Validation in the Cross-Cultural Adaptation of the Korean Version of the Oswestry Disability Index

Disability questionnaires are used for clinical assessment, outcome measurement, and research methodology. Any disability measurement must be adapted culturally for comparability of data, when the patients, who are measured, use different languages. This study aimed to conduct cross-cultural adaptation in translating the original (English) version of the Oswestry Disability Index (ODI) into Korean, and then to assess the reliability of the Korean versions of the Oswestry Disability Index (KODI). We used methodology to obtain semantic, idiomatic, experimental, and conceptual equivalences for the process of cross-cultural adaptation. The KODI were tested in 116 patients with chronic low back pain. The internal consistency and reliability for the KODI reached 0.9168 (Cronbach's alpha). The test-retest reliability was assessed with 32 patients (who were not included in the assessment of Cronbach's alpha) over a time interval of 4 days. Test-retest correlation reliability was 0.9332. The entire process and the results of this study were reported to the developer (Dr. Fairbank JC), who appraised the KODI. There is little evidence of differential item functioning in KODI. The results suggest that the KODI is internally consistent and reliable. Therefore, the KODI can be recommended as a low back pain assessment tool in Korea.