title: Trends in Multiple Tobacco Product Use, Among High School Students.
abstract: OBJECTIVE
  The purpose of this study was to identify trends of tobacco use, among all students and current tobacco users, in a nationally representative sample of high school students from 1999 to 2013.
  
  
  METHODS
  Trends in individual and concurrent use of cigarettes, cigars, and smokeless tobacco (SLT) products were tested using 8 repeated cross-sections of the YRBS between 1999 and 2013. Tests for effect modification of race/ethnicity and sex were conducted for each trend.
  
  
  RESULTS
  Among all students, there were significant non-linear changes detected for the concurrent use of all 3 products, and the dual use of cigarettes and cigars. Girls significantly increased their use of SLT. Among users, significant changes were detected for each individual product and all combinations. Female users significantly increased their concurrent use of cigarettes and cigars and concurrent use of cigarettes and SLT. Male users significantly decreased their use of cigarettes and cigars.
  
  
  CONCLUSIONS
  While the decrease in the youth prevalence of cigarette use is a public health success, there is concern about the increase in non-cigarette products, among tobacco users. These changes further drive increases in the concurrent use of tobacco products, adding to the potential health burden.
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, Department of Health Promotion and Behavioral Sciences, Austin, TX.
authors.forename: MeLisa R
authors.initials: MR
authors.lastname: Creamer
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, Department of Health Promotion and Behavioral Sciences, Austin, TX.
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Perry
authors.affiliation: University of Texas School of Public Health, Austin Regional Campus, Department of Epidemiology, Human Genetics, and Environmental Sciences, Austin, TX.
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Harrell
authors.affiliation: University of Texas School of Public Health, Department of Health Promotion and Behavioral Sciences, Houston, TX.
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Diamond
keywords: adolescents; multiple product use