How useful is the expanded disability status scale to neuropsychiatrists?

BACKGROUND

The Expanded Disability Status Scale (EDSS) is a gold-standard disability measure in multiple sclerosis (MS) notwithstanding its inbuilt bias towards pyramidal function.

OBJECTIVES

To determine whether differences in EDSS-measured disability severity reflect the neuropsychiatric sequelae of MS.

METHODS

In a consecutive sample of 1277 people with a confirmed diagnosis of relapsing-remitting MS (RRMS), EDSS scores were classified as "no disability" (0-1.0), "mild disability" (1.5-2.5), and "moderate-severe disability" (3.0-7.5). The ability of the EDSS (compared to a reference level of "mild disability") to predict global cognitive impairment (GCI; assessed with the Minimal Assessment of Cognitive Function in MS), anxiety and depression (Hospital Anxiety and Depression Scale anxiety and depression sub-scales), fatigue (Modified Fatigue Impact Scale), and self-perception of deficits (Perceived Deficit Questionnaire) was determined with regression analyses (linear or logistic where appropriate).

RESULTS

Mean age was 41.79 years (SD=10.27), 75.47% were female, and median EDSS was 2.0 (IQR=1.5-2.5). "No disability" was associated with less GCI (OR=0.71), depression (β=-0.09) and fatigue (β=-0.09) and fewer perceived deficits (β=-0.09), all p < 0.05. "Moderate-severe disability" was associated with increased GCI (OR=2.39), depression (β=0.10), and fatigue (β=0.13), all p < 0.05.

CONCLUSIONS

Increased EDSS-measured disability is accompanied by rises in GCI, depressive symptoms, and fatigue, but not anxiety.