Utility-weighted modified rankin scale scores in patients with ischemic stroke: a multicenter observational study

This study assessed patient-reported health-related quality of life (QOL) in a real-world cohort of patients with ischemic stroke and estimated utility-weighted modified Rankin Scale (UW-mRS) scores.

We included 1452 patients with ischemic stroke (median age: 75 [67-83] years; 41.0% female) from a multicenter hospital-based stroke registry in Japan. QOL was evaluated using the EQ-5D-5L with Japanese-specific utility values. Both EQ-5D utility values and mRS scores were assessed after completion of acute treatment. UW-mRS scores were estimated using ordinary least squares (OLS) and Tobit regression models.

The mean (SD) EQ-5D utility value was 0.68 (0.27). Higher mRS scores were associated with greater severity and frequency of problems across EQ-5D domains, with a marked decline observed between mRS scores 3 and 4. UW-mRS scores estimated by OLS were: mRS 0: 0.90, mRS 1: 0.85, mRS 2: 0.74, mRS 3: 0.62, mRS 4: 0.41, and mRS 5: 0.28. The Tobit model yielded slightly higher values for mRS 1-3. UW-mRS estimates remained largely consistent across other regression models (fractional logit/probit, beta regression, and two-part models). However, UW-mRS values differed between early (≤ 14 days from onset) and late (> 14 days) assessments and varied considerably when utility values were calculated using tariffs from other countries or with the EQ-5D-3L crosswalk.

In this real-world, consecutive cohort of hospitalized Japanese patients with ischemic stroke, utility values were estimated using the EQ-5D-5L, and the UW-mRS was characterized as a practical tool for deriving utility values from mRS scores.