This is the second half of a two-part story on the use of digital step trackers in MS patients. Read Part One first.
What More Can the Step Trackers Tell Us?
As mentioned in part one of this story, the study done by Valerie Block, PT, DPTSc, had a retention rate of 83 percent. That meant that 79 MS patients using wearable step trackers completed the study, and analysis of their EDSS scores placed them in one of three categories:
- Those who improved in function (their EDSS score decreased)
- Those who had no change in function (their EDSS score stayed the same)
- Those who had a worsening of function (their EDSS score increased)
In addition to the change that occurred, the participants in Block’s study were also at varying levels of ability to start with. Some had no disability (EDSS score of 0) and others needed as many as two walking aids to get around (EDSS score of 6.5). Their daily step counts (at the start and throughout the study) also varied with their disability. This offered another opportunity for analysis of the data: looking at step counts over the year and how they were affected by the patient’s initial level of disability.
When Block did this analysis, one group stood out. The patients who were the most disabled—their daily step counts were below the cohort median of 4,800 daily steps—showed the biggest decrease in step count over the year. In other words, those who were the most disabled and took the fewest steps initially were the ones who showed the greatest decline in step count over the year.
“Not only do we see that there was a significant decrease in steps for this group over the year,” said Block, “but also there were four times the odds of clinically-meaningful worsening, as defined by EDSS.” Block says this may be an important prognostic metric that can be remedied through neuro rehabilitation (she is a physical therapist, after all).
When Block and her team stepped back and took a closer look at those who had no change in function (per their EDSS score) over the year, they found something interesting related to their step counts—they still went down. Could it be that step counts offered a more subtle decrease in function than the EDSS could pick up?
“I want to just highlight the EDSS six (where someone needs a cane to walk),” said Block. “These people didn’t have a change in EDSS, and yet, over the year there was a significant decrease in steps.” In other words, “There was worsening in steps that was not captured by these other metrics.”
To sum up—a deeper dive into the data revealed two clinically relevant findings:
- Step counts declined more rapidly in patients with more disability
- Step counts went down even when EDSS scores remained constant
And Block is not finished yet. She is continuing to delve into the data collected from this study and is taking this same cohort forward another year. She is hoping to present more information at the next meeting of the American Academy of Neurology. We’ll keep our ears to the ground for that—’cause this research has got legs.