E-cigarette puffs per day and changes in cigarettes per day among combustible cigarette smokers with opioid use disorder: A secondary analysis of the Electronic Cigarettes to Address Combustible Cigarette Smoking for People With opioid use disorder (ERASER) study.

Electronic cigarettes (ECs) represent a promising harm reduction strategy among people with opioid use disorder who smoke. Prior research has shown that reducing cigarettes per day by at least 50% is associated with reduced morbidity. We tested whether the number of EC puffs per day is associated with achieving a ≥50% reduction in cigarettes per day among adults with opioid use disorder who smoke attempting to switch to ECs. A secondary data analysis of a 4-week trial testing ECs as a harm reduction tool among adults with opioid use disorder who smoke (N = 30). Daily EC puff counts were recorded using the study EC. Participants were categorized as reducers (n = 16) or nonreducers (n = 14) based on achieving a ≥50% reduction in cigarettes per day from baseline to Week 4. Longitudinal patterns of daily EC puff counts over the 4-week study were then compared between the two groups. A spline mixed-effect model (Bayesian information criterion = 1,527; Akaike information criterion = 1,469) identified changes in EC puffing during three phases: early (Days 1-9), middle (Days 10-18), and late (Days 19-28). Reducers showed an increase in EC puffs on early treatment days and maintained the number of EC puffs in the following two phases. Nonreducers showed a stable number of EC puff counts, followed by a decrease in the final treatment phase, b = -0.914; t(456.3) = -1.97. Distinct patterns of EC use were observed among reducers and nonreducers. These findings suggest that switching trials should consider incorporating increases in the daily number of EC puffs as a therapeutic target. (PsycInfo Database Record (c) 2026 APA, all rights reserved).