Abstract
Objective Multimorbidity, the co-existence of 2 or more conditions in an individual, is associated with morbidity and mortality in the general population. This study aims to describe the prevalence of multimorbidity in axial spondyloarthropathy (axSpA) and assess its association with disease outcome measures.
Methods This cross-sectional study was conducted within the Ankylosing Spondylitis Registry of Ireland (ASRI) cohort. Structured standardised assessment was performed. Multimorbidity was considered as the presence of at least 1 physician-diagnosed chronic condition (excluding extra-articular manifestations) in addition to axSpA. Validated outcome measures were collected: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Health Assessment Questionnaire (HAQ), AS Quality of Life (ASQoL), Bath AS Metrology Index (BASMI). Adjusted multiple regression was performed to investigate the association between multimorbidity and disease outcomes.
Results A total of 734 patients from 12 centres were included: 77% male, mean (SD) age 45 (12) years. Of the cohort, 55% (n=403) are multimorbid. Multimorbid patients are significantly (p<0.01) older than axSpA-only patients (50 (12) v 40 (11) years). Obesity is the most prevalent chronic condition, affecting 27%. Multimorbid patients have more severe disease than patients with axSpA only. After adjusting for confounders, multimorbidity was associated with higher BASDAI (ß=0.7, 95% CI 0.34 to 1.05), BASMI (ß=0.45, 95% CI 0.09 to 0.80), BASFI (ß=0. 5, 95% CI 0.23 to 0.78), HAQ (ß=0.07, 95% CI 0.00 to 0.13) and ASQoL (ß=0.87, 95% CI 0.28 to 1.46).
Conclusion Multimorbidity is prevalent in axSpA and is associated with more severe disease.
