Data is pouring in from more than 100 million wearable devices worldwide that can track your steps, sleep patterns, blood pressure, heart rate, energy levels and a whole range of other measures. There’s just one problem, says Dr. Karl Poterack, director of applied clinical informatics at Mayo Clinic: “We don’t know if this data can predict or change [health] outcomes. We need to figure that out.”
 
Poterack gave a talk this morning that dumped a bit of ice water on outsized expectations that broad-based data collection is on the cusp of transforming medical practice. He urged the audience to keep a few points in mind before dumping more dollars, and time, into data collection:

• The device makers aren’t just giving you your own data: “If you aren’t aware of this, you should be — the vendors are collecting your data,” Poterack said. “Fitbit alone has data on over 75 trillion steps and over 3 billion nights of sleep.” That does not mean the data collection is nefarious, just that you ought to keep your eyes open.
• The vast majority of these devices are not medically controlled: That means health providers have not validated their accuracy and do not ensure they are calibrated correctly. “This is huge,” Poterack said. “Many of these devices are very robust and provide pretty accurate data … but they are not medical grade.” 
• Doctors don’t yet have much use for your data: Because of that previous point — and a general lack of clinical evidence — things like step counts don’t mean all that much to physicians. “If you say, ‘I want to give you this data to help take better care of me,’ your doctor is going to say, ‘It’s great that you’re active — 8,000 steps this day, 9,000 the next … I don’t know what it means,’” Poterack said.

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