Day-level associations of nicotine and cannabis vaping and co-vaping with sleep duration and quality among young adults: A smartphone-based daily diary study.

Over half of daily assessments among young adult vapers reported inadequate sleep duration.

• Of 2,147 daily assessments, 51.7% reported inadequate sleep (defined as less than 7 hours)
• Mean sleep quality was 6.1 ± 2.1 on a 0–10 scale
• Sample consisted of 111 California young adults aged 18–29 (mean age 23.9 ± 3.0)
• Participants vaped nicotine and/or cannabis ≥20 days per month and completed 30 consecutive days of smartphone-based surveys

Nicotine-only vaping was the most frequently reported daily vaping pattern among participants.

• Nicotine-only vaping was reported on 42.5% of days
• Same-day co-vaping (both nicotine and cannabis) occurred on 32.1% of days
• Non-vaping days accounted for 16.1% of assessments
• Cannabis-only vaping was reported on 9.3% of days

Nicotine-only vaping days were associated with greater odds of inadequate sleep compared to non-vaping days.

• OR = 1.40 (95% CI: 1.01–1.94) for inadequate sleep on nicotine-only vaping days versus non-vaping days
• Models were generalized mixed-effects models adjusting for other substance use and baseline covariates
• Sleep duration was defined as inadequate if less than 7 hours and adequate if 7 or more hours

Nicotine-only vaping days were associated with nearly twice the odds of inadequate sleep compared to cannabis-only vaping days.

• OR = 1.93 (95% CI: 1.31–2.85) for inadequate sleep on nicotine-only vaping days versus cannabis-only vaping days
• This was the largest significant odds ratio observed across vaping pattern comparisons for sleep duration

Same-day co-vaping (nicotine and cannabis together) was associated with greater odds of inadequate sleep compared to cannabis-only vaping.

• OR = 1.50 (95% CI: 1.01–2.23) for inadequate sleep on co-vaping days versus cannabis-only vaping days
• Co-vaping occurred on 32.1% of all daily assessments, making it the second most common vaping pattern

Cannabis vaping was not associated with improved sleep quality compared to non-vaping.

• Associations between sleep quality and daily vaping patterns were not statistically significant for any comparison
• This finding contradicts a common reason young adults report using cannabis, namely to aid sleep
• Sleep quality was self-reported on a scale from 0 (terrible) to 10 (excellent)

Cannabis-only vaping days were associated with lower odds of inadequate sleep duration compared to both nicotine-only and co-vaping days, but not significantly better than non-vaping days.

• Cannabis-only vaping was not shown to produce significantly better sleep duration than non-vaping in the models
• However, nicotine-only vaping (OR=1.93) and co-vaping (OR=1.50) both showed significantly worse sleep duration compared to cannabis-only vaping
• These comparisons suggest cannabis-only vaping occupies an intermediate position relative to nicotine-containing patterns

The study used a smartphone-based daily diary methodology with a demographically diverse young adult sample.

• Sample was 64% female and 31.5% non-Hispanic White, recruited in California from 2023 to 2024
• Participants completed 30 consecutive days of surveys, yielding 2,147 daily assessments across 111 participants
• Generalized mixed-effects models accounted for the nested structure of daily observations within participants
• Models adjusted for other substance use and baseline covariates