Construct Validity and Responsiveness of EQ-5D-3L in Patients With Rheumatic Disease
NCT Number: NCT06568029
Status: RECRUITING
Study Type: OBSERVATIONAL
Conditions: Rheumatoid Arthritis|Polyarthritis|Psoriatic Arthritis|Ankylosing Spondylitis|Rheumatic Diseases
Interventions: OTHER: Questionnaire
Sponsor: Karolinska Institutet
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 10000
Study Design: Observational Model: |Time Perspective: p
Start Date: 2024-08-16
Completion Date: 2024-09
Locations: It is an observational study based on the The Swedish Rheumatology Quality Register, Stockholm, Sweden

Summary:
The aim of this study is to investigate the construct validity (convergent and known-groups) and responsiveness of EQ-5D-3L in patients with rheumatoid arthritis, polyarthritis, psoriatic arthritis, and ankylosing spondylitis. The study is based on retrospective registry data from the Swedish Rheumatology Registry (SRQ).

Primary Outcome Measures: Convergent validity, Convergent validity refers to how well the instrument under study (EQ-5D-3L and EQ VAS) correlates with other outcome measures (Fayers and Machin 2007). According to COSMIN guidelines, convergent validity should be assessed by formulating and testing hypotheses regarding the expected direction and magnitude of the correlation between the measurement being studied (EQ-5D-3L and EQ VAS) and other outcome measures measuring the same or similar constructs (Mokkink, Prinsen et al. 2019). The constructs measured by the other outcome measures should be clearly described (Mokkink, Prinsen et al. 2019). See hypotheses in document Study Protocol and Statistical Analysis Plan., One measurement per patient.The latest complete EQ-5D-3L and EQ VAS measurements per patient during the period 2008-2024 is used for the analysis.|Known-groups validity, Known-groups validity refers to how well the instrument can find differences between groups known to differ. Known-groups validity should be assessed by formulating and testing hypotheses regarding expected directions and magnitude of the differences between subgroups (Mokkink, Prinsen et al. 2019). See hypotheses in document Study Protocol and Statistical Analysis Plan., One measurement per patient. The latest complete EQ-5D-3L and EQ VAS measurements per patient during the period 2008-2024 is used for the analysis.|Responsiveness, Responsiveness refers to the ability of the instrument to capture change over time in the construct that is measured (Mokkink, Terwee et al. 2010). According to COSMIN guidelines, responsiveness can be assessed by comparing changes in EQ-5D-3L and EQ VAS, with changes in other outcome measures, similar to convergent validity explained above (Mokkink, Prinsen et al. 2019). The hypotheses should include the expected direction and magnitude of the correlations, and the constructs should be clearly described. Responsiveness can also be assessed by analysing weather EQ-5D-3L and EQ VAS can discriminate between patients who have improved and those that have not, based on changes in another outcome, such as changes in disease activity or functional ability (Mokkink, Prinsen et al. 2019). See hypotheses in document Study Protocol and Statistical Analysis Plan., One year. The two first EQ-5D-3L and EQ VAS measurements of patients with newly diagnosed disease (having the diagnosis for ≤12 months) during the first year for patients included during the period 2008-2024