Agreement between 30-day and 90-day modified Rankin Scale score and utility-weighted modified Rankin Scale score in acute intracerebral hemorrhage: An analysis of ATACH-2 trial data

Abstract

The relationship between 30- and 90-day modified Rankin Scale (mRS) scores in intracerebral hemorrhage (ICH) patients was evaluated. This post hoc cohort analysis of the ATACH-2 trial included patients with acute ICH who were alive at 30 days and who had mRS scores reported at 30 and 90 days. The mRS score was then converted to a utility (EuroQol-5 Dimension-3 Level [EQ-5D-3L])-weighted mRS score. After adjustment of 30-day mRS score for key covariates using multivariable ordinal regression, the relationship between 30-day and observed 90-day functional outcome was assessed via absolute difference in the utility-weighted version. Of the 1000 trial subjects, 898 met inclusion criteria. This low-moderate severity ICH cohort had a median baseline GCS score of 15 and median hematoma volume of 9.7 mL. Observed 30-day mRS had the largest association with observed 90-day values (χ² = 302.9, p < 0.0001). Patients generally either maintained the same mRS scores between 30 and 90 days (48 %) or experienced a 1-point (32 %) or 2-point (10 %) improvement by 90 days. The mean ± standard deviation (SD) EQ-5D-3L at 90 days was 0.67 ± 0.26. Following adjustment, the mean absolute difference between predicted and observed utility-weighted 90-day mRS scores was 0.006 ± 0.13 points and less than the estimated minimal clinically important difference of 0.13 points. The difference in average utility-weighted mRS scores at 30 and 90 days was not clinically relevant, suggesting 30-day score may be a reasonable proxy for 90-day values in patients with ICH when 90-day values are not available.

Keywords: Agreement; Cerebral Hemorrhage; Health Utility; Hemorrhagic Stroke; Recovery of Function; modified Rankin Scale.