Validation of an aneurysmal subarachnoid hemorrhage grading scale in 1532 consecutive patients

The two most commonly used aneurysmal subarachnoid hemorrhage grading scales are the Hunt and Hess and World Federation of Neurological Societies scales. Neither has achieved universal acceptance, however, owing to concerns regarding either subjectivity or lack of correlation with outcomes, respectively. A grading scale based entirely on the Glasgow Coma Scale (GCS) was recently proposed. We have prospectively evaluated the GCS grading system and compared it with the Hunt and Hess and World Federation of Neurological Societies scales for predictive accuracy.

Data from 1532 consecutive patients with intracranial aneurysms admitted to our institution between January 1991 and June 2005 were analyzed. The Glasgow Outcome Scale was the primary outcome measure. Mortality and length of stay were secondary measures. The scales were evaluated using simple and multivariable logistic and linear regression. Receiver operating characteristic curves were used to assess predictive accuracy for the Glasgow Outcome Scale. Prognostic factors were assessed with ordinal multivariable logistic regression.

The GCS grading system was most strongly associated with all outcome measures and was the strongest predictor of mortality and persistent vegetative state. Age, vasospasm, hydrocephalus, and intracranial hematoma were found to be significant prognostic elements.

The GCS grading system is more strongly associated with outcomes than either the Hunt and Hess or World Federation of Neurological Societies scales, and it is an equivalent to a slightly better predictor of Glasgow Outcome Scale outcomes. Its simplicity, proven inter-rater reliability, and wide level of familiarity among health care personnel render the GCS grading system a superior grading scale for aneurysmal subarachnoid hemorrhage severity, warranting its consideration for universal use.