Establishment of the Thai version of National Institute of Health Stroke Scale (NIHSS) and a Validation Study
Yongchai Nilanont MD*, Sucheera Phattharayuttawat PhD**, Pipat Chiewit MD***, Songkram Chotikanuchit MD*, Juljak Limsriwilai MD*, Lultrita Chalernpong MD*, Napaporn Yamkaew RN*, Niramol Lirathpong RN*, Pornpimol Anprasertporn MD*, Chulaluk Komoltri DrPH****, Naraporn Prayoonwiwat MD*, Niphon Poungvarin MD, FRCP, FRI*
Affiliation : * Division of Neurology, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. ** Department of Psychiatry, Siriraj Hospital, Mahidol University, Bangkok, Thailand. *** Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand. **** Department of Research development, Mahidol University, Bangkok, Thailand
Background : The National Institute of Health Stroke Scale (NIHSS) is a well validated stroke severity assess-
ment scale. The scale is used to assess neurological deficits, progression and degree of recovery in acute
stroke settings. To date, no Thai version exists.
Objective : This study aimed to adapt and validate a Thai version of the NIHSS (NIHSS-T).
Material and Method: A cross-cultural adaptation of the NIHSS was developed according to the methods
recommended by the International Quality of Life Assessment Project Group. Forward and backward
translations were performed. A final version of the NIHSS-T was validated against initial MRI infarction
volume and modified Rankin Scale (mRS) at 3 months in a consecutive series of acute stroke patients. The
patients were prospectively evaluated by 3 different types of health care providers: 2 stroke fellows, 2 internists,
and 2 stroke nurses. Mean NIHSS-T scores from all raters were used in the analysis.
Results : The study included 32 acute ischemic stroke patients with a mean age (+ SD) of 64.53 + 14.97 years
of age. Men comprised 71.9%. Mean NIHSS-T score (+ SD) was 7.49 + 7.02. Intra-observer reliability demon-
strated a high agreement with an intraclass correlation (ICC) of 0.98, 0.98, 0.96, 0.98, 0.90 and 0.98 for 2
stroke fellows, 2 internists and 2 stroke nurses respectively. Inter-observer reliability between 6 raters was
excellent, i.e.; ICC, 0.99 (0.98, 0.99). Spearman rank correlation coefficients between the initial NIHSS-T
score versus initial MRI lesion volume and mRS at 3 months were 0.53 and 0.69 with a p-value of 0.002 and <
0.001 respectively.
Conclusion : The Thai version of NIHSS is valid for assessing acute stroke severity. The scale is also reliable
when administered in a Thai-speaking setting by trained healthcare professionals.
Keywords : National Institute of Health Stroke Scale (NIHSS), Thai version, Stroke severity assessment, Neu- rological scales
