The Korean version of the Oswestry Disability Index (ODI) is the most widely used tool validated instrument for measuring and the level of disability associated with low back disorders. We wanted to validate use of the Korean version of the ODI in Korean farmers with low back pain.

The object of this study was to examine the reliability and validity of the Korean version of the ODI. The Korean version was tested on 53 farmers (62.3±10.3 years of age) with low back-related disorders. We investigated the Test-retest reliability, internal consistency, and construct validity of the ODI. The Test-retest reliability was assessed in 30 farmers within a time interval of approximately 14 to 18 days. Differences between the Korean version of the ODI and the Short Form 12 (SF-12), which includes 8 domains (general health, physical functioning, role-physical limitation, bodily pain, role-emotional limitation, mental health, vitality, social functioning) were analyzed for construct validity. The correlation of the Korean version of the ODI with the SF-12 was analyzed, as well.

The intra-class correlation coefficient of test-retest reliability was 0.854. Reliability estimated by the internal consistency reached a Cronbach's alpha of 0.879. The correlation between 7 domains of the SF-12 except for the mental health domain and the Korean version of the ODI was statistically significant (p<0.05). Four domains (general health, physical functioning, role-physical limitation, bodily pain) that measured physical status all showed high correlations (p<0.01), as did a domain that measured mental status (role-emotional limitation) (p<0.01).

The results showed that the Korean version of the ODI is a reliable and valid instrument to measure the level of disability in Korean farmers with low back-related disorders. The use of this instrument is recommended for future clinical trials in Korea.