Longitudinal transition outcomes among adult dual users of e-cigarettes and cigarettes with the intention to quit in the United States: PATH Study (2013–2018)

Many adult dual users of e-cigarettes and cigarettes in the United States report using e-cigarettes with the intention to quit (ITQ) smoking. This study examined transition outcomes among adult dual users of e-cigarettes and cigarettes with the ITQ compared to mono cigarette smokers with ITQ. We conducted a longitudinal analysis of 3,542 adults aged ≥ 18 years with data from Waves 1 and 4 of the United States Population Assessment of Tobacco and Health study (2013–2018) between May 2021 and January 2022. Current dual users (e-cigarettes and cigarettes use on ≥ 20 days in the past month) with the ITQ were compared to current mono cigarette smokers with the ITQ for transition outcomes (cessation, mono e-cigarette, mono cigarette and dual use) three years later. We conducted multinomial logistic regression modeling adjusting for potential confounders and reported the adjusted relative risk ratios (aRRR) with 95% confidence intervals (CI) for the transition outcomes. Approximately 10.7% (7.8–14.3) of dual users with the ITQ (in 2013) reported cessation (no past-month use of any tobacco) three years later, compared to 16.1% (14.6–17.7) of mono cigarette smokers. Dual users were 83% and 79% less likely to transition to cessation (aRRR: 0.17, 95% CI:0.09–0.32) or mono cigarette use (0.21, 0.14–0.32), respectively, compared to mono cigarette smokers. Our findings show that in a real-world scenario, dual e-cigarette and cigarette use may hinder rather than facilitate smoking cessation among those interested in quitting. This needs consideration when assessing the population impact of e-cigarettes and their role in harm reduction.