E-cigarette use frequency by smoking status among youth in the United States, 2014-2019

Tam, J.

Aims: To report annual 2014-2019 youth estimates of past 30-day e-cigarette use frequency by smoking status in the United States (US). Design: Weighted prevalence estimates of students e-cigarette use using the 2014-2019 National Youth Tobacco Surveys (NYTS). For each year, t-tests for significance were used to compare estimates with those from the preceding year; t-tests were not performed on data for 2019 due to the change in survey format from paper to electronic. Setting: The NYTS is an annual school-based cross-sectional survey of US middle school (MS) and high school (HS) students. Participants: 117,472 students. Measurements: Self-report of past 30 day e-cigarette use based on students smoking status. Smoking status is assessed by asking if students have ever tried smoking, even one or two puffs, with never smokers responding no. Former smokers respond yes but have not smoked at all in the past 30 days. Current smokers used cigarettes at least once in the past 30 days. Frequent e-cigarette use is defined as use on 20 or more days in the past month. Findings: Past 30-day and frequent e-cigarette use increased among never, former, and current smoker youth from 2014-2019. In 2019, a greater proportion of current smokers used e-cigarettes frequently (HS = 46.1%, 95% CI: 39.1, 53.2; MS = 27.4%, 95% CI: 21.1, 33.6) compared to former smokers (HS = 23.2%, 95% CI: 18.1, 28.2; MS = 10.9%, 95% CI: 6.1, 15.7) and never smokers (HS = 3.7%, 95% CI: 3.0, 4.3; MS = 0.7%, 95% CI: 0.4, 0.9). From 2018 to 2019, the total number of youth using e-cigarettes frequently who were never smokers (2018: 180,000; 2019: 490,000) or former smokers (2018: 260,000; 2019: 640,000) surpassed that of current smokers (2018: 420,000; 2019: 460,000). Conclusions: The proportion and number of never smoker youth using e-cigarettes frequently increased greatly since 2014.