Longitudinal association between harm perceptions and tobacco behaviors among adults who smoke cigarettes: Differential associations across age groups using the PATH study.

INTRODUCTION: The relationship between e-cigarette and cigarette harm perceptions and tobacco behaviors may vary by age. We examined longitudinal associations of harm perceptions with tobacco use behaviors among adults who smoke cigarettes. METHODS: Data were from Waves 4 (2016-2018) and 5 (2018-2019) of the Population Assessment of Tobacco and Health survey. Weighted multivariable logistic regressions identified independent associations between relative and absolute e-cigarette and cigarette harm perceptions at baseline and continued smoking, dual use, complete switching, and quit intention at follow-up, stratified by age (young adults [YAs] 18-24, middle-aged adults [MAs] 25-44, and older adults [OAs] ≥45) among U.S. adults who smoke (n=8,231). RESULTS: Perceiving e-cigarettes as less harmful than cigarettes was associated with higher odds of complete switching from cigarettes to e-cigarettes (aORs overall: 1.52; MAs: 1.68). Perceiving e-cigarettes as very/extremely harmful was associated with lower odds of dual use (overall aOR: 0.75; MAs: 0.72) and higher odds of quit intention (aOR among OAs: 1.34). Perceiving cigarettes as very/extremely harmful was associated with lower odds of continued smoking (overall aOR: 0.69; MAs: 0.76; OAs: 0.53), and higher odds of complete switching (overall aOR: 1.65; MAs: 1.86) and quit intention (overall aOR: 1.58; MAs: 1.42; OAs: 1.80). No findings reached significance for YAs. DISCUSSION: E-cigarette relative and absolute harm perceptions were associated with different tobacco behaviors by age. Low cigarette harm perceptions were similarly associated with continued smoking and lower quit intentions in MAs and OAs. Future research should explore what beliefs inform these perceptions and age-related differences. IMPLICATIONS: The associations between harm perceptions and subsequent tobacco behaviors differed by age among adults who smoke. This study adds that low relative harm perceptions of e-cigarettes can promote complete switching among MAs who smoke. High absolute harm perceptions of e-cigarettes may deter dual use among MAs. Additionally, high absolute harm perceptions of cigarettes may reduce smoking and increase cigarette smoking quit intentions among MAs and OAs. Future research is needed to understand the beliefs that support harm perceptions among different age groups and why their effects differ by age, and what factors influence YAs' tobacco use behaviors.

Perceptions about levels of harmful chemicals in e-cigarettes relative to cigarettes, and associations with relative e-cigarette harm perceptions, e-cigarette use and interest.

BACKGROUND AND AIMS: Exposure to chemicals contributes to harm from nicotine products, and e-cigarette communications often refer to chemicals. However, while e-cigarette studies commonly measure perceived harmfulness of e-cigarettes relative to cigarettes, few have assessed comparative perceptions about chemicals. This study measured perceived levels of harmful chemicals in e-cigarettes compared with cigarettes and associations with e-cigarette/cigarette relative harm perceptions, e-cigarette use and interest. DESIGN, SETTING AND PARTICIPANTS: This was an on-line cross-sectional survey of adults/young adults from a nationally representative research panel in the United States conducted in January 2021. Participants were independent samples of 1018 adults who smoked cigarettes and 1051 young adult non-smokers (aged 18-29 years). MEASUREMENTS: Participants were asked their perceptions of the level of harmful chemicals in e-cigarettes versus cigarettes (fewer/about the same/more/do not know), perceived harmfulness of using e-cigarette versus cigarettes (less/about the same/more/do not know) and their current e-cigarette use and use interest. FINDINGS: Approximately 20% of all participants (18.1% of adult smokers, and 21.0% of young adult non-smokers) believed e-cigarettes contain fewer harmful chemicals than cigarettes, while 35.6% of adult smokers and 24.9% of young adult non-smokers responded 'do not know'. Participants more frequently reported 'do not know' to the chemicals item than the harm item. Approximately half (51.0-55.7%) of those who believed e-cigarettes contain fewer harmful chemicals also believed e-cigarettes are less harmful than cigarettes. Both beliefs were associated with higher odds of interest in using e-cigarettes [less harmful belief, odds ratio (OR) = 5.53, 95% confidence interval (CI = 2.93-10.43); fewer chemicals belief, OR = 2.45, 95% CI = 1.40-4.29] and past 30-day e-cigarette use (less harmful belief, OR = 2.53, 95% CI = 1.17-5.44; fewer chemicals belief, OR = 5.09, 95% CI = 2.31-11.19) for adults who smoke, but not young adult non-smokers. CONCLUSIONS: In the United States, most adults who smoke cigarettes and young adult non-smokers do not appear to think that e-cigarettes have fewer harmful chemicals than cigarettes, and many are uncertain about how these levels compare.