Global patterns and determinants of diagnostic delay in spondyloarthritis: insights from the ASAS-PerSpA international study.

Abstract

Diagnostic delay (DD) is well-documented in SpA, particularly in axial disease. This ancillary analysis from the ASAS-PerSpA study estimated DD across SpA entities, considering the presenting disease manifestation, and evaluated factors associated with DD. This study included 4339 patients with any SpA entity (axial (axSpA), peripheral (pSpA), PsA, inflammatory bowel disease-associated SpA (IBD-SpA), ReA and juvenile SpA). DD was assessed using two definitions: (1) the first included extra-musculoskeletal manifestation (EMM) if any, as possible initial symptom, and (2) the second considered strictly the first musculoskeletal manifestation (MM) as the disease onset. DD was statistically compared across disease entities, and associated factors were evaluated using multivariable linear regression models for axSpA, PsA, pSpA and IBD-SpA. The analysis included 2622 axSpA, 1016 PsA, 424 pSpA, 110 IBD-SpA, and 167 other SpA patients. The average DD was shorter using definition 2 (4.5 ± 7.0 vs 6.6 ± 8.6 years). Based on definition 2, DD was longer for axSpA and IBD-SpA (5.6 ± 7.3 and 5.2 ± 7.7 years, respectively), where the first MM was axial, compared with PsA (2.5 ± 6.1 years), pSpA (3.1 ± 5.9 years) and others, where it was peripheral (P < 0.001). Axial first manifestation, younger age at first symptom and older age at study inclusion were associated with longer DD in the four SpA entities. DD was longer in axSpA and IBD-SpA compared with PsA, pSpA and other forms of SpA and associated with the phenotype of the presenting symptom. SpA entities and presenting symptoms should be considered when reporting DD in SpA.