Temporal Trends in Smokeless Tobacco Use Among US Middle and High School Students, 2000-2011

To the Editor: Tobacco use remains the leading preventable cause of death and disease in the United States.¹ Declines in smoking among youths were observed from the late 1990s, particularly after the Master Settlement Agreement in 1998.² However, limited information exists on trends in smokeless tobacco use among US youths.

One study³ showed a decreasing trend in smokeless tobacco use during 1986 through 2003 before the increased availability of flavored products that may appeal to youths. This study analyzed recent trends in prevalence of smokeless tobacco use among youths using the 2000-2011 National Youth Tobacco Survey (NYTS).

The NYTS is a repeated, biennial national cross-sectional survey of US middle and high school students. Samples during 2000 through 2011 ranged from 35 828 students in 324 schools in 2000 to 18 866 students in 178 schools in 2011. Overall response rates ranged from 72.7% (in 2000) to 84.1% (in 2011).

Parental permission was obtained for each student, and participation was voluntary and anonymous. The initial NYTS study protocols were reviewed and approved by the US Centers for Disease Control and Prevention's institutional review board. The current trend analysis was performed on publicly available deidentified data and was exempt from institutional review board approval as nonhuman research.

Current smokeless tobacco use was defined as use of snuff, chewing, or dipping tobacco for 1 or more days within the past 30 days. Because NYTS data are based on a sample of the population, they are subject to sampling error. Hence, estimates with relative standard errors of 40% or greater were considered statistically unreliable and not reported.

Unadjusted average annual percentage changes (AAPC) during 2000 through 2011 were calculated using Joinpoint analysis. Binary logistic regression was used to assess for linear trends, controlling for age, school level, race/ethnicity, and sex (P < .05). Data were weighted and analyzed with Stata version 12 (StataCorp) and Joinpoint version 4.0.1 (National Cancer Institute) software.

No significant change in overall smokeless tobacco prevalence occurred between 2000 (5.3%; 95% CI, 4.5% to 6.1%) and 2011 (5.2%; 95% CI, 4.2% to 6.1%) (Table). Downward trends were observed in the age groups of 9 to 11 years (AAPC, −4.6 [95% CI, −11.9 to 3.4]; P = .007 for linear trend) and 12 to 14 years (AAPC, −3.4 [95% CI, −5.3 to −1.4]; P = .02 for linear trend).

Conversely, prevalence increased in the age group of 15 to 17 years (AAPC, 0.9 [95% CI, −2.8 to 4.7]; P = .01 for linear trend). During 2000 through 2011, prevalence declined among middle school students (AAPC, −4.1 [95% CI, −5.7 to −2.4]; P = .02 for linear trend). No significant changes were noted among high school students, or by race/ethnicity or sex.

The prevalence of smokeless tobacco use among US youths did not change between 2000 and 2011 and remained generally low. However, subgroup differences were observed. The use of modified traditional smokeless tobacco products, such as moist snuff, coupled with lower taxes on smokeless tobacco products (vs cigarettes) may have contributed to the stable prevalence of smokeless tobacco (vs the declining trend for cigarettes).

In addition, use of flavors is not currently prohibited for smokeless tobacco products, unlike with cigarettes.⁴ The significant declines among respondents aged 14 years or younger and those in middle school may be attributable to the proliferation of bans and restrictions in many states on remote (mail order or Internet) sales of tobacco products coupled with the recent implementation of federal legislation enforcing age verification at points of purchase.⁵

Despite these developments, significant increases were observed among those aged 15 to 17 years, whereas no significant changes were seen among respondents aged 18 years or older, suggesting that current access laws are not completely effective in preventing tobacco access among older adolescents. Furthermore, the promotion of smokeless tobacco use as an alternative to smoking is more likely directed at smokers, who are more likely to be older than younger adolescents.⁶

This study is subject to limitations. First, insufficient data existed on smokeless tobacco type, and the analysis did not include newer smokeless tobacco products such as snus and dissolvable tobacco products, which may have resulted in an underestimation of smokeless tobacco prevalence. In addition, recall bias may have resulted in an underreporting of tobacco use. Nonetheless, these findings emphasize the need for evidence-based interventions to reduce smokeless tobacco use among youths.

Author Contributions: Dr Agaku had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Agaku, Vardavas, Connolly.

Acquisition of data: Agaku, Connolly.

Analysis and interpretation of data: Agaku, Vardavas, Ayo-Yusuf, Alpert, Connolly.

Drafting of the manuscript: Agaku, Vardavas.

Critical revision of the manuscript for important intellectual content: Agaku, Vardavas, Ayo-Yusuf, Alpert, Connolly.

Statistical analysis: Agaku, Vardavas, Ayo-Yusuf.

Obtained funding: Connolly.

Study supervision: Vardavas.

Funding/Support: National Cancer Institute grants 3R01 CA125224-03s1rev++ and 2R01 CA087477-09A2 funded the research for this study.

Role of the Sponsor: The National Cancer Institute had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.

This article was corrected for errors on May 14, 2013.