Wearable activity tracker data can be used to obtain metrics related to a user’s physical health

A new Johns Hopkins University study shows that data collected from wearable activity trackers can be used to obtain several metrics associated with a user’s general physical health and cardiovascular health status. While these sensors are generally marketed as daily pedometers, the Johns Hopkins research team believes they could serve a larger purpose: supporting clinical care for patients with pulmonary arterial hypertension (PAH) and other chronic diseases.

The study has been published in digital medicine npj On November 9th.

The purpose of this study was to show that clinically relevant measures beyond daily step count can be derived from wearable activity monitors. Historically, remote monitoring of a patient’s physical condition has been a challenge. We wanted to take on this challenge and see what kind of untapped information is in these devices that can help us support patients with PAH.”

Zheng “Peter” Xu, PhD, study first author and postdoctoral fellow at inHealth, a strategic initiative to advance precision medicine at Johns Hopkins University.

The Cleveland Clinic provided the Johns Hopkins research team with data obtained through activity tracking for 22 individuals with PAH who wore activity trackers between two clinic visits. At both clinic visits, Cleveland Clinic medical professionals recorded 26 health measurements for each participant, including health-related quality of life, heart rate measurements and results from a commonly used aerobic capacity and endurance test known as the Six-Minute Walking Distance (6MWD) test.

Using accurate step rate and heart rate data for each participant, the Johns Hopkins team validated several measures widely associated with physical health and cardiovascular function. This included the distribution of heart rate, intensity and frequency of walks over each week, as well as results from a representative version of the 6MWD test that the team called the Six-Minute Walking Distance Test. This data enabled the team to understand each participant’s health status and to identify subgroups among the participants who had similar measures to each other.

To prove that this data has potential for clinical use, the team also compared the activity tracker metrics with 26 health metrics recorded during both clinic visits – ; And I found some unexpected connections. For example, a fitness assessment measured with an activity tracker (based on step count and heart rate data) correlated with clinically measured levels of NT-proBNP, a blood biomarker used to assess risk of heart failure. Across the 22 participants, the research team found significant differences in 18 of these measures.

Finding so many statistically significant differences in a relatively small cohort suggests to us that activity-tracking data may make it possible to identify surrogate markers of disease severity that can be monitored remotely. This data can contribute to identifying patients who might benefit from more frequent clinic visits or specific medications.”

Peter Sierson, Ph.D., senior author of the study and Joseph R and Lynn C. Reynolds Professor in the Whiting School of Engineering at Johns Hopkins University

“We also believe that health parameters measured with an activity tracker can serve as proxies for clinically measured health parameters of chronically ill patients,” Searson adds.

Next, the research team is exploring whether these devices can support clinical care for patients with chronic obstructive pulmonary disease (COPD) and scleroderma. In collaboration with the Johns Hopkins University Precision Medicine for COPD Center of Excellence, they will seek to determine whether signals derived from activity trackers can be used to predict the risk of a COPD flare-up.


Journal reference:

Shu, ze. , et al. (2022) Assessment of physical health status following daily step count using a wearable activity sensor. digital medicine npj. doi.org/10.1038/s41746-022-00696-5.

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