Modified National Institutes of Health Stroke Scale can be estimated from medical records.
OBJECTIVE
The 15-item National Institutes of Health Stroke Scale (NIHSS) is a quantitative measure of stroke-related neurological deficit with established reliability and validity for use in clinical research. An abridged 11-item modified NIHSS (mNIHSS) has been described that simplifies or eliminates redundant and less reliable items. We aimed to determine whether the mNIHSS could be accurately abstracted from medical records to facilitate retrospective research.


METHODS
We selected 39 patient records for which NIHSS scores were formally measured. Handwritten notes from medical records were abstracted, and NIHSS item scores were estimated by 5 raters blinded to actual scores. Estimated scores were compared among raters and with actual measured scores.


RESULTS
Interrater reliability for total NIHSS on admission and discharge was excellent, with intraclass correlation coefficients (ICCs) of 0.85 and 0.79, respectively. However, ICCs for 2 items (facial palsy and dysarthria) were poor (<0.40). Interrater reliability for total mNIHSS was slightly greater, with ICCs of 0.87 and 0.89 on admission and discharge, respectively. None of the 11 mNIHSS items had poor reliability, 4 were moderate (ICC, 0.40 to 0.75), and 7 were excellent (ICC >0.75). Sixty-two percent of estimated total NIHSS scores were within 2 points of actual scores and 91% were within 5 points, whereas 70% of estimated total mNIHSS scores were within 2 points and 95% were within 5 points.


CONCLUSIONS
The mNIHSS can be estimated from medical records with a high degree of reliability and validity. In retrospective assessment of stroke severity, the mNIHSS performs better than the standard NIHSS and may be easier to use because it has fewer and simpler items.
Kasner
Scott E
SE
Department of Neurology, University of Pennsylvania Medical Center, Philadelphia 19104, USA. kasner@mail.med.upenn.edu
Cucchiara
Brett L
BL
McGarvey
Michael L
ML
Luciano
Jean M
JM
Liebeskind
David S
DS
Chalela
Julio A
JA
D006801:Humans; D008499:Medical Records / Q000706:statistics & numerical data*; D009316:National Institutes of Health (U.S.); D015588:Observer Variation; D017063:Outcome Assessment, Health Care; D010343:Patient Admission / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000145:classification* / Q000175:diagnosis* / Q000453:epidemiology; D014481:United States / Q000453:epidemiology