Baseline NIH Stroke Scale score strongly predicts outcome after stroke: A report of the Trial of Org 10172 in Acute Stroke Treatment (TOAST)

Abstract

Objective: To compare the baseline National Institutes of Health Stroke Scale (NIHSS) score and the Trial of Org 10172 in Acute Stroke Treatment (TOAST) stroke subtype as predictors of outcomes at 7 days and 3 months after ischemic stroke. Methods: Using data collected from 1,281 patients enrolled in a clinical trial, subtype of stroke was categorized using the TOAST classification, and neurologic impairment at baseline was quantified using the NIHSS. Outcomes were assessed at 7 days and 3 months using the Barthel Index (BI) and the Glasgow Outcome Scale (GOS). An outcome was rated as excellent if the GOS score was I and the BI was 19 or 20 (scale of 0 to 20). Analyses were adjusted for age, sex, race, and history of previous stroke. Results: The baseline NIHSS score strongly predicted outcome, with one additional point on the NIHSS decreasing the likelihood of excellent outcomes at 7 days by 24% and at 3 months by 17%. At 3 months, excellent outcomes were noted in 46% of patients with NIHSS scores of 7 to 10 and in 23% of patients with scores of 11 to 15. After multivariate adjustment, lacunar stroke had an odds ratio of 3.1 (95% CI, 1.5 to 6 4) for an excellent outcome at 3 months. Conclusions: The NIHSS score strongly predicts the likelihood of a patient's recovery after stroke. A score of ≥16 forecasts a high probability of death or severe disability whereas a score of ≤6 forecasts a good recovery. Only the TOAST subtype of lacunar stroke predicts outcomes independent of the NIHSS score.