Predictors of smoking reduction among African American and Latinx smokers in a randomized controlled trial of JUUL e-cigarettes.

INTRODUCTION: E-cigarette (e-cig) use is widespread and may play an important role in facilitating smoking reduction. Racial/ethnic minorities are less likely than Whites to use e-cigs and suffer disproportionate tobacco-related disease, making them a priority for harm reduction. This paper explores factors associated with smoking reduction among African American (AA) and Latinx smokers enrolled in a trial assessing toxicant exposure in those assigned to e-cigs or smoking as usual. METHODS: Participants were randomized to receive 6 weeks of JUUL e-cigs or continue smoking cigarettes as usual (N = 187). This analysis focuses on 109 participants randomized to e-cigs. We modeled cigarettes smoked in the past week at baseline and week 6 as a function of a priori selected predictors (number of JUUL pods used throughout the study, baseline cigarette dependence, and baseline cotinine) using a Poisson model fit with generalized estimating equations. RESULTS: Over the six-week study, cigarette smoking decreased from an average of 82.4 to 15.5 cigarettes per week. Greater numbers of JUUL pods used predicted a greater smoking reduction by week 6 (IRR = 0.94 [0.91, 0.96], p < 0.001). Higher baseline cigarette dependence (IRR = 1.03 [1.01, 1.05], p = 0.004), and baseline cotinine (IRR = 1.18 [1.03, 1.37], p = 0.020) predicted a lesser smoking reduction. CONCLUSIONS: AA and Latinx smokers reduced their cigarette consumption while using JUUL e-cigs. Higher e-cig use during an intervention to switch to e-cigs to reduce harm may facilitate a transition to smoking fewer cigarettes, offering an opportunity to narrow smoking-related health disparities.