title: Patterns of Electronic Cigarette Use Among Adults in the United States.
abstract: BACKGROUND
  Amid increasing rates of electronic cigarette (e-cigarette) use in the United States, there is an urgent need to monitor patterns of use at the population level in order to inform practice, policy and regulation. This article examines how patterns of e-cigarette use among adults differ between users and nonusers of cigarettes using the most current national data.
  
  
  METHODS
  We analyzed data from the 2014 National Health Interview Survey. We estimated prevalence of ever, current, and daily e-cigarette use and examined how use patterns differed by demographic subgroups and measures of cigarette smoking status that accounted for the recent availability of e-cigarettes in the US marketplace.
  
  
  RESULTS
  Current e-cigarette use is extremely low among never cigarette smokers (0.4%) and former smokers who quit cigarettes 4 or more years ago (0.8%). Although e-cigarette experimentation is most common among current cigarette smokers and young adults, daily use is highest among former smokers who quit in the past year (13.0%) and older adults. Compared to daily cigarette smokers, recently quit smokers were more than four times as likely to be daily users of e-cigarettes (AOR: 4.33 [95% CI: 3.08-6.09]).
  
  
  CONCLUSIONS
  Extremely low e-cigarette use among never-smokers and longer term former smokers suggest that e-cigarettes neither promote widespread initiation nor relapse among adults. Recognition of the heterogeneity of smokers, including the time since quitting, is critical to draw accurate conclusions about patterns of e-cigarette use at the population level and its potential for public health benefit or harm.
  
  
  CONCLUSIONS
  Data from 2014 National Health Interview Survey indicate that e-cigarettes have not been attracting adult non-smokers or promoting relapse in longer term former smokers. Moreover, the data are suggestive that some recent quitters may have done so with the assistance of e-cigarettes. Creating measures of smoking status that treat former smokers as a homogenous group is insufficient to assess the epidemiology of e-cigarette use and the potential impact on public health.
authors.affiliation: Center for Tobacco Studies, Rutgers School of Public Health, New Brunswick, NJ; Rutgers Cancer Institute of New Jersey, New Brunswick, NJ; delnevo@rutgers.edu.
authors.forename: Cristine D
authors.initials: CD
authors.lastname: Delnevo
authors.affiliation: Center for Tobacco Studies, Rutgers School of Public Health, New Brunswick, NJ;
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Giovenco
authors.affiliation: Rutgers Cancer Institute of New Jersey, New Brunswick, NJ; Department of Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ;
authors.forename: Michael B
authors.initials: MB
authors.lastname: Steinberg
authors.affiliation: The Schroeder Institute for Tobacco Research and Policy Studies at Truth Initiative, Washington, DC; Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Villanti
authors.affiliation: The Schroeder Institute for Tobacco Research and Policy Studies at Truth Initiative, Washington, DC; Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Pearson
authors.affiliation: The Schroeder Institute for Tobacco Research and Policy Studies at Truth Initiative, Washington, DC; Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Niaura
authors.affiliation: The Schroeder Institute for Tobacco Research and Policy Studies at Truth Initiative, Washington, DC; Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC.
authors.forename: David B
authors.initials: DB
authors.lastname: Abrams
mesh_terms: D066300:Electronic Nicotine Delivery Systems / Q000706:statistics & numerical data; D006801:Humans; D012907:Smoking / Q000628:therapy*; D016540:Smoking Cessation / Q000379:methods / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology