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.

Aims and 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 = 8231).

Results: Perceiving e-cigarettes as less harmful than cigarettes was associated with higher odds of complete switching from cigarettes to e-cigarettes (adjusted odds ratio [aOR] 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 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, why their effects differ by age, and what factors influence YAs' tobacco use behaviors.