Background and purpose: The purpose of this study was to examine the relationship between the Modified Rankin Scale (MRS) and poststroke recovery in neurological deficits, activities of daily living (ADL), higher level of physical and social functioning and the patients' preference for health state.
Methods: Four hundred and fifty-nine participants in the Kansas City Stroke Study were prospectively assessed for measures of MRS, NIH Stroke Scale (NIHSS), Barthel ADL, SF-36 physical functioning, SF-36 social functioning, and Time Trade-Off (TTO). ANOVA and Bonferroni multiple comparisons were used to examine any differences in 3-month scores of NIHSS, Barthel ADL, SF-36 physical functioning, SF-36 social functioning and TTO between levels of the MRS. In addition, SF-36 physical functioning, SF-36 social functioning and TTO were characterized in patients who demonstrated improvement in global MRS outcome and also achieved a Barthel Index (BI) > or = 95 at 3 months after stroke.
Results: Two hundred and eighty patients (62%) shifted at least one grade in MRS from baseline to 3 months after stroke. Only 67 or 194 patients were considered to have a favorable outcome using MRS 0/1 or MRS 0/1/2, respectively, as criteria. Mean 3-month NIHSS and Barthel ADL scores were not significantly different between Rankin 0/1 and 2, but they were significantly different among Rankin 3, 4 and 5 (all p < 0.05). Mean 3-month scores of physical functioning and SF-36 social functioning were significantly different among Rankin 0/1, 2, 3 and 4 (all pairwise p < 0.05). Proportions of patients who achieved NIHSS < or = 1 or BI > or = 95 decreased as MRS grades worsened. In patients who showed improvement in MRS global outcome and also achieved BI > or = 95, mean scores on TTO were similar.
Conclusions: Definition of favorable outcomes should include transition in the Modified Rankin score rather than MRS dichotomized as 0/1 or 0/1/2 because patients with transition in MRS scores have improvement in ADL, increased higher level of functioning and higher utility for health state.