Patient Relevance of the Modified Rankin Scale in Subarachnoid Hemorrhage Research: An International Cross-sectional Survey

Background And Objectives: There is significant heterogeneity in the reporting of outcome measures in aneurysmal subarachnoid hemorrhage (aSAH) research. The modified Rankin scale (mRS) is the most commonly reported functional outcome measure. The mRS focuses on physical disability; however, many aSAH survivors experience sequalae in other domains, and the mRS may therefore not capture outcomes important to aSAH survivors. The objective of this study was to assess the clinical relevance of the mRS as a research outcome measure to people with lived aSAH experience.

Methods: We conducted an international cross-sectional survey of 355 aSAH survivors, family members, and caregivers to evaluate patient-perceived outcomes in relation to the mRS. The mRS was assessed using a previously validated web-based tool.

Results: Response rate was 60%; respondents from 7 continents were composed of 86% aSAH survivors and 14% family members/caregivers. Agreement between self-assessed outcome and the mRS was poor (Kappa 0.26 [CI 0.14-0.39]). Of the 172 respondents who self-assessed as having had a good aSAH outcome, 122 (71%) had a score of 0-2 on the mRS. Approximately 19% of respondents with a good outcome, based on a measured mRS score of 0-2, self-assessed as having had a poor aSAH outcome. When the mRS score was dichotomized as 0-3 corresponding to a good outcome, agreement between the score and self-assessed outcome remained poor with a Kappa score of 0.40 (CI 0.20-0.60). Approximately 30% of respondents believed that the mRS should not be used as an outcome measure in future aSAH trials.

Discussion: The findings suggest that there is poor agreement between aSAH survivors' self-assessed outcome, their actual mRS score, and the dichotomization of the mRS score into good/poor outcomes. Patient-centered and patient-informed outcome measurement tools are needed to guide the aSAH research agenda.