Cross-cultural adaptation and validation of the Korean version of the neck disability index.
METHODS
Validation of a translated, culturally adapted questionnaire.


OBJECTIVE
The purpose of this study is to translate and culturally adapt the Neck Disability Index (NDI) and to validate the use of the derived version in Korean patient.


BACKGROUND
Although several valid measures exist for measurement of neck pain and functional impairment, these measures have yet been validated in Korean version.


METHODS
The NDI was linguistically translated into Korean, and prefinal version was assessed and modified by a pilot study. The reliability and validity of the derived Korean version was examined in 78 patients with degenerative cervical spine disease. Test-retest reliability, internal consistency, and construct validity were investigated by comparing Visual Analogue Scale (VAS) and Short Form Health Survey (SF-36) scores.


RESULTS
Factor analysis of Korean NDI extracted 2 factors with eigenvalues >1. The intraclass-correlation coefficient of test-retest reliability was 0.93. Reliability, estimated by internal consistency, had a Cronbach alpha value of 0.82. The correlation between NDI and VAS scores was r = 0.49, and the correlation between NDI and SF-36 scores was r = -0.44. The physical health component score of SF-36 was highly correlated with NDI, and the correlation between VAS scores and the mental health component scores of SF-36 was high.


CONCLUSIONS
The derived Korean version of the NDI was found to be a reliable and valid instrument for measuring disability in Korean patients with cervical problems. The authors recommend its use in future Korean clinical studies.
Song
Kyung-Jin
KJ
Department of Orthopedic Surgery, School of Medicine, Research Institute of Clinical Medicine, Chonbuk National University Hospital, Jeonju, Korea.
Choi
Byung-Wan
BW
Choi
Byung-Ryeul
BR
Seo
Gyeu-Beom
GB
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D006306:Health Surveys; D006801:Humans; D007723:Korea; D007802:Language; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000503:physiopathology*; D010865:Pilot Projects; D015203:Reproducibility of Results