Apple and Stanford University School of Medicine today issued press releases and cited the results of the Apple Heart Study that they jointly announced in November 2017. Stanford Medicine also made its findings to the American College of Cardiology 68th Annual Scientific Session and Expo in day. Apple fully funded the study.
The Apple Heart Series, which did not include Apple Watch Series 4 (with built-in ECG function), included 419,093 participants. Apple says that people from all 50 states participated for eight months, and according to the university, about 0.5 percent of all participants ̵
In cases where users received irregular cardiac arrhythmias, physician study participants provided digital consultation, as well as an electrocardiogram patch for further monitoring.
Stanford has more on how all this shook:
Comparisons between irregular pulse detection on Apple Watch and simultaneous electrocardiography (ECG) patch recordings showed the pulse detection algorithm (indicating a positive tachogram reading) has a 71 percent positive predictive value. 84 per cent of the time showed participants who received irregular pulse messages during atrial fibrillation at the time of notification.
One third (34 percent) of the participants who received irregular heart rate messages and followed up with an ECG patch over a week later were found to have atrial fibrillation. Since atrial fibrillation is an intermittent condition, it is not surprising that it will be undetected in subsequent ECG patch monitoring.
Fifty-five percent of those who received irregular heart rate messages sought medical attention.
From the sound of it, Stanford treats the Apple Heart Study as a step in further research on how useful portable consumer devices can monitor our daily health and predict problems. "Atrial fibrillation is just the beginning, as this study opens the door to further investigate portable technology and how they can be used to prevent disease before it hits – an important goal for Precision Health," said Doctor Lloyd Minor, Stanford Stanford Medical School.
We know that these devices (from Apple and many other companies) can and continue to save and improve lives, but catching undiagnosed health issues is several layers beyond the core activity monitoring and whether your heart beats as it should, which is data for most consumer items today. There is little room for errors if technicians want to take the next step. And again, this study only involved Apple Watch up through Series 3, so it was highly dependent on the device's optical heart rate sensor. When you are stuck for a heart control at a medical facility, there is more specialized equipment at hand.
"The performance and accuracy we observed in this study provides important information when we try to understand the potential impact of portable technology on the health system," said Dr. Marco Perez, associate professor of cardiovascular medicine. "Further research will help people make more informed health decisions."
Apple with its newer Apple Watch Series 4 has tried to clarify that the ECG function is not a kind of medical diagnostic tool. If there are several consecutive abnormal readings, it will flag it to you. These devices are not for self-diagnosing your health or acting on the information they display without seeking incomes from a real doctor. Smartwatches and fitness trackers can detect irregularities or sudden cases, but are not yet in a place where anyone should fully trust them to do so.