Hua, My, et al. "Health effects associated with electronic cigarette use: automated mining of online forums." Journal of medical Internet research 22.1 (2020): e15684.

This study aimed to automate the extraction and analysis of health-effect data related to electronic cigarette (EC) use from over 1.4 million online forum posts spanning 2008 to 2015. Using a modified MetaMap tool, the research analyzed 41,216 posts to categorize symptoms and disorders into 12 organ systems. Most posts reflected negative sentiments, with frequent reports on neurological, mouth and throat, and respiratory systems. Common symptoms included headache, coughing, malaise, and asthma, with users often reporting linked symptoms.