Proposal of a Grading System for Predicting Discharge Mortality and Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND: Several outcome prediction systems have been developed to evaluate aneurysmal subarachnoid hemorrhage (aSAH). However, they can be difficult to use and can contain subjective elements. We sought to identify the predictors of aSAH outcomes at discharge to provide an accurate and reliable scoring system. METHODS: A retrospective cohort study of patients with aSAH at an academic institution from 2007 to 2016 was conducted. The primary outcome measure was the modified Rankin scale (mRS) score at discharge, with mRS scores of 0-2 considered favorable and mRS scores of 3-6 considered unfavorable. Factors significant on multivariate regression were used to develop a scale, which was compared with other established grading systems using receiver operating characteristic curves. RESULTS: We identified 279 patients with aSAH, 37.3% of whom had unfavorable outcomes. The proposed scale assigns 2 points for postresuscitation Glasgow coma scale score of <= 8, 1 point for age >= 70 years, 1 for antiplatelet therapy on admission, and 1 for SAH thickness of >= 10 mm, with a total score of 0-5. The proposed, Subarachnoid Hemorrhage International Trialists, and Hunt and Hess scales had similar areas under the curve (85.2%, 84.8%, and 80.6%, respectively; P > 0.05) but were significantly better than the World Federation of Neurological Surgeons (78.5%; P = 0.001) and modified Fisher (60.8%; P < 0.001) scales. CONCLUSION: We propose a grading scale to predict discharge mortality and functional outcomes in patients with aSAH. The proposed scale outperformed most other outcome prediction scales. The proposed scale contains objective elements, is easy to apply by memory, and can be a useful and effective measure to predict aSAH outcomes.