IMPAIRMENT AND DISABILITY - THEIR RELATION DURING STROKE REHABILITATION

Objectives: To describe the association between impairment and disabil ity during stroke rehabilitation and to examine the effects of rehabil itation by studying the degree of disability reduction experienced by stroke patients who did not have significant reductions in impairment levels. Design: Statistical analysis of items from a database of prosp ectively collected information on stroke patients admitted for rehabil itation, Setting: Large urban academic freestanding rehabilitation fac ility. Participants: Four hundred two patients consecutively admitted for comprehensive acute stroke inpatient rehabilitation. Main Outcome Measures: The National Institutes of Health Stroke Scale (NIHSS) was u sed to measure impairment and the Functional Independence Measure (FIM SM) was used to measure disability. Motor and cognitive subscales of t he FIMSM instrument were evaluated, Raw NIHSS and FIMSM scores were co nverted to linear measures using Rasch analysis, Methods: Relationship s were studied between converted NIHSS and the two FIMSM subscales for admission, discharge, and change scores using linear regression analy sis, In a second analysis, two groups of patients were identified; the 342 patients who experienced no substantial reduction of impairment c omprised the ''no impairment reduction (NIR) group,'' and the 60 patie nts who had a significant reduction of impairment level comprised the ''impairment reduction (IR) group.'' Multivariate analysis of variance was used to determine and compare the amount of change in motor and c ognitive FIMSM measures over time for each of the two groups, Results: NIHSS correlated significantly with motor and cognitive FIMSM subscor es for admission, discharge, and change measures; R-2 values ranged be tween .02 and .36. Both the NIR group and the IR group experienced sig nificant decreases in disability during rehabilitation, The difference s in discharge FIMSM measures between the two groups were relatively s mall. Conclusions: Although stroke-related impairment and disability a re significantly correlated with each other, reduced impairment level alone does not fully explain the reduced disability that occurs during rehabilitation. Even patients without substantial impairment reductio n demonstrate disability reduction during rehabilitation, suggesting t hat rehabilitation has an independent role in improving function beyon d that explained by neurologic recovery alone. (C) 1998 by the America n Congress of Rehabilitation Medicine and the American Academy of Phys ical Medicine and Rehabilitation.