Exploring the “Active Ingredients” of an Online Smoking Intervention: A Randomized Factorial Trial
Mené auprès de 1 865 fumeurs, cette étude évalue, du point de vue du taux d'abstinence tabagique ou du taux d'utilisation d'un traitement d'appoint à un an (pharmacothérapie ou conseil téléphonique), l'efficacité de quatre modalités d'interventions en ligne pour aider à arrêter de fumer
Introduction: Research needs to systematically identify which components increase online intervention effectiveness (i.e., “active ingredients”). This study explores the effects of 4 potentially important design features in an Internet-based, population-level smoking intervention. Methods: Smokers (n = 1,865) were recruited from a large health care organization, regardless of readiness to quit. Using a full factorial design, participants were randomized to 1 of the 2 levels of each experimental factor (message tone [prescriptive vs. motivational], navigation autonomy [dictated vs. not], e-mail reminders [yes vs. no], and receipt of personally tailored testimonials [yes vs. no]) and provided access to the online intervention. Primary outcomes were self-reported seven-day point-prevalent smoking abstinence and confirmed utilization of adjunct treatment (pharmacotherapy or phone counseling) available through the health plan at one year. Outcomes were also assessed at two and six months and were examined among all enrolled participants (intent-to-treat [ITT]) and all who viewed the intervention (modified ITT). Results: At one year, 13.7% were abstinent and 26.0% utilized adjunct treatment. None of the contrasting factor levels differentially influenced abstinence or treatment utilization at 12 months. In the modified ITT sample, smokers receiving testimonials were less likely to use adjunct treatment at six months (odds ratio = 0.54, 95% confidence interval = 0.30–0.98, p = .04). Conclusions: None of the design features enhanced treatment outcome. The negative effect observed for testimonials is provocative, but it should be viewed with caution. This study offers a model for future research testing the “active ingredients” of online interventions.