Initiation of Electronic Cigarette Use by Age Among Youth in the U.S

Introduction: The rapid increase in electronic cigarette (e-cigarette) smoking among U.S. youth requires data regarding the age pattern of initiation risk for effective tobacco use prevention. Methods: Data from the 2014 National Youth Tobacco Survey (N=20,680, aged 11-19 years, 50.6% male) were analyzed using survival analysis in 2016 to quantify the likelihood of e-cigarette use initiation by age, overall and by gender and racial/ethnic groups. Results: The estimated mean age of e-cigarette initiation was 17.50 (95% CI=17.47, 17.52) years. The estimated hazards of e-cigarette use initiation were 0 up to age 6 years, increased slowly from age 7 to 11 years, and continued with an accelerated increase up to age 17 years before it slowed down. There were significant gender (male 4 female) and racial/ethnicity (from high to low: multiracial, white, Hispanic, African, and Asian) differences in the age pattern. Conclusions: E-cigarette smoking is initiated as young as age 7 years. Different from conventional cigarette smoking with peak initiation risk at age 14-15 years, the likelihood of initiating e-cigarette smoking continues to increase up to age 18 years. The unique age pattern and significant gender and racial/ethnic differences provide useful data to support further research to strengthen tobacco use prevention in the U.S. (C) 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.