Reliability and validity study on the Hungarian versions of the oswestry disability index and the Quebec back pain disability scale.
Valasek T., Varga PP., Szövérfi Z., Kümin M., Fairbank J., Lazary A.
PURPOSE: Patient-reported outcome measurements (PROMs) are widely used in spine care. The development of reliable and valid National versions of spine-related disability questionnaires is strongly recommended from both the clinical and scientific points-of-view. The aims of this study were to adapt and validate the Oswestry Disability Index (ODI) and the Quebec back pain disability scale (QDS) for use with the Hungarian language. METHODS: After translating and culturally adapting the ODI and QDS, 133 patients with lumbar degenerative spinal disorder filled in the questionnaire booklet twice within 2 weeks. Subjects completed the Hungarian versions of the two PROMs as well as the WHOQoL-BREF validated as a general life quality questionnaire and Visual Analogue Scale of pain. Internal consistency, reliability and construct validity of the questionnaires were determined, as were the standard error of measurement (SEM) and minimal detectable change (MDC) scores. RESULTS: The Hungarian ODI consisted of one factor that showed good internal consistency (Cronbach-α 0.890). The QDS showed a four-factor structure with Cronbach-α values between 0.788 and 0.917. No significant floor or ceiling effects were observed. The test-retest analysis showed excellent reliability of the Hungarian ODI and QDS. The intraclass correlation coefficients (ICC) were 0.927 and 0.923, respectively. SEM values of 4.8 and 5.2 resulted in a MDC of 13 and 14 points in the Hungarian ODI and QDS, respectively. The correlation coefficient (r) between pain and ODI was 0.680 (p < 0.001) and the correlation between the ODI and the physical subscale of WHOQoL was also very good (r = -0.705, p < 0.001). The QDS total score and its four subscales correlated significantly with pain and with the physical subscale of WHOQoL (r > 0.4, p < 0.001). The level of disability measured by the Hungarian ODI and QDS was significantly higher in the surgical subgroup than in non-surgically treated patients (p < 0.001). CONCLUSIONS: Translation and cultural adaptation of the ODI and QDS were successful. Hungarian versions of the ODI and QDS proved to be reliable, valid PROMs confirming that they can be used in future clinical and scientific work with Hungarian-speaking spine patients.