Validity and Reliability of Retrospective NIH Stroke Scale Assessment for Initial Stroke Severity

J Korean Neurol Assoc > Volume 24(1); 2006 > Article

Journal of the Korean Neurological Association 2006;24(1): 14-20.

NIH Stroke Scale을 이용한 초기 뇌졸중 중증도에 대한 후향적 평가의 타당성

윤성상, 부선희 박기정 장혜정a 권영대b

경희대학교 의과대학 신경과학교실, 경희대학교 경영대학 의료경영학전공a, 성균관대학교 의과대학 사회의학교실b

Validity and Reliability of Retrospective NIH Stroke Scale Assessment for Initial Stroke Severity

Sung Sang Yoon

Department of Neurology, Kyung Hee University College of Medicine, Seoul; Department of Health Services Management, Kyung Hee University College of Business Administrationa, Seoul; Department of Social and Preventive Medicine, Sungkyunkwan University School of Medicineb, Seoul, Korea

Abstract

Background: The retrospective severity scoring system of NIHSS for acute stroke patients was found to be valid and reliable by using patients' medical records in studies abroad. However, in Korea, medical records are often summarized and contain missing information which makes it difficult to conduct a restropective outcome study. The purpose of this research was to evaluate the validity and reliability of the retrospective NIHSS scoring system according to patients' medical records with written clinical histories and physical admission notes.
Methods: An algorithm for the retrospective NIHSS scoring system was developed and applied to 75 patients with acute ischemic stroke. Missing data on physical examination results were scored as normal. One neurologist who was blinded to this study measured the NIHSS score prospectively on the initial patient examination. After the patient's discharge, two other neurologists, blinded to the patient's clinical condition, evaluated the NIHSS score independently based on the information collected from the patient's physical admission notes. The criterion-related validity was evaluated by the Pearson Correlation Coefficient, and the measure of agreement between two raters was evaluated by the Kappa Statistic.
Results: The criterion-related validities of the retrospective NIHSS scoring system were high in the total and each itemized scores, except for the items of LOC command, limb ataxia, dysarthria, and neglect. The interrater reliabilities were also high except for the items of LOC command, limb ataxia, and dysarthria.
Conclusions: The retrospective NIHSS scoring algorithm was found to be a reliable and unbiased tool even when some physical examination elements are missing from the written medical records.