Cross-cultural adaptation and cross-sectional psychometric testing in a convenience sample of patients with low back pain.
To translate and culturally adapt the Oswestry Disability Index version 2.1 (ODI 2.1) into a Mandarin Chinese version and to assess its reliability and validity.
The Chinese ODI 2.1 has not been developed and validated.
The ODI 2.1 was translated and culturally adapted to the Chinese version. The validity of the translated Chinese version was assessed by examining the relationship between the ODI and other well-known measures. Test-retest reliability was examined in 52 of these patients, who completed a second questionnaire within 1 week.
Internal consistency of the ODI 2.1 was excellent with Cronbach's alpha = 0.903. The intraclass correlation coefficient of test-retest reliability was 0.89. The minimal detectable change was 12.8. The convergent validity of the Chinese ODI is supported by its high correlation with other physical functional status measures (Roland Morris Disability Questionnaire and SF-36 physical functioning subscale, r = 0.76 and -0.75, respectively), and moderate correlation with other measures (Visual Analogue Scale, r = 0.68) and certain SF-36 subscales (role-physical, bodily pain, and social functioning, r range: -0.49 to -0.57). As expected, the ODI was least correlated with nonfunctional measures (SF-36 mental subscale and role-emotional subscale, r = -0.25 and -0.33, respectively).
The results of this study indicate that the Chinese version of the ODI 2.1 is a reliable and valid instrument for the measurement of functional status in patients with low back pain.