A mixed-methods analysis of a do-it-yourself e-cigarette community on Reddit.

INTRODUCTION: Flavored e-cigarette use among US youth remains prevalent, prompting regulatory action by the Food and Drug Administration (FDA). On 2 January 2020, the FDA announced a federal ban on flavored e-cigarettes, which may be circumvented through unregulated do-it-yourself (DIY) methods shared in online communities. Understanding discourse within these communities is essential to understanding unintended policy effects. This study's primary aim was to describe discourse in a DIY e-cigarette subreddit, with a secondary aim of examining how discussions shifted following the 2020 flavor ban. METHODS: We conducted a mixed-methods study of posts from the subreddit r/DIY_eJuice, an online community focused on DIY e-liquid mixing. A total of 5110 posts were extracted between January 2019 and January 2021, with posts before 2 January 2020 defined as the pre-ban period and those after as the post-ban period. From this dataset, we randomly selected 800 posts (17% of the total; 400 pre-ban and 400 post-ban), which were coded by three trained human coders using a systematically developed codebook with 12 thematic categories. Chi-squared tests were applied to compare thematic distributions between periods. RESULTS: DIY mixing methods (76%, n=605) and discussions about flavors (49%, n=390) were the most frequent topics across both periods, despite the flavor ban. Policy-related discussions significantly increased from 3.5% (n=14) pre-ban to 8.3% (n=33) post-ban (p=0.004). Posts related to safety concerns remained infrequent in both pre- and post-ban period. The proportion of beginner users was constant at 22% across both periods (n=90 at pre-ban, and n=88 at post-ban), while discussions by experienced users increased from 35.3% (n=141) to 41.5% (n=166). CONCLUSIONS: Regulatory action on flavored e-cigarettes influenced community discourse, increasing conversations about policy and DIY mixing techniques, but not significantly affecting discussions of safety. Continued surveillance of DIY communities is necessary to inform future public health strategies.