OBJECTIVES: To compare the disease burden for patients with non-radiographic axial spondyloarthritis (nr-axSpA) to those with ankylosing spondylitis (AS) in the real world.

METHODS: This retrospective analysis used data from the Adelphi Spondyloarthritis Disease Specific Programme, which collected information from rheumatologists and their consulting nr-axSpA and AS patients across Europe, Asia-Pacific, US, Latin America, and Middle East between 2015 and 2016. The difference in demographics, clinical profile, patient-reported pain, disease activity (Bath ankylosing spondylitis disease activity index [BASDAI]), quality of life (EuroQol five dimensions [EQ-5D] and short-form [SF]-36), and work and activity impairment (WPAI) for patients with nr-axSpA vs AS was assessed using bivariate descriptive analysis and propensity score matching to match patients for confounding factors including demographics and clinical characteristics.

RESULTS: This analysis included data from 795 rheumatologists and 5,660 patients (nr-axSpA: 2,777, AS: 2,883). Nr-axSpA patients were younger (mean age, nr-axSpA: 41.1 years vs AS: 43.8 years, p<0.0001) and more frequently female (nr-axSpA: 44.1% vs AS: 25.8%, p<0.0001) compared with AS patients. Nr-axSpA patients had fewer symptoms at diagnosis and shorter time from diagnosis to first advanced treatment compared with AS patients (p<0.0001). Higher proportion of AS patients had current severe disease as assessed by rheumatologists (p=0.0178) and elevated C-reactive protein level at diagnosis (p<0.0001) vs nr-axSpA, whereas higher proportion of nr-axSpA patients had active sacroiliitis identified by magnetic resonance imaging (p<0.0001). In bivariate analysis as well as after adjusting for confounding factors, no significant differences in pain, EQ-5D, WPAI, and BASDAI were observed (all p>0.05). AS patients had lower SF-36 physical functioning scores (nr-axSpA: 70.5, AS: 66.7, p=0.046) than nr-axSpA patients, indicating more disability.

CONCLUSIONS: Results from this large multinational real world analysis confirm that patients with nr-axSpA and AS share a comparable degree of disease burden, and hence necessitate similar management and treatment strategies to improve patient outcomes.