In patients with multiple sclerosis (MS), disease progression and disability endpoints can be predicted by time to secondary progression, according to a 50-year follow up of an incidence cohort of 254 MS patients.
The study followed 212 adults with initial relapsing-remitting MS and 42 patients with a monophasic disease course and found:
• Median time to secondary progression was 15 years.
• Median times to Expanded Disability Status Scale 6 (EDSS6) and EDSS7 were 26 and 48 years, respectively.
• The cumulative risk of reaching EDSS6 was 50% at 55 years and 80% at 80 years.
• Age at onset predicted the disease course in men, with a 3 to 6% yearly increase in the risk of reaching disability milestones.
Citation: Tedeholm H, Skoog B, Lisovskaja V, Runmarker B, Nerman O, Andersen O. The outcome spectrum of multiple sclerosis: disability, mortality, and a cluster of predictors from onset. J Neurol. 2015;262(5):1148-1163. doi: 10.1007/s00415-015-7674-y.
Commentary: Long-term cohort information related to disability outcome and natural history of disease can provide long-term milestones to judge therapy efficacy. MS is a chronic disease with expensive therapies and increasing disability over time. A reliance on short-term studies, relapse rates, and physical examination remains a recipe for economic disaster. A cumulative risk of half of all patients reaching EDSS6 at age 55 is sobering and reflects the fact that therapy initiation at diagnosis, long-term treatment, and maintaining effective interventions to prevent accumulation of disability are key. Perhaps the long-term benchmark of disease stability with therapy intervention might justify early expenditure. More objective information is needed about disability milestones and reliable predictors of disease change at critical times to justify therapy efficacy for prevention of long-term disability. A sobering fact that remains is that this disease, despite a greater appearance of benign cases, can still be severe in the long term for many people. — Mark Gudesblatt, MD, Medical Director of the Comprehensive MS Care Center at South Shore Neurologic Associates in Islip, NY