Internalizing and externalizing problems on the age of e-cigarette initiation in youth: Findings from the Population Assessment of Tobacco and Health (PATH), 2013-2017.

Previous research has established an association between internalizing and externalizing problems with e-cigarette use in youth. Secondary analysis of Population Assessment of Tobacco and Health youth waves 1-4(2013-2017). Age of initiation of ever e-cigarette use and age of first report of past 30-day e-cigarette use were prospectively estimated among never e-cigarette users(waves 1-3). Weighted interval-censoring multivariable Cox proportional hazard models were fit to assess differences in each e-cigarette outcome among youth with internalizing and externalizing problems, as well as the interaction between internalizing and externalizing problems, while adjusting for covariates. Weighted interval-censoring survival analyses estimated the age of initiation of ever and age of first report of past 30-day e-cigarette use stratified by internalizing and externalizing problems. Among youth never e-cigarette users, those with high internalizing problems and high externalizing problems had increased risk of initiating ever e-cigarette use at earlier ages compared to youth with none/low internalizing and externalizing problems, respectively. Youth with high internalizing problems and high externalizing problems had increased risk of first reporting past 30-day e-cigarette use at earlier ages compared to youth with none/low internalizing problems, respectively. By age 17, 36.3% of youth with high internalizing problems and 38.5% of youth with high externalizing problems initiated ever e-cigarette use. By age 17, 16.8% of youth with high internalizing and 18.7% of youth with high externalizing problems first reported past 30-day e-cigarette use. Youth with internalizing and externalizing problems should be screened for e-cigarette use and provided with proper resources to prevent onset of e-cigarette use.