By Dave DeFusco
At first glance, the Expanded Disability Status Scale seems like the perfect tool for measuring disability in patients with Multiple Sclerosis. It’s the most widely used global metric for quantifying the effects of the disease, which disrupts both physical and cognitive functions. But at the Katz School’s 2025 Graduate Symposium on Science, Technology and Health, Arielle Caplan, a student in the Occupational Therapy Doctorate, made a compelling case that the EDSS may be missing something vital.
Her project, “Measuring Cognition and Self-Care Ability in Multiple Sclerosis Using the Expanded Disability Status Scale,” explored how well EDSS correlates with patients’ actual ability to perform daily living tasks and with cognitive function—two domains critical to occupational therapy. What she found raises important questions about the scale’s relevance and calls for a broader, more holistic view of disability in MS care.
“The EDSS focuses heavily on mobility and physical symptoms, but it doesn’t give us the full picture of what our clients are experiencing,” said Caplan. “MS is a complex condition that affects how people think and feel, and manage their daily lives. We need to measure that, too.”
Caplan reviewed data from research on 160 adults with a clinical diagnosis of MS from South Shore Neurologic Associates. With ages ranging from 17 to 91 and a predominance of women (69.4%), the participants had undergone a battery of tests during routine care. They were categorized by EDSS disability level—mild (0 to 2.5), moderate (3 to 4.5) and severe (6 to 10)—and then assessed their ability to carry out Activities of Daily Living (ADL) using the Physical Self-Maintenance Scale (PSMS), as well as their cognitive performance using the NeuroTrax computerized testing system, which evaluates seven brain domains.
In terms of self-care, the correlations between EDSS scores and PSMS scores were weak to moderate at best, and the variability in PSMS scores was greatest among the most severely disabled. This suggests that even those with high EDSS scores—typically assumed to be very disabled—may still retain surprising levels of independence.
“In the severe disability group, we saw that some patients still performed daily activities with a level of autonomy not captured by the EDSS,” said Caplan. “That variability points to a blind spot in the current system.”
The picture was even more pronounced in the cognitive realm. The EDSS correlated weakly with nearly all cognitive domains tested—attention, executive function, memory, and so on. Verbal function showed no significant correlation at all. These findings align with previous studies that have found EDSS scores to be poor indicators of cognitive decline, despite the fact that up to 70% of people with MS experience some form of cognitive impairment.
Dr. Marissa Barrera, assistant dean of health sciences at the Katz School and an expert in MS, praised Caplan’s work for its potential to reshape clinical thinking.
“Arielle’s research underscores a critical point—that disability in MS cannot be understood through mobility alone,” said Dr. Barrera. “This kind of work is exactly why we value interdisciplinary training in our health sciences programs. It challenges outdated norms and pushes us toward more person-centered care.”
Dr. Gioia Ciani, director of the Occupational Therapy Doctorate program, emphasized the project’s real-world implications.
“Occupational therapists look at the whole person,” said Dr. Ciani. “If we’re going to support someone with MS, we need tools that reflect the actual challenges they face—not just how far they can walk. Arielle’s study is an important step toward more meaningful measurement.”
