A new Johns Hopkins study shows that data collected from wearable activity trackers can be used to derive a variety of metrics linked to a user’s general physical health and cardiovascular health status. Although these sensors are typically marketed as daily step counters, the Johns Hopkins research team believes they could potentially serve a larger purpose: supporting clinical care for patients with pulmonary arterial hypertension (PAH) and other chronic diseases.
The study was published NPJ Digital Medicine November 9.
The purpose of this study was to demonstrate clinically relevant metrics beyond daily step counts from these wearable activity monitors. Historically, remote monitoring of a patient’s physical condition has been challenging. We wanted to address that challenge and see what kind of redundant information these devices contain that could help our PAH patients.”
Zheng “Peter” Xu, PhD, is the study’s first author and a postdoctoral fellow at InHealth, a strategic initiative to advance precision medicine at The Johns Hopkins University.
The Cleveland Clinic provided the Johns Hopkins research team with activity tracker-derived data for 22 individuals with PAH who wore activity trackers between two clinic visits. At both clinic visits, Cleveland Clinic medical professionals recorded 26 health measures of each participant, including health-related quality of life, heart rate measurements and results of a commonly used aerobic capacity and endurance test known as the six-minute walk distance (6MWD). test
Using each participant’s minute-to-minute step rate and heart rate data, the Johns Hopkins team ascertained several metrics broadly related to physical health and cardiovascular function. These included heart rate distributions and the intensity and frequency of walking instances per week, as well as results from an analog version of the 6MWD test that the team called the free-living six-minute walk distance test. This data enables the team to understand each participant’s health status and identify subgroups among participants with similar metrics to each other.
To demonstrate that these data have potential for clinical use, the team compared activity-tracker metrics with 26 health metrics recorded during both clinic visits -; And some unexpected correlations were found. For example, an activity tracker-measured fitness assessment (based on step count and heart rate data) correlates with clinically measured levels of 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 metrics.
Finding many statistically significant differences in a relatively small cohort suggests that activity-tracker data may make it possible to identify surrogate markers of disease severity that can be monitored remotely. These data may contribute to the identification of potential patients who would benefit from more frequent clinic visits or specific medications.”
Peter Searson, Ph.D., senior author of the study, and Joseph R. and Lynn C. Reynolds Professor Johns Hopkins University Whiting School of Engineering
“We also believe that activity tracker-measured health parameters can serve as proxies for clinically measured health parameters in patients with chronic disease,” adds Searson.
Next, the research team is investigating whether these devices can support clinical care for patients with chronic obstructive pulmonary disease (COPD) and scleroderma. In collaboration with the Johns Hopkins COPD Precision Medicine Center of Excellence, they will determine whether signals from activity trackers can be used to predict the risk of COPD flareups.
Xu, Z., etc (2022) Assessing physical health status beyond daily step counts using a wearable activity sensor. NPJ Digital Medicine. doi.org/10.1038/s41746-022-00696-5.