Study on reliability and validity of the clinical neurologic deficit scale in patients with stroke

Abstract

Objective To study the reliability and validity of the clinical neurologic deficit scale in evaluating stroke patients. Methods A total of 222 inpatients with acute stroke onset were included in the study. They were assessed when admitted, at the 14th and 90th day of hospitalization by different physicians using the clinical neurologic deficit scale. Intrarater and interrater reliability were determined using Kappa correlation. The split-half rehability and internal consistency were evaluated using Cranbach's a coefficient. Concurrent validity and the predictive validity were determined by spearman rank correlation coefficients. Construct validity was assessed by the factor analysis and the construct validity of the scale was measured according to the classifications of the Oxfordshire Community Stroke Project ischemic stroke subtypes in the patients with cerebral infarction. Results The scores of intrarater reliability in all items were higher than 0.6, the score of interrater reliability in the item walking was 0.542, the split-half reliability and the internal consistency were good as demonstrated by the score of 0.911 and 0.886 respectively, and assessment of reliability of different methods showed that strength in upper limb and strength in hand, were poor as shown by the score of 0.393 and 0.386 respectively. The scale is highly correlated with the NIHSS ( both P=0.000) in both total and subtypes of stroke patients according to the classifications of the Oxfordshire Community Stroke Project by concurrent validity analysis. There was a high correlation between the scores of the scale and Barthel Index and the modified Rankin scales at the 90th day of hospitalization (both P=0.000). Conclusions The clinical neurologic deficit scale has a good internal consistency. There is concurrent validity between the scale and the NIHSS and could predict stroke outcome. Factor analysis of the scale displays the best construct validity in the patients with partial anterior circulation infarction, and could be used to evaluate the focus of vertebrobasilar artery despite its insensitivity. Key words: Stroke; Severity of illness index; Prognosis