Cross-Cultural Adaptation and Validation of the Korean Version of the EQ-5D in Patients with Rheumatic Diseases / 대한류마티스학회지

ABSTRACT

OBJECTIVE: This study is to determine the cross-cultural adaptation and validation of the Korean version of the EQ-5D (KEQ-5D) in various rheumatic patients. METHODS: We performed translation, backward translation and cognitive debriefing by the guidelines of the EuroQol group. The validity was evaluated by using the KEQ-5D, Korean Short- Form 36 (KSF-36) and disease-specific measures on 508 out-patients with ankylosing spondylitis, fibromyalgia syndrome, rheumatoid arthritis, osteoarthritis or systemic lupus erythematosus. Construct validity were evaluated by testing a-priori hypotheses of the association between the KEQ-5D and other measures. For the verification of reliability, we gave the same questionnaires twice to another 57 patients 1-week apart, and intra-class correlations and Kappa statistics were estimated. To test responsiveness, 60 patients with RA repeated the KEQ-5D at 12-week intervals within the context of 12-week clinical trials of a TNF blocker, and we calculated the t-test, effect size and standardized response mean RESULTS: There were no major modifications on the cross-cultural adaptation. The relationships between the KEQ-5D and the generic or disease-specific measures were observed to be as we expected previously in a-priori hypotheseshigher KEQ-5Dindex and KEQ-5DVAS scores were correlated with generic or disease-specific measures on the better health status, and groups with a better functional class showed higher KEQ-5D scores. The intra-class correlations of the KEQ-5Dindex and KEQ-5DVAS were 0.751 and 0.767, respectively, and Kappa statistics for agreement ranged from 0.455 to 0.772 across five dimensions. The standardized response means of KEQ-5Dindex and KEQ-5DVAS were 0.649 and 0.410. CONCLUSION: The KEQ-5D had good validity and sensitivity in several rheumatic conditions. Also, its reliability and responsiveness were moderate to good.