A randomized controlled trial of a smoking cessation self-help intervention for dual users of tobacco cigarettes and E-cigarettes: Intervention development and research design.

Electronic Nicotine Delivery Systems, also called electronic cigarettes or e-cigarettes, have been available for over a decade and use has been increasing dramatically. The primary reported reasons for use are to aid smoking cessation or reduction, yet a significant proportion appear to be long-term users of both products ("dual users"). Dual users may be motivated to quit smoking and might benefit from a behavioral intervention for smoking cessation. This paper describes the intervention development, as well as the design, methods, and data analysis plans for an ongoing randomized controlled trial (RCT). Formative research and learner verification were conducted to create a usable, understandable, and acceptable self-help intervention targeting dual users. The efficacy is being tested in an RCT with current dual users (N=2900) recruited nationally and randomized to one of three conditions. The Assessment Only (ASSESS) group only completes assessments. The Generic Self-Help (GENERIC) group receives non-targeted smoking cessation booklets and supplemental materials sent monthly over 18months. The e-cigarette Targeted Self-Help (eTARGET) group receives the newly developed intervention (targeted booklets and supplemental materials) sent over the same period. All participants complete self-report surveys every 3months over 2years. The primary study outcome is self-reported 7-day point prevalence abstinence. Cost-effectiveness metrics for the GENERIC and eTARGET interventions will also be calculated.