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Abstract: The use of grading states to predict clinical outcomes following aneurysmal subarachnoid hemorrhage
(aSAH) is commonplace. In recent times management of aSAH patients has developed such that surgical intervention is taking place earlier in the course of the illness. Given the complex and multifactoral clinical picture of these patients, there is an increased impetus to examine and reevaluate the relative merits and predictive characteristics of grading scales. The measurement characteristics and predictive power of the following instruments were reviewed: Fisher Scale (FS), Glasgow Coma Scale (GCS), Glasgow Outcome Score (GOS), Hunt and Hess (HH) Scale, Karnovsky Performance Scale (KPS), and the World Federation of Neurological Surgeons (WFNS) Scale. No uniformly conclusive findings were found when the HH Scale, GCS, and WFNS Scale were used to predict clinical outcomes. No instrument consistently outperformed any other across age or severity. Contradictory findings were reported. Difficulties were encountered in comparing instruments because of administration, scoring schemes, timing of assessments, and psychometric properties, such as interrater reliability. Reports on newly developed instruments often lacked the replication data necessary to effectively compare measures currently in use. The timing of measurements and the use of serial measures emerged as important factors in the prediction of clinical outcomes. Assessments taken close to the time of surgical intervention were found to have superior predictive abilities.
Most prevalent in the 40- to 60-year age range, aneurysmal subarachnoid hemorrhage (aSAH) is associated with significant morbidity and mortality. Risk increases with age (King, 1997). Incidence for women is generally higher than that in men and higher in African American individuals (Davis, 1994; Ingall & Wiebers, 1993). Grading scales have been used to predict clinical outcomes of patients. These scales include the Fisher Scale (FS), Glasgow Coma Scale (GCS), Glasgow Outcome Score (GOS), Hunt and Hess (HH) Scale, and the Karnovsky Performance Scale (KPS). Historically, these scales were used when the surgical management of aneurysms was performed later in the illness trajectory, usually after complications from vasospasm or rebleeding were thought to have passed (Chiang, Claus, & Awad, 2000). Treatment today, however, is likely to occur much earlier in the course of illness. Given this change, it is timely to review the measurement tools frequently used to predict clinical outcomes. Reliable and accurate...