Longitudinal impact of perceived harm and addiction on e-cigarette initiation among tobacco-naïve youth: Population Assessment of Tobacco and Health study (Waves 1-5).

Objectives: This study investigates the effect of e-cigarette-related harm and addiction perceptions on e-cigarette initiation among US tobacco-naïve adolescents.

Study Design: This is a longitudinal study.

Methods: Using data from five waves (2013-2019) of the Population Assessment of Tobacco and Health Study, we created a longitudinal data set for 2775 youth aged 12-17 years who had no prior use of tobacco products at Wave 1. E-cigarette initiation was defined as transitioning from non-use at Wave 1 to ever use in subsequent waves. Kaplan-Meier survival and Cox proportional hazard regression models were used to assess the impact of harm and addiction perceptions on e-cigarette initiation.

Results: Our analytic sample comprised 63.1% of youth who had never used tobacco products at Wave 1 and consequently initiated e-cigarette use in subsequent waves. Over time, fewer individuals perceived e-cigarettes as harmless (14.1%-2.1%), whereas more perceived them as likely to cause addiction (53.7%-76.6%). Compared with perceiving e-cigarettes as a lot of harm, those perceiving some harm (adjusted hazard ratio [aHR] = 1.30, 95% confidence interval [CI]: 1.12-1.52), little harm (aHR = 1.42, 95% CI: 1.20-1.68), or no harm (aHR = 2.09, 95% CI: 1.64-2.65) were more likely to initiate e-cigarette use. Demographic factors for initiation included being Black or Hispanic ethnicity (vs White), younger age (12-14 vs15-17 years), and receiving over $20 per week (vs $0) in pocket money, with P-values <0.05. However, in adjusted results, addiction perceptions did not significantly impact e-cigarette initiation (P-values >0.05).

Conclusions: Among youth without prior tobacco/nicotine use, perceiving e-cigarettes as having low harm significantly predicted initiation over time. Effective prevention strategies, including targeted risk communication interventions, are essential for discouraging e-cigarette use among youth.