Construct Validity and Responsiveness of EQ-5D-3L and EQ-5D-5L in Patients With Inflammatory Joint Disease

Construct Validity and Responsiveness of EQ-5D-3L and EQ-5D-5L in Patients With Inflammatory Joint Disease

The aim of this study is to compare the construct validity (convergent validity and known-groups validity) and responsiveness of EQ-5D-3L and EQ-5D-5L in patients with inflammatory joint disease. The study is based on prospectively collected data through the Swedish Rheumatology Quality Register (SRQ).

A detailed description of the study can be found in the uploaded document titled 'Study Protocol and Statistical Analysis Plan.'

Inclusion Criteria:

• Agreed to participate in the study
• ≥18 years at the time of the first measurement
• A diagnosis of rheumatoid arthritis (RA), polyarthritis, psoriatic arthritis (PsA), or ankylosing spondylitis (AS)
• Complete registration of responses in the EQ-5D-3L and EQ-5D-5L descriptive system at least at one time point (one visit)
• For patients with RA: At least one measurement with Disease Activity Score 28 (DAS28) reported in relation to the same visit as the EQ-5D was registered
• For patients with polyarthritis: At least one measurement with DAS28 reported in relation to the same visit as the EQ-5D was registered
• For patients with PsA: At least one measurement with DAS28 or Disease Activity in Psoriatic Arthritis (DAPSA) reported in relation to the same visit as the EQ-5D was registered
• For patients with AS: At least one measurement with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) or the Axial Spondyloarthritis Disease Activity Score (ASDAS) reported in relation to the same visit as the EQ-5D was registered