[Evaluation of 2 questionnaires with reference to their suitability for self-evaluation of patients with gonarthrosis. A contribution to quality assurance in rheumatology].

Questionnaires are useful instruments to evaluate disability and handicap in patients suffering from rheumatic diseases. Most of the used questionnaires require a time consuming interview with the attending physician or medical health personnel. Two (Larson and Lequesne) well established questionnaires are available for osteoarthritis(OA)-patients. Since it would be desirable to have reliable patients self reporting questionnaires, we have tested the utility and validity of these questionnaires by comparing the results of patients self reports with the results obtained by medical health personnel (4 occupational- and physiotherapists) in the same patients (n = 52). The analysis of the questionnaires revealed that results obtained by the Larson technique gave very different (p < 0.01) global and detail scores as assessed by patients or medical staff. This difference of assessments was not influenced by the stage of arthrosis as defined by x-ray. The Lequesne questionnaires gave essentially similar results, with a significant difference between assessment of disease severity by patients in comparison to results obtained by medical staff. The results obtained by the 4 members of the medical staff did not differ significantly from each other. From our study it is concluded that neither the Larson nor the Lequesne questionnaire can be recommended for scientific use as a reliable patients self reporting evaluation of disease severity in osteoarthritis.