If you are among the millions of smartwatch owners with a cardiac abnormality detection feature, you might very well have tried this feature on yourself. But what would you do if it told you that you have atrial fibrillation (AFib), an irregular heart rhythm disorder that increases stroke risk? If you don’t have a history of cardiovascular ailments, you might, at first, think it’s an issue with the firmware, an incorrect reading or even a faulty device.
But what if the result persists after several tests; and even after other people who used the same watch showed normal results? You would likely consult your physician to determine if there’s a need to worry. If the results are negative, then all the better. But if your physician’s tests corroborate with the smartwatch’s results, then you could undergo potentially life-saving treatment.
This is exactly what happened to Zsolt Varga, an IT professional from Budapest, who we interviewed earlier. The Apple Watch he received as a Christmas present correctly notified him of a previously undiscovered AFib. This allowed him to take preventive measures and have his physician monitor his condition well before any complications arose. And Mr Varga is not the only one turning to the ER following notification of their smartwatch.
Recently an Apple watch also saved its owner’s life who had internal bleeding which was discovered after repeated notifications from the device. The more people wear such devices, the more often we read similar stories.
ECG capabilities are embedded in a growing number of smartwatches, and will soon become a standard feature. And sensors are becoming better and better, there are developments promising even more advanced features (like core body temperature, blood pressure, hydration, and blood alcohol and glucose measurements) in the future.
Smartwatch AFib detection has its limitations. Notably: people who use such devices are typically not members of high-risk groups. While watch owners are statistically young (under 45) and most likely financially not deprived, AFib is much more prevalent in the 65+ population and due to a number of factors, is more common in people with lower incomes. (These factors include high blood pressure, obesity, and diabetes – all risk factors for AFib and more prevalent among people with lower incomes. Additionally, access to healthcare and quality of healthcare can also impact AFib diagnosis and management.)
Thus we can conclude that as of now, many people who could benefit most from the devices aren’t wearing them – and might not be able to afford them.
Nevertheless, as we explain in this article, technology is not at fault here. It’s rather the lack of the cultural transformation that is required as part of digital health adoption that’s missing from the equation. So let’s break down the misconceptions and reality behind having your smartwatch send you to the hospital.
What the research says
There had been quite some evolution in the past decade.
This paper from Mayo Clinic from a few years back found that among the 264 Apple Watch users’ analysed clinical data, only 11.4% received clinically actionable diagnoses. “For patients who experienced an abnormal pulse alert and presented for medical evaluation, 7 patients needed to be evaluated to establish 1 diagnosis of clinically actionable cardiovascular disease,” the researchers explained. “Among the 15 asymptomatic patients who presented following an abnormal pulse alert, only 1 was diagnosed with a clinically actionable cardiovascular diagnosis.”
Their findings further suggest that “many users used the device in a manner inconsistent with FDA guidance.” That FDA guidance about the abnormal pulse detection stated that “the feature has not been tested for and is not intended for use in people under 22 years of age. It is also not intended for use in individuals previously diagnosed with AFib.” In their study, the researchers found that 8.7% of patients were under 22 years of age, while 22% had preexisting atrial fibrillation.
They concluded by writing that “the FDA and Apple must carefully consider the unintended consequences of widespread direct-to-consumer screening for asymptomatic atrial fibrillation, including overutilization of healthcare resources owing to false positive screening results and use of screening tools by users in whom they have not been adequately studied.”
However, as the technology evolved, new features emerged. FDA approved Apple Watch AFib history feature in 2022, allowing adults with the condition to track how frequently they show signs of irregular heartbeat. They also have data on how certain factors like sleep, alcohol consumption and activity may be impacting their AFib, and can download a detailed PDF combining all of that information they can share with their doctors.
