Measuring population health using personal health messages.

Personal health messages - inter patient communications within online communities; represent a new path towards providing continuous information about patient derived health status. We apply natural language processing techniques to personal health messages from online message boards to demonstrate the ability to track trends in people's positive or negative opinion (sentiment) regarding particular drugs over time. The significant changes in sentiment correspond to FDA announcements and other publicity. We envision such analysis as a scalable tool for pharmacovigilance hypothesis generation for possible adverse drug reactions.