Attrition during a randomized controlled trial of reduced nicotine content cigarettes as a proxy for understanding acceptability of nicotine product standards

Abstract

Aims To determine (1) if nicotine content affects study attrition – a potential behavioral measure of acceptability – in a trial that required compliance with three levels of reduced nicotine content (RNC) cigarettes, and (2) if attrition is associated with subjective and behavioral responses to RNC cigarettes. Design Secondary analysis of a 35-day, parallel design, open-label, randomized controlled trial. After a 5-day baseline period, participants were randomized to smoke for three, 10-day periods: their preferred brand (control group), or RNC cigarettes with three nicotine levels in a within-subject, stepdown (1 group: high-moderate-low) or non-stepdown (5 groups: high-low-moderate, low-moderate-high, low-high-moderate, moderate-low-high, moderate-high-low) fashion. Setting A single site in Philadelphia, Pennsylvania, USA. Participants 246 non-treatment-seeking daily smokers (M age = 39.52, CPD = 20.95, 68.3% White) were recruited from October 2007 to June 2013. Measurements The primary outcome was attrition. Key predictors were nicotine content transition and study period. Exploratory predictors were taste and strength subjective ratings, total puff volume, and carbon monoxide (CO) boost. Covariates included: age, gender, race, education, and nicotine dependence. Findings Overall attrition was 31.3% (n = 77): 24.1% of the control and 25.0% of the stepdown RNC cigarette groups dropped out vs. 44.6% of non-stepdown groups (p = 0.006). Compared with controls, attrition odds were 4.5 and 4.7 times greater among smokers transitioning from preferred and the highest RNC cigarettes to the lowest RNC cigarettes, respectively (p’s = .001 and .003). Providing more favorable initial taste ratings of study cigarettes decreased attrition odds by 2% (p = .012). Conclusions The majority of participants completed a 35-day trial of varying levels of reduced nicotine content cigarettes. Participant drop-out was greater for cigarettes with lower nicotine content and less in smokers reporting more favorable subjective ratings of the cigarettes.

Current advances in research in treatment and recovery: Nicotine addiction

“…In clinical trials, VLNCs generally have lower acceptability than commercially available cigarettes, and these trials have encountered problems with nonadherence (with upward of 70% of participants substituting traditional cigarette brands for VLNCs) and study dropout rates of 25 to 45% ( 229 , 230 ). Combining VLNCs with nicotine patches may aid with the transition to VLNCs and increase compliance, but doing so was not found to improve long-term quit rates.…”

Nicotine Reduction in Cigarettes: Literature Review and Gap Analysis

“…Despite this, we were able to pick up where previous reviews left off, 10,11 thereby avoiding duplication of effort. Third, some studies in this review were limited by participant noncompliance or differential attrition, 20,67,73,74 and several studies reported on validation of measures to most accurately assess compliance in future studies. 20,67,71,74 Fourth, although an ultimate goal is to quantify risk of VLNCs, this initial paper was intended to provide an overview of the framework and the published literature, so future review of subsets of these data will be meta-analyzed where possible.…”

A Novel Method for Evaluating the Acceptability of Substitutes for Cigarettes: The Experimental Tobacco Marketplace

“…However, prior studies suggest concordance between estimates from hypothetical purchase tasks and consumption patterns. 18,21–23 Regardless, future studies that test the predictive validity of the ETM will further delineate the utility of this novel approach. Prospective studies are required to see if this sophisticated method provides more accurate prediction of changing behavior than simpler methods such as simply asking the person how likely they are to use a product.…”

“…Product acceptability, as measured by study retention, was lower for smokers randomized to abruptly transition to VLNCs and for those who rated taste less favorably. 23 In the largest clinical trial of VLNCs, participants randomized to receive 6 weeks of VLNCs (≤ 2.4 mg/g) reported a reduction in estimated consumption of study cigarettes relative to those provided normal nicotine content cigarettes (15.8 mg/g). 21 Future studies should examine how ETM purchasing patterns change over time as a function of product use, which may improve the accuracy of substitution estimates.…”