Disability in multiple sclerosis: a reference for patients and clinicians.

Area of Science:

• Neurology
• Epidemiology
• Patient-Reported Outcomes

Background:

• Multiple sclerosis (MS) significantly impacts patient disability over time.
• Standardized tools are needed to quantify and compare MS-related disability.
• Existing methods may not be cost-effective or easily applicable in large-scale studies.

Purpose of the Study:

• To develop a reference table (Disability Expectancy Table) for patients to contextualize their MS disability based on disease duration.
• To create a cost-effective research tool (Patient-derived MS Severity Scores - P-MSSS) for comparing MS severity across populations and over time.

Main Methods:

• Utilized data from the North American Research Committee on Multiple Sclerosis (NARCOMS) Registry, including 27,918 patients.
• Employed the validated 9-point Patient-Determined Disease Steps (PDDS) scale for disability assessment.
• Compiled a Disability Expectancy Table showing cumulative PDDS frequencies by disease duration (0-45 years) and calculated disease duration-adjusted P-MSSS.

Main Results:

• The Disability Expectancy Table and P-MSSS provide a detailed overview of disability in a large MS cohort over 45 years.
• After 45 years of disease, 76% of patients required ambulatory aid and 52% needed bilateral assistance or worse.
• The proportion of patients with minimal daily activity interference (PDDS ≤ 1) decreased from 63% in year one to 8% after 45 years.

Conclusions:

• The Disability Expectancy Table empowers individual MS patients to benchmark their disability against peers with similar disease duration.
• P-MSSS offers a practical, cost-effective measure for comparing MS severity across patient groups and tracking disease progression in research.
• P-MSSS's independence from formal neurologic examination enhances its utility in large epidemiologic studies.