Who Enrolled in a Randomized Controlled Trial of Quitline Support? Comparison of Participants Versus Nonparticipants

Introduction: Understanding the characteristics of smokers who enroll in a trial of quitline support and those who decline could guide recruitment approaches and service delivery to better engage smokers and increase successful quitting. However, it is unknown whether factors such as smokers' perceived effectiveness of using quitting aids or self-exempting beliefs are associated with quitline uptake. We compared the sociodemographic characteristics, smoking behaviours, perceived effectiveness of using quitting aids, and self-exempting beliefs of participants and nonparticipants who were actively telephoned and offered quitline support as part of a randomized controlled trial. Methods: Overall, 48,014 telephone numbers were randomly selected from the electronic telephone directory and contacted. A total of 3,008 eligible smokers were identified and invited to participate in a trial of quitline support. Consenting trial participants (n = 1,562) and nonparticipants (n = 500) completed a baseline interview. Results: Multivariate analysis showed that the following factors were associated with trial participation: consumption of 21 or more cigarettes per day (odds ratio [OR] = 1.45 [1.07-1.99]), readiness to quit within 30 days (OR = 4.45 [3.20-6.19]) or 6 months (OR = 3.22 [2.46-4.23]), perceiving that calling the quitline was definitely (OR = 2.34 [1.62-3.39]) or partly effective (OR = 2.15 [1.63-2.83]), believing that using self-help materials was partly effective (OR = 1.50 [1.16-1.94]), thinking that nicotine replacement therapy was partly effective (OR = 1.38 [1.04-1.84]), perceiving that using willpower alone was partly (OR = 1.99 [1.48-2.67]) or not effective (OR = 2.60 [1.95-3.46]), and not holding a self-exempting belief (OR = 1.45 [1.11-1.89]). Conclusions: Increasing smokers' utilization of quitlines is likely to require changing their perceptions of the effectiveness of quitting strategies compared with using willpower alone and addressing self-exempting beliefs.