Quebec Back Pain Disability Scale, Low Back Outcome Score and revised Oswestry low back pain disability scale for patients with low back pain due to degenerative disc disease: evaluation of Polish versions.

STUDY
DESIGN: Evaluation and comparison of translated and culturally adapted self-reported measurements.
OBJECTIVE: The aim of this prospective study was to cross-culturally adapt the Polish versions of Revised Oswestry Disability Index (RODI-PL), Quebec Back Pain Disability Scale (QDS-PL), and the Low Back Outcome Score (LBOS-PL). SUMMARY OF BACKGROUND DATA: The application of instruments in English, which have undergone translation must be subjected to validation studies. Such studies are necessary above all for instruments that have been adapted to establish their value and usefulness in studies of patient populations where English is not the native language.
METHODS: The translation was carried out according to International Quality of Life Association (IQOLA) Project and consisted of the following stages: translation, synthesis of the translations, back translation, expert committee, and testing of the prefinal versions of questionnaires. Eighty-five consecutive patients with low back pain due to spinal disc herniation and degenerative changes completed the QDS-PL, RODI-PL, LBOS-PL, and a Visual Analogue Scale twice within 2-day intervals. Mean duration of LBP was 45.9 months SD 55.5. The evaluation of degenerative changes in the lumbar region was carried out according to the Modic scale. Twenty-nine patients were categorized at type I, 4 patients were registered as type II, and 52 patients were type III.
RESULTS: Cronbach α values for the LBOS-PL equaled 0.77, for the RODI-PL 0.85, and 0.95 for the QDS-PL. Item-total correlation confirmed that all scales are internally consistent. Test-retest reliability was excellent for RODI-PL and QDS-PL, but poor for LBOS-PL (0.88, 0.93, and 0.34, respectively). All questionnaires were significantly intercorrelated. We identified the strongest correlation between QDS-PL and RODI-PL (0.823, P < 0.001). The statistically significant correlation was identified between the QDS-PL and Modic Classification (rS = 0.226 P = 0.038).
CONCLUSION: QBPDS-PL and RODI-PL are reliable and valid. Furthermore, investigation of the psychometric properties of the LBOS-PL in different spinal conditions is required. There is a relation between the results of the QDS-PL, and different levels of advancement in degenerative disease of the lumbar spine, according to the Modic Classification.