This research from the US looked at developing a reference table of disability outcomes in MS, which would be of benefit to patients so they can rank their disability relative to others and from a research perspective it could be used for comparing MS severity across patient populations and time periods, and so it could be used as a cost effective outcome measure in epidemiological studies.
The cohort consisted of 27,918 North American Research Committee on Multiple Sclerosis (NARCOMS) enrolees. This registry collects disability data from MS patients on a validated 9-point Patient-Determined Disease Steps (PDDS) scale. From this they compiled the Disability Expectancy Table, which displays cumulative frequencies of PDDS scores for each year of disease duration, from 0-45 years.
Also, they looked at disease duration-adjusted mean ranks of PDDS scores, which they called Patient-derived MS severity Scores (P-MSSS). Both the Disability Expectancy Table and P-MSSS give a detailed overview of disability outcomes in a larger MS cohort over 45 years.
The researchers found that in the first year of disease, 15% of patients reported need of ambulatory aid and 4% needed bilateral aid. After 45 years of disease, 76% needed ambulatory aid and 52% needed bilateral assistance or worse. Those that required minimal or no interference in daily activities reduced from 63% in the first year to 8% after 45 years.
Overall, the Disability Expectancy Table allows individual patients to determine their disability rank relative to NARCOMS enrolees with the same disease duration. In addition to this, P-MSSS may be used to compare disability across patient populations and track disease progression over time.
Authors: Kister I, Chamot E, Salter AR
Source: Neurology. 2013 Feb 20. [Epub ahead of print]
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