Adverse symptoms users attribute to e-cigarettes: Results from a national survey of US adults.

Background: Little is known about the prevalence of adverse symptoms electronic cigarette (e-cigarette) users report experiencing.

Methods: Between August 2016 and May 2017, we conducted a nationally representative cross-sectional telephone survey of 4964 US adults age 18 and over. Respondents who reported ever trying e-cigarettes were asked whether they ever experienced six symptoms they thought were caused by e-cigarette use. In weighted analyses, we assessed whether symptoms varied by demographics, e-cigarette use frequency, and cigarette smoking status.

Results: Approximately one-fourth of respondents (n = 1,624, 26.8%) reported ever trying e-cigarettes. Most were current (40.3%) or former (30.7%) cigarette smokers, with 29.0% never smokers. Just over half (58.2%) reported at least one symptom and on average 1.6 (SE = 0.1) symptoms. Symptoms included cough (40.0%), dry or irritated mouth or throat (31.0%), dizziness or lightheadedness (27.1%), headache or migraine (21.9%), shortness of breath (18.1%), change in or loss of taste (12.9%), or other (6.2%; most commonly nausea, tight chest, congestion). Among past 30-day e-cigarette users, current and never cigarette smokers were more likely than former smokers to report any symptoms (AOR = 5.25, CI = 2.05-13.46 and AOR = 2.58, CI = 0.85-7.81, respectively).

Conclusions: A majority of e-cigarette users reported at least one symptom, most commonly cough or dry or irritated mouth or throat. Former cigarette smokers who used e-cigarettes in the past 30 days were less likely than current or never smokers to report adverse symptoms of e-cigarette use. Future research should examine frequency of symptoms among different user groups to understand how e-cigarettes may influence public health.