COMPARISON OF NEUROLOGICAL SCALES AND SCORING SYSTEMS FOR ACUTE STROKE PROGNOSIS

Background and Purpose Clinical trials routinely use stroke scales to compare baseline characteristics of treatment groups. It is unclear wh ich stroke scale provides the most prognostic information. This often leads to collection of multiple scales in clinical trials. We aimed to determine which of several commonly used scales best predicted outcom e. Methods A single observer scored consecutive admissions to an acute stroke unit on the National Institutes of Health Stroke Scale (NIHSS) , the Canadian Neurological Scale, and the Middle Cerebral Artery Neur ological Score. Guy's prognostic score was determined from clinical da ta. Outcome at 2, 3, 6, and 12 months was categorized as good (alive a t home) or poor (alive in care or dead). Predictive accuracy of the va riables was compared by receiver operating characteristic curves and s tepwise logistic regression. Results Of the 408 patients studied, 373 had confirmed acute stroke and completed follow-up. The three stroke r ating scales each predicted 3-month outcome with an accuracy of .79 or greater. The NIHSS provided the most prognostic information: sensitiv ity to poor outcome, .71 (95% confidence interval [CI], .64 to .79); s pecificity, .90 (95% CI, .86 to .94); and overall accuracy, .83 (95% C I, .79 to .87). Logistic regression showed that the NIHSS added signif icantly to the predictive value of all other scores. No score added us eful information to the NIHSS. A cut point of 13 on the NIHSS best pre dicted 3-month outcome.Conclusions Baseline NIHSS best predicts 3-mont h out come. The Canadian Neurological Scale and Middle Cerebral Artery Neurological Score also perform well. Baseline assessments in clinica l trials only need to include a single stroke rating scale.