Data from a wearable activity tracker can be used to obtain metrics related to the user’s physical health

A new Johns Hopkins study shows that data collected from activity tracking devices can be used to derive several metrics related to the wearer’s general physical health and cardiovascular health. While these sensors are typically marketed as daily step counters, the Johns Hopkins research team believes they could potentially serve a larger purpose: aiding clinical care for patients with pulmonary arterial hypertension (PAH) and other chronic diseases.

The study was published in npj Digital Medicine on November. 9.

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

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

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

Using each participant’s minute-by-minute step rate and heart rate data, the Johns Hopkins team identified several metrics broadly related to physical health and cardiovascular function. These included heart rate distributions and the intensity and frequency of walking events during each week, as well as results from an analog version of the 6MWD test, which the team called the six-minute free-living walking distance test. This data allowed the team to understand the health status of each participant and identify subgroups among participants with similar indicators to each other.

To demonstrate that these data have potential for clinical use, the team also compared the activity trackers with the 26 health indicators recorded during the two clinic visits -; and found some unexpected correlations. For example, a fitness score measured by activity tracking (based on step count and heart rate data) correlates with levels of clinically measured NT-proBNP, a blood biomarker used to assess heart failure risk. Among the 22 participants, the research team found statistically significant differences in 18 of these measures.

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

Peter Searson, PhD, senior author of the study and the Joseph R. and Lynn S. Reynolds Professor at the Whiting School of Engineering at Johns Hopkins University

“We also believe that health parameters measured by activity tracking can serve as surrogates for clinically measured health parameters in patients with chronic diseases,” adds Searson.

The research team then investigated whether these devices could support clinical care for patients with chronic obstructive pulmonary disease (COPD) and scleroderma. In collaboration with the Johns Hopkins COPD Center of Excellence in Precision Medicine, they will seek to determine whether signals obtained from activity trackers can be used to predict the risk of COPD exacerbations.


Journal reference:

Sue, Z., et al. (2022) Assessment of physical health beyond daily step count using a wearable activity sensor. npj Digital Medicine.

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