Investigating gateway effects using the PATH study

Area of Science:

• Public Health
• Tobacco Control
• Adolescent Health

Background:

• Previous meta-analysis indicated e-cigarette use predicts future cigarette smoking initiation in youth.
• The
• gateway effect
• hypothesis suggests e-cigarette use leads to traditional smoking.
• Limited consideration of confounding factors in prior studies necessitates further investigation.

Purpose of the Study:

• To investigate the potential for confounding in the association between e-cigarette use and subsequent cigarette smoking initiation.
• To re-evaluate the
• gateway effect
• using a more comprehensive adjustment for confounders.
• To utilize data from the Population Assessment of Tobacco and Health (PATH) study, Waves 1 and 2.

Main Methods:

• Propensity score analysis was used to adjust for baseline confounders in Wave 1 never cigarette smokers.
• Sensitivity analyses included adjustment for other tobacco product use and residual confounding.
• Analyses examined Wave 1 e-cigarette use predicting Wave 2 cigarette smoking initiation.

Main Results:

• Adjustment for propensity scores significantly reduced the odds ratio for e-cigarette use predicting smoking initiation.
• Further adjustment for other tobacco products further diminished the observed association.
• Sensitivity analyses confirmed that confounding accounted for the majority of the apparent gateway effect.

Conclusions:

• Confounding is a substantial contributor to the observed association between adolescent e-cigarette use and subsequent cigarette smoking.
• The
• gateway effect
• is largely explained by unmeasured or inadequately measured confounding variables.
• Further research with larger sample sizes and longitudinal data is recommended to clarify residual associations.