The reliability and validity assessment of western Ontario and McMaster university osteoarthritis index scale applied with Kashin-Beck disease

Objective To evaluate the applicability of western Ontario and McMaster university osteoarthritis index (WOMAC) on Kaschin-Beck disease (KBD). Methods Clinical degree I adult patients with KBD came from Yongshou and Linyou Counties in Shaanxi Province were investigated according to the historical diagnostic data andThe Diagnosis Standard of Kashin-Beck Disease (GB 16003-1995), exclusion of other chronic diseases. Reliability of WOMAC was measured by retest reliability, 1/2 coefficient and Cronbach'α reliability coefficient analysis; validity of the WOMAC was tested by the principal components, factor analysis and correlation analysis methods. Results Totally 200 adults patients with KBD were investigated, and 177 effective questionnaires were taken back (88.5%). Retest reliability was 0.754-0.853, 1/2 coefficient was 0.886-0.971, and Cronbach'α reliability coefficient was 0.878-0.956. In three dimensions of WOMAC scale extracted a common factor, the cumulative variance contribution rate was 81.238% through principal component factor. The pearson correlation coefficient between all items score of WOMAC and scale score and total score of WOMAC was more than 0.600. The differences of WOMAC score were not statistically significant in different ages, different grading of adult KBD patients (all P > 0.05). Conclusion WOMAC scale used in KBD has good validity and reliability, but has low degree of differentiation. Key words: Reliability; Validity; Kashin-Beck disease