Patterns of Nicotine and Tobacco Product Use in Youth and Young Adults in the United States, 2011-2015.Introduction
 As cigarette smoking has decreased among youth and young adults (YAs) in the United States, the prevalence of other tobacco and nicotine product use has increased.


 This study identified common past 30-day patterns of tobacco and nicotine product use in youth (grades 6-12) and YAs (aged 18-24).  Using data from the 2011-2015 National Youth Tobacco Survey (NYTS) and corresponding years of the Truth Initiative Young Adult Cohort Study (TIYAC), past 30-day use of the following products was assessed: cigarettes, e-cigarettes, any type of cigar, smokeless tobacco, hookah, and other tobacco products (pipe, bidis, kreteks, dissolvable tobacco, and snus).  A user-generated program in R was used to assess all possible combinations of product-specific and polytobacco use.


 Results
 The top five patterns of past 30-day use in youth were exclusive cigarette use (12.0%), exclusive cigar use (10.3%), exclusive e-cigarette use (10.0%), dual use of cigarettes and cigars (6.1%), and exclusive hookah use (5.2%).  In YAs, the top five patterns were exclusive cigarette use (46.5%), exclusive cigar use (10.0%), dual use of cigarettes and cigars (6.4%), exclusive hookah use (5.9%), and dual use of cigarettes and e-cigarettes (3.9%).


 As noncigarette tobacco and nicotine products become increasingly popular among tobacco users, further research is needed to identify predictors and correlates of specific tobacco use patterns in youth and YAs.  This analysis can inform tobacco prevention efforts focusing on emerging tobacco products such as e-cigarettes and hookah.  Educational and other intervention efforts should focus on the diversity of products and use patterns in these age groups.


 This study uses population-based data to provide new information on the most prevalent patterns of past 30-day nicotine and tobacco use over a 5-year period among youth and young adults.  Study findings demonstrate that youth and young adults report using tobacco and nicotine products in different combinations, with varying popularity over time.  Additionally, by examining young adults as a separate group, this study highlights the unique patterns of use not previously discussed in the adult literature.
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Patterns of Nicotine and Tobacco Product Use in Youth and Young Adults in the United States, 2011-2015.Introduction
 As cigarette smoking has decreased among youth and young adults (YAs) in the United States, the prevalence of other tobacco and nicotine product use has increased.


 This study identified common past 30-day patterns of tobacco and nicotine product use in youth (grades 6-12) and YAs (aged 18-24).  Using data from the 2011-2015 National Youth Tobacco Survey (NYTS) and corresponding years of the Truth Initiative Young Adult Cohort Study (TIYAC), past 30-day use of the following products was assessed: cigarettes, e-cigarettes, any type of cigar, smokeless tobacco, hookah, and other tobacco products (pipe, bidis, kreteks, dissolvable tobacco, and snus).  A user-generated program in R was used to assess all possible combinations of product-specific and polytobacco use.


 The top five patterns of past 30-day use in youth were exclusive cigarette use (12.0%), exclusive cigar use (10.3%), exclusive e-cigarette use (10.0%), dual use of cigarettes and cigars (6.1%), and exclusive hookah use (5.2%).  In YAs, the top five patterns were exclusive cigarette use (46.5%), exclusive cigar use (10.0%), dual use of cigarettes and cigars (6.4%), exclusive hookah use (5.9%), and dual use of cigarettes and e-cigarettes (3.9%).


 Conclusions
 As noncigarette tobacco and nicotine products become increasingly popular among tobacco users, further research is needed to identify predictors and correlates of specific tobacco use patterns in youth and YAs.  This analysis can inform tobacco prevention efforts focusing on emerging tobacco products such as e-cigarettes and hookah.  Educational and other intervention efforts should focus on the diversity of products and use patterns in these age groups.


 Implications
 This study uses population-based data to provide new information on the most prevalent patterns of past 30-day nicotine and tobacco use over a 5-year period among youth and young adults.  Study findings demonstrate that youth and young adults report using tobacco and nicotine products in different combinations, with varying popularity over time.  Additionally, by examining young adults as a separate group, this study highlights the unique patterns of use not previously discussed in the adult literature.
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