Longitudinal associations between substance use problem severity and relative harm perceptions of e‐cigarettes compared with cigarettes: Results from the United States Population Assessment of Tobacco and Health study (2013–2023)

AIMS: This study examines, among adults who smoke: (1) the association between the harm perception of e-cigarettes relative to cigarettes and substance use problem (SUP) severity, (2) whether changes in SUP severity over time are associated with changes in harm perceptions of e-cigarettes relative to cigarettes and (3) whether associations between harm perceptions and vaping initiation are moderated by SUP. DESIGN: Longitudinal study. SETTING: The study setting was the United States (US) with data from the Population Assessment of Tobacco and Health (PATH) study waves 1-7 collected between 2013 and 2023. PARTICIPANTS: The study population comprised non-institutionalized US adults (18+) who smoked cigarettes in the past month. MEASUREMENTS: The primary predictor for aims 1 and 2 was SUP severity. The outcomes at follow-up were: (1) relative harm perception of vaping compared with cigarette smoking [less harmful (accurate) versus more/same harm (inaccurate)], (2) change in SUP status (from no/low at baseline wave to moderate or high severity at follow-up) and change in relative harm perceptions (from inaccurate at baseline to accurate at follow-up). For aim 3, the primary predictor was relative harm perception, the outcome was nicotine vaping initiation and SUP was examined as a moderator. FINDINGS: A higher proportion and odds of respondents with high SUP (versus no/low SUP) had accurate harm perceptions [32.1% versus 28.5%; adjusted odds ratio (aOR) = 1.20; 95% confidence interval (CI) = 1.07-1.33]. Among individuals with no/low SUP at baseline with inaccurate perceptions, transitioning to high SUP at follow-up was associated with higher odds of developing accurate harm perceptions (aOR = 1.63; 95% CI = 1.19-2.25). Among those who smoked but had no prior history of vaping, at baseline transitioning from inaccurate to accurate harm perception at follow-up was associated with higher odds of vaping initiation (aOR = 2.08; 95% CI = 1.33-3.25). CONCLUSION: People who smoke and have high substance use problem severity appear to perceive vaping as less harmful than cigarette smoking. Notably, among those who smoke but have never vaped, transitioning from inaccurate to accurate perceptions was associated with vaping initiation.