And there is another interesting line of development. “A 2021 retrospective analysis of the Apple Heart Study – which served as the basis for FDA clearance of the Apple Watch’s ECG – found that the device may be able to identify arrhythmias other than AFib. The study looked specifically at wearers who had received an irregular pulse notification but hadn’t been subsequently diagnosed with AFib. The researchers found that about 40% of that group went on to be diagnosed with a different form of arrhythmia.” So, circling back to the initial findings on false positives from a few years ago: it looks possible that a visible share of those alarms has actually been valid – not for AFib, but for other irregularities.
Through these studies, many will blame the technology or even the tech adopters for potentially over-burdening hospitals. However, the real issue lies deeper than that.
The misconceptions (and reality) behind a smartwatch “diagnosis”
When a device like the Apple Watch receives clearance from a regulatory body like the FDA, expectations are understandably high. But sometimes, they are higher than they should be. People come to expect these technologies to make perfect measurements with no room for mistakes. But the truth is, even with high false positive rates, digital health devices still detect more patients; especially if they are asymptomatic. In the U.K. alone, the British Heart Foundation puts the number of those with AFib but oblivious to the risk at around 300 000.
The 11.4% smartwatch users that the Mayo Clinic found to have clinically actionable diagnoses translates roughly to 1 in every 10 patients who present with a smartwatch alert. That’s like identifying Mr. Varga’s case and 9 false positives; but we’re still catching that 1 patient before they experience a stroke. That’s a win for the patient who would otherwise have slipped through the traditional system; and a win for digital health.
Additionally, one might think that it’s the technology, rather than the actual health issue, that sends patients to hospitals; hence the term smartwatch “diagnosis.” But if a patient has an underlying ailment without their prior knowledge, the smartwatch’s sensor only detects what’s already there.
A better approach to prevention
Importantly, a digital health device like a smartwatch still presents a better approach to preventing complications than the current methods. The latter, unfortunately, all too often means doing nothing or waiting for the patient to exhibit strong symptoms. With digital health tools, we still correctly identify the patient demographic that the traditional healthcare system misses.
Yes, the false positives will add to the workload and resource utilisation; and more patients will show up to the ER following alerts from their smartwatches in the near future. For example, Apple released the Apple Watch 6, which included a blood oxygenation sensor. A drop in the oxygen saturation (SpO2) level the sensor measures can indicate an underlying respiratory illness, even if no visible signs are present. While Apple did not seek FDA clearance for this sensor, it’s not far-fetched to imagine users rushing to their physicians following an abnormal result.
As the medical knowledge about the use of such smart wearables accumulates, as more studies set out to determine the true preventive/therapeutic potential, we can declare with increasing confidence that these devices can indeed improve our health outcomes in general.
How to deal with “smartwatch patients”?
Rather than being the object of scorn for taking their smartwatch readings too seriously, adopters of such digital health tools need guidance from medical professionals.
And for that, those healthcare professionals must themselves understand and be open to those disruptive technologies. This is because simply making clinical-grade sensors available to patients will not yield optimal results. As the recent Mayo Clinic study showed, it can even lead to the overburdening of healthcare institutions. But proper guidance from medical professionals can equip patients to better interpret readings from their smart sensors, which will, in turn, help avoid unnecessary hospital visits.
Doctors can follow guidance from regulatory authorities around the use of such devices. They can further instruct their patients regarding who should take and when to take measurements with these wearables. Patients can in turn share their data over the cloud with their physician in case of suspicious readings. They can subsequently both discuss those findings over a telemedicine consultation and determine if a hospital visit is indeed necessary.
As such, the method to deal with those so-called “smartwatch patients” is not avoiding those novel technologies.
Rather, it involves investing in and supporting digital health technologies that facilitate the doctor-patient relationship as an equal-level partnership.
In short, we need a cultural transformation, and this is part and parcel of digital health; in fact, it is part of its very definition. Without such a transformation, digital health cannot take off. It will have a polarised adoption, with patients seeking those technologies while healthcare professionals warding them off. This will be at the expense of the obvious advantages disruptive technologies bring to the field that truly propel healthcare into the 21st century.