An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Pérez A, Bluestein M, Chen B, Perry CL, Harrell MB.Pérez A, et al. Among authors: chen b.J Biom Biostat. 2020;11(4):https://www.hilarispublisher.com/open-access/prospectively-estimating-the-age-of-initiation-of-ecigarettes-among-us-youth-findings-from-the-population-assessment-of-.pdf. Epub 2020 May 19.J Biom Biostat. 2020.PMID: 33552669Free PMC article.