Digital tools could be useful in studies of rare disorders: Review

Measuring gait changes, activity a promising area of rare disease research

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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Using digital tools to measure changes in gait and other aspects of physical activity outside of a hospital setting is a promising avenue for research in rare neurological disorders like Lambert-Eaton myasthenic syndrome (LEMS) — but more research is needed to validate these tools for use in studies.

That’s according to the review study, “The use of digital outcome measures in clinical trials in rare neurological diseases: a systematic literature review,” published in the Orphanet Journal of Rare Diseases.

“This review highlights several issues limiting the full integration of digital outcome measures into clinical trials and practice,” the researchers wrote.

Clinical trials, rigorously designed studies in human subjects, are the gold standard for testing whether a potential treatment works or not. Conducting trials in rare diseases including LEMS is challenging, however, because these conditions are by definition rare, which means few people are eligible to participate in trials.

One of the most important aspects of clinical trial design, especially when the number of patients is limited, is identifying outcome measures that can be used to objectively and accurately assess changes in symptom severity over time.

In recent years, there has been increasing interest in the use of digital tools for this purpose. These can include sensors that are worn on the body and collect data over time. A notable advantage of this approach is that, at least theoretically, these tools can be used as a patient goes about their daily life, potentially providing a more comprehensive assessment than tests that are only done in a clinic.

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139 studies covered more than 24 rare disorders

Here, a team of scientists in Belgium and the U.K. conducted a review of the published literature to assess the use of digital outcome tools in rare neurological diseases. The team identified 139 studies covering more than two dozen rare disorders, though none of them specifically looked at LEMS.

The researchers noted that, over the past decade, there’s been a sharp increase in the number of published studies using these technologies: “In 2011, there were two published studies that included digital outcome measures, whereas in 2022 there were 25,” the team wrote, noting that this increase reflects growing interest in the field.

Findings broadly suggested many of these technologies show promise, at least in early tests.

“A key finding of this review is that the use of digital outcome measures for motor function outside the clinical setting is feasible and it is being employed to evaluate subjects with a broad range of diseases,” the researchers wrote.

Despite the promise of these technologies, there’s still a long way to go, the scientists said. For starters, most of the studies included in this review were done only at a single center and included a small number of participants. And even when studies were testing technologies that could be used by patients in day-to-day life, the studies themselves were often limited to evaluations in a clinical setting.

Further studies needed to develop the needed technologies

“Although these devices are meant to be used at home, more than half of the evaluations in the studies took place in clinical setting. This indicates that many of these technologies are not yet ready to be used unsupervised,” the researchers wrote. They stressed a need for further studies to advance the development of technologies that can be used by patients outside of clinics.

The scientists also found that, while many tools have shown promise in individual studies, for most of the tools evaluated there isn’t yet enough evidence to be sure that they can reliably be used at the broad scale that would be required for clinical trials. They emphasized that further research still is needed to validate how well these tools can measure changes that are meaningful from a patient perspective.

“It is generally assumed that digital outcomes will be more sensitive to change in patient condition than standard tests and scales; however, this has yet to be proven,” the scientists wrote.

The team also noted that many different equipment setups were used across the studies, which makes it hard to perform meaningful comparisons from one study to another.

“Future research should focus on the systematic validation leading to the qualification of devices, variables, and algorithms to allow remote evaluation of diseases,” the scientists wrote. They noted that using open-source data collection platforms to publicly pool data may help to accelerate these processes to get the full potential benefit out of this emerging technology.

“It is clear from the current state of the field that digital outcome measures have great potential to positively impact clinical trials and accelerate drug development processes,” the researchers concluded.