The Apple Watch has been touted as the most accurate wrist-based wearable in a new study from the Cleveland Clinic, published in JAMA Cardiology.
The study was performed on 50 healthy adults, who wore an electrocardiogram (EKG), Fitbit Charge HR, Apple Watch, Mio Alpha, Basis Peak, and a chest strap for several hours.
Participants performed a variety of exercises to test wearable accuracy during rest, walking, and on a treadmill. The study found the chest strap monitor to be the most accurate, at 99 percent success rate.
The Apple Watch came second, with a success rate of 90 percent. That might seem like a major slump from 99 percent, but it far surpasses the other wearables tested, which were in the low 80s.
As intensity increased, the Cleveland Clinic found that accuracy decreased across the board. That is partly due to wearables tracking blood flow to determine heart rate, which can be inaccurate.
“What we really noticed was all of the devices did not a bad job at rest for being accurate for their heart rate, but as the activity intensity went up, we saw more and more variability,” said Dr. Gordon Blackburn, one of the study authors and director at the Cleveland Clinic. “At the higher levels of activity, some of the wrist technology was not accurate at all.”
Fitbit has commented on the study, pointing out that its wearables are not medical devices and provide much more comfort than the chest strap monitor. The company also said that internal tests showed 94 percent success rate, though those tests remain undisclosed.
Wearables have become far more accurate in the past few years, but Cleveland Clinic’s study clearly shows there’s more work to be done. Some of it can be ironed out by removing false positives after the data has been collected, but to reach 99 percent wearable providers need to upgrade sensors or look beyond the wrist.