DATA from 13 European countries have revealed that patients with psoriatic arthritis and axial spondyloarthritis in wealthier nations are more likely to discontinue biologic therapy than those in lower-income countries, despite generally better access to treatment.
Cross-country differences in biologic drug retention have previously been reported in rheumatoid arthritis, with lower retention observed in higher gross domestic product countries. In spondyloarthritis, cross-sectional studies have shown higher disease activity among patients from lower-income countries, yet the relationship between national socioeconomic status and both treatment retention and disease activity in psoriatic arthritis and axial spondyloarthritis has remained less well characterised.
Researchers analysed longitudinal data from 38,911 patients with spondyloarthritis (17,296 with psoriatic arthritis; 21,615 with axial spondyloarthritis) who initiated biologic or targeted synthetic disease-modifying antirheumatic drugs between 2015 and 2021 across 13 European countries, collected by the European Spondyloarthritis Research Collaboration Network. Countries were categorised by low, medium, or high socioeconomic indicators, including gross domestic product, the Human Development Index, gross national income, and health expenditure. Kaplan-Meier analysis, mixed-effects Cox regression, and mixed models compared drug retention and disease activity across countries, stratified by disease, treatment line, and sex.
Drug retention was significantly lower in both men and women with psoriatic arthritis or axial spondyloarthritis from countries with high versus medium or low gross domestic product per capita, after six, 12, and 24 months of treatment with first or subsequent biologic or targeted synthetic drugs (log-rank p<0.001). Across all socioeconomic indicators, higher national wealth was associated with earlier discontinuation of the first such drug, with the strongest associations seen for gross domestic product and the Human Development Index, and most prominently in women with axial spondyloarthritis. At the country level, most disease activity measures at treatment initiation were significantly worse with lower gross domestic product, particularly in psoriatic arthritis. Patients from wealthier countries tended to have shorter disease duration at treatment initiation, and higher proportions were women and current smokers.
These findings have shown that treatment retention for psoriatic arthritis and axial spondyloarthritis varies according to a country’s socioeconomic status. As this was an observational registry study, causality cannot be established, though differences in healthcare access, treatment thresholds, and national prescribing policies may contribute to the patterns observed. The authors have suggested that clinicians and policymakers should be aware of later treatment discontinuation and higher country-level disease activity at treatment initiation in lower-income countries, alongside more intensive treatment practices in higher-income countries.
Reference
Michelsen B et al. Influence of national socioeconomic status on treatment retention and disease activity in psoriatic arthritis and axial spondyloarthritis: evidence over 2 years in 13 European countries. Annals of the Rheumatic Diseases. 2026;DOI:10.1016/j.ard.2026.06.021.
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