The effect of placebo tailoring on smoking cessation: a randomized controlled trial

Previous research has found that smoking cessation messages can be designed to appear as tailored (placebo tailored) and result in superior outcomes compared to standard messages. In the current study, we aimed (a) to test the efficacy of placebo tailoring for smoking cessation and (b) to examine the influence of cognitive processing style.

In a 2-arm randomized controlled trial, 424 smokers (M = 19.66 cigarettes per day) from the community (57% female, 30% Caucasian, 40% African American, 29% Hispanic; mean age = 42 years) were randomly assigned to receive 4 placebo-tailored booklets or 4 standard booklets over 3 months. Participants completed a measure of systematic versus heuristic cognitive processing style at baseline. The primary outcome was 7-day point prevalence abstinence (ppa). Twenty-eight-day continuous abstinence, content evaluations, and readiness to quit were secondary outcomes. We hypothesized that placebo tailoring would be superior to standard materials and that the effect would be moderated by cognitive processing style (systematic and heuristic).

As expected, placebo tailoring led to greater 7-day ppa at 3 months and greater 28-day continuous abstinence at 6 months. Cognitive processing style moderated the effect on 7-day ppa, such that the placebo-tailored booklets produced greater cessation among participants with heuristic information processing tendencies.

Findings support a causal role of placebo tailoring for short-term smoking cessation, particularly for individuals who process information using heuristic strategies. Implications for tailored interventions are discussed.