[MEASURING THE FUNCTIONAL IMPAIRMENT OF THE LUMBAR SPINE]

The purpose of our study was to outline the Hungarian validation process of the Oswestry Disability Index, the Quebec Back Pain Disability Scale, the Roland-Morris Disability Questionnaire and the Core Outcome Measurement Index, as well as to draw up recommendations regarding their future applications.

The Hungarian versions were created after a cultural and linguistic adaptation. Next to the above-mentioned questionnaires, the questionnaire booklet used for validation also contained the WHOQoL-BREF general quality of life questionnaire and a pain measuring Visual Analog Scale. The data of low-back pain patients were registered twice in two weeks. We determined the internal homogeneity (Cronbach alpha), reproducibility, standard error of measurement and the minimal detectable change of the questionnaires. Patients were assigned into different two subgroups (surgical / non-surgical, with/without affection of nerve roots) and differences between the subgroups were examined with the help of the questionnaires. We determined the physical subscale of the WHOQoL-BREF and the correlation between the pain and the studied questionnaires.

The value of Cronbach alpha was between 0.85 and 0.95. All four questionnaires showed significant differences (p<0.001) between the subgroups. The correlation studies brought strong and significant results (p<0.001, r>0.5) in every case. The values of reproducibility were between 0.93-0.92. The results of standard measurement error: 4.8 (Oswestry), 5.2 (Quebec), 1.6 (Roland-Morris), 0.59 (Core Index). The minimal detectable change was 13; 14; 4, and 2 points, respectively.

The Hungarian versions of all four questionnaires are valid. They can be applied with scientific certainty to measure low back pain patients. From the studied questionnaires, we especially recommend the wide-raging application of the Oswestry Disability Index and the Core Outcome Measurement Index based on their psychometric and application features.