Respiratory symptoms among e-cigarette users without an established smoking history in the VERITAS cohort

Prior research on e-cigarettes' health impacts is inconclusive due to confounding by previous tobacco smoking. Studies of e-cigarette use among people without an established smoking history are informative for this question. A cross-sectional survey was administered across six geopolitical world regions to adults aged 18+ without a history of established cigarette smoking or regular use of other nicotine/tobacco products. Two cohorts were defined based on e-cigarette use: "Vapers Cohort" (N = 491) who used e-cigarettes in the past 7 days and "Control Cohort" (N = 247) who never regularly used e-cigarettes. Frequency of respiratory symptoms (Respiratory Symptom Evaluation Score (RSES)) were compared between cohorts, adjusting for sociodemographics. Tobacco use history and patterns of e-cigarette use was also examined. Respiratory symptoms were rare among both the Vapers and Control Cohorts: 83.3% and 88.4%, respectively, reported "rarely" or "never" experiencing all five RSES items (p = 0.125). The Vapers (vs. Control) Cohort reported modestly more frequent respiratory symptoms (adjusted mean RSES 1.61 vs. 1.43, respectively, p < 0.001); however, this difference (0.18) did not reach the threshold of clinical relevance (0.57). The Vapers (vs. Control) Cohort more often reported former cigarette experimentation (30.8% vs. 12.1%) and former infrequent use of other nicotine/tobacco products (18.1% vs. 5.8%). The Vapers Cohort most often used disposable devices (63.7%) and multiple flavors (approximately 70-80% across primary device type). In this cohort of adults without a history of established combustible tobacco use, e-cigarette use was statistically linked to more frequent respiratory symptoms, though not in a clinically meaningful way. The cross-sectional design of this study cannot establish causality between e-cigarette use and respiratory symptoms.