Associations of patient-reported outcome measures with impaired mobility and elevated C reactive protein in axial spondyloarthritis: a cross-sectional study
Year: 2026
Type: article
Study design: Observational Study
Abstract: Objectives To examine associations between patient-reported outcome measures (PROMs) for disease activity, physical function and well-being and clinical measurements for mobility as well as C reactive protein (CRP) in axial spondyloarthritis (axSpA). A secondary aim was to explore cut-off values that may serve as indicators to prompt further mobility assessment or consideration of treatment adjustment.Methods This cross-sectional study used data from 22 105 visits among 5095 individuals with axSpA, registered in the Swedish Rheumatology Quality Register. Variables for PROMs were Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Global Score. Variables for clinical measurements were Bath Ankylosing Spondylitis Metrology Index (BASMI) and CRP. Associations were tested with Pearson’s correlations. Receiver operating characteristic (ROC) curve analysis assessed discrimination of impaired spinal mobility in BASMI or elevated CRP for variables with r ≥0.5.Results Associations with r ≥0.5 were found only between BASFI and BASMI (r=0.51), resulting in an area under the curve of 0.74 (95% CI 0.71 to 0.76) in the ROC analyses. The strongest associations were found between BASFI subquestions 5 (getting up off the floor without help from lying on your back) and 8 (looking over your shoulder without turning your body) and BASMI sum (r=0.5 and r=0.63, respectively).Conclusions BASFI and its subquestions 5 and 8 may be helpful in identifying individuals with axSpA who require further mobility measuring. Neither PROMs associate with CRP to any higher degree (r <0.5), which reinforces that PROMs cannot replace objective inflammatory markers.
Source: RMD Open
Institutions: Uppsala University, Umeå University, Region Gävleborg
Language: English
Subfield: Rheumatology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,391
Funder: Uppsala Universitet
OpenAlex ID: W7221806388