Relationship between e-cigarette point of sale recall and e-cigarette use in secondary school children: a cross-sectional study.

BACKGROUND: There has been a rapid increase in the retail availability of e-cigarettes in the UK and elsewhere. It is known that exposure to cigarette point-of-sale (POS) displays influences smoking behaviour and intentions in young people. However, there is as yet no evidence regarding the relationship between e-cigarette POS display exposure and e-cigarette use in young people. METHODS: This cross sectional survey was conducted in four high schools in Scotland. A response rate of 87 % and a total sample of 3808 was achieved. Analysis was by logistic regression on e-cigarette outcomes with standard errors adjusted for clustering within schools. The logistic regression models were adjusted for recall of other e-cigarette adverts, smoking status, and demographic variables. Multiple chained imputation was employed to assess the consistency of the findings across different methods of handling missing data. RESULTS: Adolescents who recalled seeing e-cigarettes in small shops were more likely to have tried an e-cigarette (OR 1.92 99 % CI 1.61 to 2.29). Adolescents who recalled seeing e-cigarettes for sale in small shops (OR 1.80 99 % CI 1.08 to 2.99) or supermarkets (OR 1.70 99 % CI 1.22 to 2.36) were more likely to intend to try them in the next 6 months. CONCLUSIONS: This study has found a cross-sectional association between self-reported recall of e-cigarette POS displays and use of, and intention to use, e-cigarettes. The magnitude of this association is comparable to that between tobacco point of sale recall and intention to use traditional cigarettes in the same sample. Further longitudinal data is required to confirm a causal relationship between e-cigarette point of sale exposure and their use and future use by young people.