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Abstract

Introduction: The World Federation of Neurological Surgeons (WFNS) Scale and Hunt & Hess Grade rely only on clinical presentation to predict mortality following aneurysmal subarachnoid hemorrhage (aSAH). The proposed SAH score incorporates a combination of admission factors that impact mortality following aSAH. Hypothesis: We hypothesize that SAH score improves accuracy of mortality prediction in comparison to WFNS scale and Hunt & Hess Grade. Methods: Prospectively collected data of aSAH patients admitted to our institution between 1991-2009 were reviewed. We analyzed factors that impacted in-hospital SAH mortality following multiple logistic regression analysis. Scores were ‘weighted’ based on relative risk of mortality following stratification of each of these variables. GCS was subdivided into subgroups of 3-4, 5-8, 9-13 and 14-15; age was also split into 4 subgroups: 18-49, 50-69, 70-79 and >80. Medical co-morbidities were subdivided into none, 1 or >/=2 based on co-morbidities derived either from Charlson index or other factors (hypertension, cocaine) known to impact SAH outcomes, only if they were associated with increased mortality on univariate analysis. Results: 1134 patients were included; all-cause SAH hospital mortality was 18.3%. Admission GCS, age and medical co-morbidities significantly impacted mortality following multivariate analysis (P< 0.05). Association with mortality based on GCS was 7%(14-15; score 0), 18%(9-13; score 1), 40%(5-8; score 2) and 65%(3-4; score 4). Mortality based on age was 13%(18-49; score 0), 18%(50-69; score 1), 34% (70-79; score 2) and 46% (>80; score 3). Relationship of co-morbidities and mortality was 9%(none; score 0), 17%(one; score 1) and 32%(two/more; score 2). Summated Scores ranged from 0-8 with increasing mortality at higher scores (0=2%/ 1=6%/ 2=8%/ 3=13%/ 4=30%/ 5=54%/ 6=80%/ 7=89%/ 8=100%). PPV for scores in the range 7-8 was 90%; 6-8 was 84%. NPV for range 0-2 was 94% and 0-3 was 91%. AUC for SAH score was 0.822 (good accuracy), which was superior to WFNS (AUC 0.777, fair accuracy) and Hunt & Hess Grade (AUC 0.771, fair accuracy). Conclusions: The SAH score is a more accurate model than the WFNS scale and Hunt & Hess Grade in predicting mortality following SAH.