Validation and reliability of translation of the ASAS Health Index in a Colombian Spanish-speaking population with spondyloarthritis

Abstract

To validate a Spanish language translation of the ASAS Heath-Index (ASAS-HI) testing, its reliability, construct validity, and responsiveness in Colombian patients with spondyloarthritis. Translation was done following a forward-backward procedure. Patients fulfilling the Assessment of Spondyloarthritis international Society (ASAS) criteria for either axial or peripheral spondyloarthritis (SpA) participated. Test-retest reliability was assessed by intra-class correlation coefficient (ICC) in patients without treatment changes. In patients who required a therapeutic intervention, responsiveness was assessed using the standardized response mean (SRM). Construct validity was evaluated by Spearman correlation. Internal consistency (Cronbach's α) and discriminative ability of the ASAS-HI were assessed. Fifty patients were included: 54% male, mean (SD) age 44.8 (13.1), symptom duration 15.8 (9.7) years, Bath Ankylosing Spondylitis Disease Index (BASDAI) 4.6 (2.2), Bath Ankylosing Spondylitis Functioning Index (BASFI) 4.7 (2.5), Ankylosing Spondylitis Disease Activity Score with C-Reactive Protein (ASDAS-CRP) 2.2 (1.0). Axial SpA was established in 44 patients (ankylosing spondylitis (AS) = 30, non-radiographic axial SpA (nr-axSpA) = 14) and peripheral SpA in 6 patients. The score of the ASAS-HI was 8.2 (5.1). The test-retest reliability was good with an ICC of 0.84. SRM was 2.58 (1.75-3.37) in 10 patients with any intervention and 2.94 (2.13-4.24) for 7 patients starting TNF blockers. Construct validity showed a good correlation between ASAS-HI and pain, BASDAI, BASFI, and Ankylosing Spondylitis Disease Activity Score (ASDAS) (r ≥ 0.60). A high internal consistency was found with a Cronbach's α of 0.91. ASAS-HI discriminated well between patients with different stages of disease activity (BASDAI and ASDAS). Those with higher disease activity had higher ASAS-HI scores. The Spanish language translation of the ASAS-HI has proven to be psychometrically valid for Colombian patients with SpA. This version is available to evaluate the state of health and functioning in these patients and can be used in clinical practice.

Keywords: Functioning; Health; Spondyloarthritis.