abstinence: (1) nicotine patch versus none; (2) nicotine gum versus none; (3) motivational interviewing (MI) versus none; and (4) behavioral reduction counseling (BR) versus none. Participants could request cessation treatment at any point during the study.

Measurements: The primary outcome was percentage change in cigarettes smoked per day at 26 weeks post-study enrollment; the secondary outcomes were percentage change at 12 weeks and point-prevalence abstinence at 12 and 26 weeks post-study enrollment.

Findings: There were few main effects, but a significant four-way interaction at 26 weeks post-study enrollment (P = 0.01, β = 0.12) revealed relatively large smoking reductions by two component combinations: nicotine gum combined with BR and BR combined with MI. Further, BR improved 12-week abstinence rates (P = 0.04), and nicotine gum, when used without MI, increased 26-week abstinence after a subsequent aided quit attempt (P = 0.01).

Conclusions: Motivation-phase nicotine gum and behavioral reduction counseling are promising intervention components for smokers who are initially unwilling to quit.