The Annals of Emergency Medicine isn’t a journal we crack all the time around here, but it carries an article that describes how data collected by a patient’s Fitbit Charge HR helped diagnose a life-threatening condition.
The article’s a bit technical, but the deal is that the patient showed up with cardiac arrhythmia. If the arrhythmia was chronic, one treatment was indicated; if not, a very different treatment would have been correct. The wrong one could have killed the patient.
Doctors, noticing that the guy was wearing a Charge HR, went into his Fitbit app and checked his history. Bingo: not chronic. The patient was treated accordingly, and all was well.