Demographic Characteristics, Cigarette Smoking, and e-Cigarette Use Among US Adults

1Understanding how electronic cigarettes (e-cigarettes) are used by current, former, and never cigarette smokers may inform public health actions and tobacco regulations. Therefore, we examined the distribution of e-cigarette use, also called vaping, in the 2018-2019 Tobacco Use Supplement to the Current Population Survey, the largest nationally representative tobacco use survey of US adults.

2This cross-sectional study was determined to be exempt from review by an institutional review board at the National Institutes of Health because it was not human subjects research and used deidentified public use data. Informed consent was obtained prior to interviews by the US Census Bureau, which conducted the field work. In this study, adults aged 18 years and older were interviewed by phone (two-thirds of respondents) or in-home (one-third of respondents) once between July 2018 and May 2019 using probability-based multistage sampling. Among 137 471 self-respondents (self-response rate = 57.6%), we examined current e-cigarette use by demographic characteristics and cigarette smoking status. We also assessed whether former and current cigarette smokers who vape reported using e-cigarettes to help them quit smoking. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

3Weighted frequencies and proportions for statistical analysis were estimated with SAS-Callable SUDAAN (SAS version 9.4 [SAS Institute]; SUDAAN version 11.0.3 [RTI International]) using self-response survey weights. Data analysis was performed from October 2019 to July 2020.

4The 2018-2019 Tobacco Use Supplement to the Current Population Survey was weighted to reflect the demographic characteristics of the US adult population. Our analytic sample included an unweighted total of 135 211 individuals with information on both cigarette and e-cigarette use (73 853 women [weighted percentage, 51.9%], weighted mean [SE] age 47.5 years [0.0]), of which 16 570 were current smokers (11.4% [95% CI, 11.2%-11.6%]), 29 189 were former smokers (18.2% [95% CI, 18.0%-18.5%]), and 90 906 were never cigarette smokers (70.3% [95% CI, 70.0%-70.7%]).

5Overall, we estimate that more than 5.66 million adults in the US population reported current vaping (2.3% [95% CI, 2.2%-2.4%]). Among e-cigarette users, more than 2.21 million were current cigarette smokers (39.1% [95% CI, 36.8%-41.4%]), more than 2.14 million were former smokers (37.9% [95% CI: 35.6%-40.1%]), and more than 1.30 million were never smokers (23.1% [95% CI, 20.8%-25.4%]) (Table 1).

6The prevalence of vaping was higher among men (2.8%; 95% CI, 2.7%-3.0%) and among non-Hispanic White (2.8% [95% CI, 2.6%-2.9%]), American Indian/Alaskan Native (4.2% [95% CI, 2.8%-6.4%]), and multiracial (4.5% [95% CI, 3.3%-6.2%]) individuals. There was higher prevalence with increasing education level (less than high school: 2.2% [95% CI, 1.8%-2.6%]; high school degree: 3.0% [95% CI, 2.7%-3.2%]; and some college: 3.1% [95% CI, 2.8%-3.3%]), except for individuals with a college degree (1.2% [95% CI, 1.1%-1.4%]), who had the lowest prevalence. Across all categories of sex, race/ethnicity, and education, the majority of vapers were current or former smokers. There were, however, differences by age. Among never smokers who vaped, 63.4% (95% CI, 58.2%-68.7%) were between 18 and 24 years old, and 23.8% (95% CI, 19.6%-28.1%) were between 25 and 34 years old. In contrast, e-cigarette users who were current or former smokers tended to be older (Table 1).

7Among current dual users of cigarettes and e-cigarettes, 69.3% (95% CI, 65.7%-72.7%) reported using e-cigarettes to try to quit smoking. However, among former smokers who currently vape, 80.7% (95% CI, 77.4%-83.5%) reported that they had used e-cigarettes to help them quit smoking (Table 2).

8We estimate a vaping prevalence of 2.3% among US adults. An estimated 39.1% of e-cigarette users were current smokers and 37.9% were former smokers. A majority of both groups reported using or having used e-cigarettes to help them quit cigarette smoking. Whether vaping actually helps smokers quit is unclear, however, and cannot be evaluated using cross-sectional data. Longitudinal studies and trials are needed to answer this important question and to determine the long-term health effects of dual use, which was the most common pattern of use reported. The large number of former smokers who currently vape is additionally worrisome, given recent reports that former smokers who vape are more likely to experience a smoking relapse.

9Additionally, 23.1% of e-cigarette users reported never smoking, and most were younger than 35 years. In addition to the potential health effects of vaping, the young age of many users is concerning, particularly as nicotine is highly addictive and can negatively affect brain development, which continues until age 25 years.

10Limitations of this study include a cross-sectional design and self-reported data. Strengths of these analyses include recency of the data and a large nationally representative sample, which makes the findings generalizable.

11e-Cigarettes are now used by large numbers of never, former, and current cigarette smokers in the US population. Given the rapidly changing e-cigarette marketplace and recent increases in the prevalence of use among youth and young adults, continued surveillance is needed.