title: A Qualitative Approach to Understanding Real-World Electronic Cigarette Use: Implications for Measurement and Regulation.
abstract: BACKGROUND
  An understanding of the real-world use of electronic cigarettes (e-cigarettes) is needed to inform surveillance efforts and future state and federal regulation. This study investigates the behavioral aspects of e-cigarette use.
  
  
  METHODS
  We used qualitative methods to examine salient characteristics of e-cigarette use. The lead investigator (M.C.) conducted in-depth, semistructured individual interviews to explore patterns and behaviors associated with e-cigarette use among a purposive sample of 50 current adult users. Thematic content analysis was used to analyze qualitative data and document themes.
  
  
  RESULTS
  Several important themes emerged. Although most users started with "closed system" products, the majority switched from that type of e-cigarette to "open system" devices. Responses were diverse on preferred flavors, although mixing flavors was a common practice. Many users had difficulty estimating the total amount of e-liquid they used within a given period and described an iterative process in which they experimented with different nicotine levels to determine their preferred concentration. Reported frequency of use and puffing behaviors varied greatly between users and also differed from the way traditional cigarettes are smoked.
  
  
  CONCLUSIONS
  Results from this study have implications for developing appropriate survey metrics for e-cigarette surveillance, the regulation of flavorings, and reporting of e-cigarette product constituents.
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, 400 W. 15th Street, Suite 1050, Austin, TX 78701. E-mail: Maria.R.Cooper@uth.tmc.edu.
authors.forename: Maria
authors.initials: M
authors.lastname: Cooper
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, Austin, Texas.
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Harrell
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, Austin, Texas.
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Perry
mesh_terms: D000328:Adult; D003625:Data Collection; D066300:Electronic Nicotine Delivery Systems / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data* / Q000639:trends*; D005260:Female; D006801:Humans; D008297:Male