E-cigarette use and adverse respiratory symptoms among adolescents and Young adults in the United States.

E-cigarette use among adolescents and young adults has been associated with adverse respiratory symptoms, including symptoms of asthma and bronchitis. This investigation examined whether such associations differ by primary type of e-cigarette device used. This cross-sectional study included data from four study populations in California and Connecticut, United States, ages 13-21 years (N = 10,483), who self-reported their tobacco use behaviors and health status from 2018 to 2020. Adverse respiratory symptoms were grouped as bronchitis, asthma exacerbation, and shortness of breath. Associations with e-cigarette use were examined by frequency of e-cigarette use (regardless of device type) and most-frequently use device type in the past 30 days (pod, pen/tank, disposable, or mod). Multivariable modeling accounted for demographic variables and use of other tobacco and cannabis. Results were pooled at the study level via random-effects meta-analysis. Across the four studies, e-cigarette use >5 days/month versus never use was associated with bronchitic symptoms (summary odds ratio, sOR: 1.56; 95% confidence interval, CI: 1.37, 1.77) and shortness of breath (sOR: 1.68; 95% CI: 1.35, 2.08) but not statistically significantly with asthma exacerbations (sOR: 1.36; 95% CI; 0.95, 1.95). Among past 30-day e-cigarette users, associations with respiratory symptoms did not differ by device type. In these populations, e-cigarette use was positively associated with symptoms of bronchitis and shortness of breath, but adjusted odds of symptoms did not differ meaningfully by device type. These findings suggest that risk of these respiratory outcomes is elevated among more frequent e-cigarette users regardless of device type used.