Study protocol for comparing the subjective effects and nicotine delivery associated with the use of the EU and the US JUUL pod vaping device in UK smokers

Introduction: Pod Vaping Devices (PVD) such as JUUL have become extremely popular in the US and their popularity is growing in the UK. A key difference between the US and the UK is the nicotine concentration which is typically 59mg/mL in the US but capped at 20mg/mL in the UK and EU. This may limit their ability to deliver satisfactory nicotine levels and promote smoking cessation especially for highly nicotine dependent smokers. The primary aim is to compare the EU-TPD compliant JUUL (18mg/mL nicotine concentration) with the US (non-TPD compliant) JUUL (59mg/mL) on daily smokers’ subjective experiences, craving relief and blood nicotine levels. Methods: Double-blind, counter-balanced within-participants design with 2 conditions: EU vs. US JUUL. Twenty UK smokers will vape ad libitum for 60 mins on 2 separate occasions. 2X5 ANOVAs will be used to compare conditions across time-points for nicotine boost (measured at baseline, 5, 15, 30 and 60 mins), craving and withdrawal symptoms (baseline, 10 and 60 mins) and subjective effects (10 and 60 mins). Within-samples t-test will be used to compare estimated volume of liquid consumed across conditions. Inductive thematic analysis will be used to analyse qualitative data to explore usage patterns, changes in smoking, and experiences of EU JUUL use outside the laboratory over 2-weeks.