Friends and family matter Most: a trend analysis of increasing e-cigarette use among Irish teenagers and socio-demographic, personal, peer and familial associations

BACKGROUND: E-cigarette ever-use and current-use among teenagers has increased worldwide, including in Ireland. METHODS: We use data from two Irish waves (2015, 2019) of the European School Survey Project on Alcohol and other Drugs (ESPAD) to investigate gender and teenage e-cigarette use (n = 3421 16-year-olds). Using chi-square analyses, we report changes in e-cigarette ever-use, current-use, and associated variables. Using multivariable logistic regression, we analyse the increase in e-cigarette use and socio-demographic, personal, peer and familial associations, focusing on gender differences. RESULTS: E-cigarette ever-use increased from 23% in 2015 to 37% in 2019, and current-use from 10 to 18%. Compared with 2015, the odds in 2019, of becoming both an e-cigarette ever-user and current-user, were significantly higher for girls than boys (ever-use: AOR 2.67 vs 2.04; current-use: AOR 3.11 vs 1.96). Smoking and e-cigarette use are linked but never-smokers who try e-cigarettes rose significantly from 33 to 67% and those using e-cigarettes to quit smoking decreased significantly from 17 to 3%. Almost two-thirds of respondents (66%) in 2019 said that their reason for trying e-cigarettes was “out of curiosity”. Peer smoking is significantly associated with likelihood of e-cigarette ever-use (AOR 6.52) and current-use (AOR 5.45). If “Most/All friends smoke”, odds were significantly higher for boys than for girls (ever-use AOR 7.07 vs 6.23; current-use AOR 5.90 vs 5.31). Less parental monitoring is significantly associated with greater e-cigarette ever-use (AOR 3.96) and current-use (4.48), and having parents who usually don’t know where their child is on Saturday nights was also associated with significantly higher odds for boys than for girls (ever-use AOR 5.42 vs 3.33; current-use AOR 5.50 vs 3.50). CONCLUSION: Respondents had significantly higher odds of being e-cigarette ever- and current-users in 2019 compared with 2015. Use is higher among boys but girls are increasingly at risk. Two-thirds had never smoked cigarettes at first e-cigarette use; two-thirds used out of curiosity but few (3%) for smoking cessation. The most prominent risk factors for e-cigarette use were peer- and parent-related, especially so for boys. Interventions that take account of friend and family influences may provide mechanisms for preventing an increasing risk of nicotine addiction. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-12113-9.