Aims: Smoking cessation treatment trials often require that smokers quit on or before a protocol-defined date. The goals of this paper were to: (1) identify factors associated with adherence to a protocol-defined quit date and (2) determine whether such adherence predicts cessation outcome (relapse).
Design: A quasi-experimental secondary analysis of data collected from a randomized placebo-controlled trial of fluoxetine (60 mg or 30 mg) versus placebo for smoking cessation.
Setting and participants: Clinic-based smoking cessation treatment program comprising 989 non-depressed smokers.
Intervention: Participants received cognitive behavioral therapy for smoking cessation and either study medication or placebo for 10 weeks. They were required to set a quit date within 2 weeks of their second study visit (by visit 4).
Findings: Significant predictors of quit date adherence were low nicotine dependence and active drug treatment. High-dose fluoxetine (60 mg) and male gender were protective against relapse. Adherence to quit date was not an independent predictor of relapse; instead there was a significant interaction between quit date adherence and gender. Among non-adherers to the quit date, women were more than 2.5 times as likely as men to relapse; among adherers to the quit date, women were only 1.3 times as likely as men to relapse.
Conclusions: Although women were more likely than men to relapse regardless of quit date adherence, adherence was strongly protective against relapse for women.