Psychometric properties and cross-language equivalence of the revised Bristol Rheumatoid Arthritis Fatigue and the Rheumatoid Arthritis Impact of Disease scales in rheumatoid arthritis.

ABSTRACT:

Objective

To assess psychometric properties and cross-language measurement equivalence of six versions of the Bristol Rheumatoid Arthritis Fatigue Scale (BRAF-MDQ) and the Rheumatoid Arthritis Impact of Disease Score (RAID in rheumatoid arthritis (RA).

Methods

Both questionnaires were completed by French (n = 206), German (n = 206), Dutch (n = 317), Spanish (n = 157), Swedish (n = 170) and UK (n = 210) RA patients. The presence of cross-language differential item functioning (DIF) was examined using the generalized partial credit model. The impact of DIF on the item and total scores was examined by comparing DIF unadjusted and DIF adjusted expected item and scale scores. IRT-based methods were used to assess psychometric properties of the instruments.

Results

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SUBMITTER: Oude Voshaar MAH 

PROVIDER: S-EPMC6698264 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature