Document Type



Doctor of Philosophy (PhD)


Public Health

First Advisor's Name

Wasim Maziak

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Miguel Angel Cano

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Tan Li

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Matthew T. Sutherland

Fourth Advisor's Committee Title

Committee Member


ENDS, Electronic cigarette, E-cigarette, Young people, Harm perception, Health warning label

Date of Defense



This dissertation 1) assessed the influence of electronic nicotine delivery systems (ENDS) harm perception on ENDS initiation over time among US youth and young adults; 2) tracked the changes in harm perception of ENDS use and examined their predictors among US youth; 3) conducted a pilot study to address the effectiveness of graphic health warning labels (GHWLs) on important outcomes among US young adult ENDS users. Data from 2013-2018 of the Population Assessment of Tobacco and Health (PATH) study were used for aims 1 & 2. Primary data with 26 participants that were collected from university campus during the year 2019 were used for aim 3.

In the first study, 17.1% of adolescents and 25.5% of young adults who never used ENDS at Wave 1, initiated ENDS use in subsequent waves. Perceiving ENDS as lower relative harm predicted ENDS initiation among adolescents (HR=2.33; 95%CI: 1.98-2.74) and young adults (HR=2.01; 95%CI: 1.72-2.36). Perceiving ENDS as lower absolute harm (HR=2.22; 95%CI: 1.87-2.63) predicted ENDS initiation among adolescents.

In the second study, adolescents who perceived ENDS as lower relative and absolute harm significantly decreased between Wave 1 and Wave 4 (P’s

The final study evaluated the effect of placing GHWLs on the ENDS devices on users’ experience. Compared to the control sessions, using JUUL with GHWLs on the device was significantly associated with reduced positive experience such as pleasure, and product liking (P’s

This study highlighted the importance of harm perception for ENDS initiation and the central role of risk communication strategies that need to target young people at risk of unwarranted ENDS use. Additionally, this proposal emphasized the demand for more effective tobacco regulatory policies to deter the ENDS epidemic among young people.





Previously Published In

Li, W., Osibogun, O., Li, T., Sutherland, M. T., Maziak, W., 2022. Changes in Harm Perception of ENDS and their Predictors among US Adolescents: Findings from the Population Assessment of Tobacco and Health (PATH) Study, 2013-2018. Prev Med.

Li, W., Vargas-Rivera, M., Ebrahimi Kalan, M., Ben Taleb, Z., Asfar, T., Osibogun, O., Noar, S. M., Maziak, W., 2021. The Effect of Graphic Health Warning Labels Placed on the ENDS Device on Young Adult Users' Experience, Exposure and Intention to Use: A Pilot Study. Health Commun. 1-8.

Included in

Epidemiology Commons



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