Comparative responsiveness of the EuroQol-5D and Short Form 6D to improvement in patients with rheumatoid arthritis treated with tumor necrosis factor blockers: results of the Dutch Rheumatoid Arthritis Monitoring registry.

OBJECTIVE: For cost-utility analyses of health technologies, utilities are commonly measured with the EuroQol-5D (EQ-5D) or the Short Form 6D (SF-6D). Although most studies in rheumatoid arthritis (RA) found the SF-6D to be more responsive than the EQ-5D, evidence is not convincing. The aim of this study was to compare the responsiveness of the EQ-5D and SF-6D to improvement in RA patients treated with tumor necrosis factor (TNF) blockers.
METHODS: Data from 278 RA patients included in the Dutch Rheumatoid Arthritis Monitoring registry were used. Internal responsiveness over 1 year was evaluated by using standardized response means (SRMs). External responsiveness was evaluated by using receiver operating characteristic curves based on perceived health change (self-reported health transition item Short Form 36) and change in disease activity (European League Against Rheumatism response criteria based on the Disease Activity Score in 28 joints).
RESULTS: The scores of the EQ-5D and SF-6D changed moderately over 1 year (SRMs 0.50 and 0.67, respectively). The SF-6D was significantly more responsive to treatment than the EQ-5D. The EQ-5D and SF-6D were moderately able to correctly classify patients according to health transition (areas under the curve [AUCs] 0.67 and 0.72, respectively) and change in disease activity (AUCs 0.71 and 0.65, respectively).
CONCLUSION: The EQ-5D and SF-6D were only moderately responsive to improvement in RA patients treated with TNF blockers. Overall, the SF-6D was more responsive than the EQ-5D.