Dependence on nicotine in US high school students in the context of changing patterns of tobacco product use.

BACKGROUND AND AIM

There have been substantial recent changes in youth tobacco product use in the United States-including, notably, a rapid increase in use of e-cigarettes. It is not known whether, and if so how far, these changes are reflected in levels of nicotine dependence. This study used data from a large, nationally representative sample of US adolescents to (i) estimate the annual prevalence of nicotine dependence in relation to current use of tobacco products, (ii) describe trends in dependence over time and (iii) evaluate whether the increase in youth use of tobacco products has been paralleled by a similar increase in the population burden of nicotine dependence.

DESIGN

Secondary analysis of National Youth Tobacco Surveys conducted annually, 2012-19.

SETTING

United States.

PARTICIPANTS

A total of 86 902 high school students.

MEASUREMENTS

Prevalence of (i) strong cravings to use tobacco in the past 30 days and (ii) wanting to use nicotine products within 30 minutes of waking, in relation to type of product used (cigarettes, other combustible tobacco, smokeless tobacco, e-cigarettes).

FINDINGS

Between 2012 and 2019 there was a marked decline in past 30-day cigarette smoking and a surge in use of e-cigarettes. Different products were associated with differing levels of nicotine dependence, with cigarettes characterized by highest dependence (strong craving 42.3%; wanting to use within 30 minutes 16.8% among exclusive users in 2019) and e-cigarettes in otherwise tobacco-naive students by low dependence (16.1 and 8.8% respectively in 2019). The overall 33.8% increase in population use of nicotine products between 2012 and 2019 (from 23.2 to 31.2%) was not accompanied by an equivalent increase in overall population burden of dependence {percentage reporting craving 10.9% [95% confidence interval (CI) = 9.8-12.2%] in 2012 and 9.5% (95% CI = 7.5-12.0%) in 2019; wanting to use within 30 minutes 4.7% (95% CI = 4.0-5.5%) in 2012, 5.4% (95% CI = 4.0-7.2%) in 2019}.

CONCLUSIONS

Among US high school students, increases in the prevalence of nicotine product use from 2012 to 2019 do not appear to have been accompanied by a similar increase in the population burden of nicotine dependence. This may be at least partly attributable to a shift in the most common product of choice from cigarettes (on which users are most dependent) to e-cigarettes (on which users are least dependent).