Stanford study reveals accurate ‘frailty’ assessment results through Apple Watch
29th March, 2021 at 3:44 am by Yash and André
- The research was carried out by Stanford University and funded by Apple.
- At-home six-minute walking tests (6MWT) were conducted on a regular basis and later compared to clinical results.
- It used a specifically-designed app for acquiring the data.
- The results proved to be of great accuracy.
New results published by Stanford University (via MyHealthyApple) have proven that the Apple Watch can accurately evaluate the “frailty” of a person.
The study conducted by Stanford University researchers used the six-minute walking test (6MWT) score to assess the “frailty” of the patients. A six-minute walking test (6MWT) is a standard assessment to determine the frailty, with the metrics being used to evaluate the functional mobility and exercise capacity of the person. Higher scores highlight a healthier cardiac, circulatory, respiratory and neuromuscular function of a person, according to Apple. The entire study was funded by Apple.
All 110 Veterans Affairs Patients with cardiovascular disease were provided with an iPhone 7 and an Apple Watch Series 3. Regular at-home six-minute walking tests were then conducted by the Patients. Data was collected by an app called “VascTrac” alongside the passively collected Activity data. Outcomes of these regular tests were hence compared with the patients’ typical in-clinic six-minute walking test result.
We enrolled 110 participants who were scheduled for vascular or cardiac procedures. Each participant was supplied with an iPhone and an Apple Watch running the VascTrac research app and was followed for 6 months. Supervised 6MWTs were performed during clinic visits at scheduled intervals. Weekly at-home 6MWTs were performed via the VascTrac app. The app passively collected activity data such as daily step counts. Logistic regression with forward feature selection was used to assess at-home 6MWT and passive data as predictors for “frailty” as measured by the gold-standard supervised 6MWT. Frailty was defined as walking <300m on an in-clinic 6MWT.
Following the results, it was found that the Apple Watch could accurately assess the frailty with a 90% sensitivity and 85% specificity under a supervised clinical setting. Under an unsupervised setting at home, the Apple Watch could accurately assess frailty with 83% sensitivity and 60% specificity. Therefore, the study drew the conclusion that the Apple Watch is an accurate forecaster of a user's frailty.
In this longitudinal observational study, passive activity data acquired by an iPhone and Apple Watch were an accurate predictor of in-clinic 6MWT performance. This finding suggests that frailty and functional capacity could be monitored and evaluated remotely in patients with cardiovascular disease, enabling safer and higher resolution monitoring of patients.” Inspired by the study, which used a specifically-designed app for gathering the 6MWT data alongside the passively-collected activity data, Apple has since incorporated a series of new mobility-related health metrics in watchOS 7, including the 6MWT and described it as a “golden standard to evaluate the functional mobility of a patient.
Besides all this, it’s not the first time Apple Watch has proven itself capable of diagnosing the user’s medical conditions. Back in January 2021, it was proven through a research that Apple Watch is able to detect the COVID-19 infections in the user. Further, wearing the watch on a regular basis ensures that it will keep checking for signs of AFib, irregular heart rhythm and Cardio Fitness (VO2 Max) levels, which are critically important for a user’s mental as well as physical health. A complete result of the study can be found here.