Apple-funded Stanford study concludes Apple Watch can be used to measure frailty

New study on the effectiveness of Apple Watch and iPhone as tools for measuring functional capacity in patients with cardiovascular disease (CVD) has been published by researchers at Stanford University .

The study, which involved 110 participants, found that the health monitoring capabilities of these products could complement or replace clinical testing for “frailty” in patients with CVD.

Brittleness in this case is measured in terms of how far a patient can walk in a six-minute walk. This is normally tested with a six-minute walk test (6MWT), and frailty was defined in the study “as walking

The study found that an Apple Watch was able to accurately assess frailty with specificity of 85% and sensitivity of 90% in a supervised clinical test. But the potentially significant result is that he was able to do the same thing with precision with 60% specificity and 83% sensitivity in unsupervised home tests.

The researchers therefore concluded that the watch was precise enough to replace clinical testing in many circumstances. Here’s what the researchers’ article said about the test results:

In a supervised clinic setting, the smartphone and the Apple Watch with the VascTrac application were able to accurately assess “fragility” with a sensitivity of 90% and a specificity of 85%. Outside of the clinic in an unsupervised environment, home 6MWT is 83% sensitive and 60% specific for assessing “frailty”. Passive home data were almost as accurate in predicting frailty on a clinic 6MWT as a home 6MWT was, with area under the curve (AUC) of 0.643 and 0.704, respectively.

And here is their conclusion:

While the benefits of telemedicine and remote monitoring – convenience, low cost, improved data quality – have been postulated for some time, the COVID-19 pandemic has made fast-track implementation a security imperative. . In this study, we showed that smart device-based measurements, including both 6MWT and passively collected activity data, provide clinically accurate and meaningful information on the functional capacity of CVD patients.

You can read the full article on PLOS One. It’s important to note that while the study was conducted independently, it was funded by Apple. In addition, the study has a small sample size and the sample size did not include much demographic diversity.

Apple may have funded the study to help with marketing or lobbying for acceptance of an Apple Watch for this use case, or the company may have commissioned the study to use the results to inform decisions about the health features to invest in for the watch.

After the study work was completed, the researchers had to use an app called VascTrac to run the tests. But Apple has since added the 6MWT test as a built-in feature of watchOS, so an additional app would no longer be needed.

Apple CEO Tim Cook said he sees wearable devices like the Watch as the future of the company in many ways, and many of the advancements in innovation and adoption made by the company in recent years have been in this category. Studies like this help the company demonstrate that its products solve real-world problems.

That said, Apple’s claims on this front don’t always come under scrutiny. For example, some doctors have expressed concern that the Watch’s attempts to identify atrial fibrillation are not adequately replacing more robust tests and that the readings may lead to negative results for patients if they are. misused.