The Itemized NIHSS Scores Are Associated With Discharge Disposition in Patients With Minor Stroke

Background and purpose: The ability of the National Institutes of Health Stroke Scale (NIHSS) score to predict functional outcome in minor stroke is controversial. In this study, we examined the association of itemized NIHSS score with discharge outcome. Methods: We included all patients with final diagnosis of stroke with an NIHSS score of 0 to 5 untreated with thrombolysis enrolled in the "Stroke Warning Information and Faster Treatment'' trial. Individual components of the NIHSS score were the primary predictors. Poor outcome was defined as not being discharged home. Logistic regression was used to identify predictors of outcome. Results: A total of 861 patients met the inclusion criteria; 162 (19%) were not discharged home. In multivariable regression, predictors of discharge other than home were age (odds ratio [ OR] = 1.02 per year increase, P < .001) and total NIHSS score (OR per unit increase in the NIHSS = 1.51, P < .001). Motor (OR = 2.32, P < .001), level of consciousness (LOC; OR = 6.62, P = .004), and ataxia (OR = 3.10, P < .001) were also associated with not being discharged home. Motor (area under the curve [AUC] 0.623) appeared to be more predictive of poor outcome than ataxia (AUC 0.569) and LOC (AUC 0.517). The total NIHSS had a fair correlation with discharge outcome (AUC 0.683). Conclusion: Total and itemized NIHSS components have a fair correlation with outcome in minor stroke highlighting the importance of other measures of stroke severity for clinical trials.