Abstract 188: Differences in Quality of Life Across Modified Rankin Scale Categories in IMS-3

Abstract

Background: Modified Rankin Scale (mRS) score 0-2 is frequently used as a definition of good outcome in ischemic stroke trials. Patients with mRS 3 are frequently grouped with mRS 4-6 as having poor outcome yet there is limited data on health-related quality of life (QOL) across mRS scores. Objective: Determine QOL and levels of disability across mRS scores and to specifically compare mRS 2 and 3 outcome categories. Methods: A secondary analysis of the Interventional Management of Stroke 3 (IMS3) trial was performed. Patients with documented mRS, degree of disability assessed by Barthel Index (BI) and patient-completed EQ5D-3L quality of life questionnaires at 3 months after stroke were included. EQ5D index was calculated using utility weights published for the US population. Median and mean BI and EQ5D were compared across mRS categories. Multiple pairwise comparisons were performed and Bonferroni corrected p-values were used. No imputations were performed. Results: 423 patients were included (mean age 64±13 years, median ASPECTS 8 [IQR 6-10], median baseline NIHSS 16 [IQR 12-19], mean BI 84.1±25.3 and mean EQ5D index 0.727±0.24. Overall, there were inverse correlations between mRS and BI (Rho=-0.78, p<0.001) and between mRS and EQ5D (Rho=-0.69, p<0.001). While significant differences in BI were observed across several mRS categories including 1 vs 2, 2 vs 3 and 3 vs 4 (Fig A), there was no difference in QOL between mRS 2 (N=82) and 3 (N=88) categories (Fig B). Based on BI and EQ5D indices, mRS 3 had greater similarity to mRS 2 than to mRS 4 (Fig C). Conclusion: Health-related QOL is similar in patients who achieve mRS of 2 and 3 despite differences in degree of disability. If preservation of quality of life is the ultimate goal of acute stroke therapies, our results question the commonly used mRS 0-2 cut point used to dichotomize stroke outcomes.