Effects of timing of initiation and planning on smoking cessation outcomes: study protocol for a randomised controlled trial

Recent theoretical and empirical work has led to debate over the benefit of delaying the implementation of a decision to quit smoking in order to plan the attempt. These two need not be linked, planning can occur before a commitment to quit is made, or after it is implemented, as well as in between. This study will test whether there are independent benefits for encouraging smokers to act immediately on a definite decision to quit smoking, and to engage in structured planning.

A complex randomised controlled trial with a factorial design, testing the presence of a recommendation to quit immediately (or not) and encouragement to structured planning (or not) as additions to standard care, a web-based automated tailored advice program (QuitCoach). Participants are recruited from users of the QuitCoach who reside in Australia, do not report a mental health condition for which they are taking medication, are adult daily smokers, and at least open to the possibility of quitting. For the Immediate arm they could not have committed to quit within 2 days, while the Planning arm included all these and those quit within the last 4 days. This creates 6 groups: 2 × 3, with 2 × 2 fully randomised, and 2 only randomised for the planning arm. Follow-up assessments are conducted around 1 month (targeting two weeks after the quit attempt started), and 6 months later. The primary outcome is 6-month sustained abstinence at 6 months. Secondary outcomes include point-prevalence abstinence at both follow-ups, and making quit attempts during the intervention period. We will also explore differences in actual behaviour (timing and planning) by intervention, and relate this to outcomes.

This study will result in a better understanding of the roles of planning and delay in influencing the success of quit attempts.

Australian New Zealand Clinical Trials Registry http://​ACTRN12612000613​808