Real-time antecedents of young adults’ vaping and co-vaping of nicotine and cannabis (Preprint)

BACKGROUND Nicotine and cannabis vaping are common among young adults, potentially leading to adverse health consequences. Identifying real-time antecedents of vaping events may provide insights into intervention targets pertinent to these behaviors. OBJECTIVE This study aimed to examine real-time antecedents of nicotine and cannabis vaping and same-moment co-vaping among young adults. METHODS We collected ecological momentary assessments (EMAs) via smartphone app among California young adults (ages 18-29) in 2023-2024. Participants completed four random prompts each day for 30 days. Outcomes were defined as whether participants reported being about to vape nicotine, cannabis, or both substances (same-occasion co-vaping) in a given EMA. We used mixed-effects logistic regression models to examine real-time antecedents of each outcome. RESULTS Overall, 113 participants (mean age 23.8 years, 63% female) completed 9,001 EMAs. Similar antecedents of all three vaping outcomes were craving and using alcohol. Increased cravings for a given substance were associated with a higher likelihood of vaping that substance or co-vaping. Craving for cannabis vaping was associated with lower odds of reporting nicotine vaping. Feeling happier was associated with higher odds of reporting co-vaping while feeling more stressed was associated with lower odds of vaping nicotine or cannabis. Seeing tobacco advertisements was associated with higher odds of vaping nicotine and co-vaping. Cannabis vaping and co-vaping were more likely to occur in the afternoon and nighttime than in the morning. CONCLUSIONS We found similar antecedents (craving, alcohol use) and unique antecedents (mood, advertising exposure, and time of day) for nicotine vaping, cannabis vaping, and same-occasion co-vaping, suggesting targets for future vaping cessation interventions.