National Socioeconomic Status Influences Disease Severity at Treatment Start and Duration of Treatment in Patients with Psoriatic Arthritis and Axial Spondyloarthritis

A study initiated by the European Spondyloarthritis Research Collaboration Network (EuroSpA) examined whether where patients with psoriatic arthritis (PsA) or axial spondyloarthritis (axSpA) live is associated with the severity of their disease, when they begin advanced treatment, and how long they continue that treatment. Findingsopens in new tab/window in the Annals of the Rheumatic Diseasesopens in new tab/window (ARD), The EULAR Journal, published by Elsevier, found evidence that patients from wealthier European countries tend to start treatment with biologics earlier but also stop or switch treatment earlier. They also experience lower disease activity at treatment start than patients in middle- and low-income countries.

“We observed that patients’ disease activity and treatment outcomes varied across countries and wanted to understand whether differences in socioeconomic conditions between countries could explain some of these variations,” explains lead investigator Brigitte Michelsen, MD, PhD, Copenhagen Center for Arthritis Research (COPECARE), Rigshospitalet, Glostrup, Denmark; Sørlandet Hospital, Kristiansand, Norway; and Diakonhjemmet Hospital, Oslo, Norway.

Importantly, this research moves beyond individual patient factors and examines country-level socioeconomic influences on treatment outcomes across a large, real-world European cohort of patients. The study included 38,911 patients (17,296 with PsA and 21,615 with axSpA) in 13 European countries who began treatment with biologic or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) between 2015 and 2021. It assessed treatment retention at 6, 12, and 24 months after patients started treatment. Countries were categorized as low-, medium-, and high-income, according to national socioeconomic indicators.

Key Findings:

• Men and women with PsA or axSpA from countries with higher vs. lower gross domestic product per capita, current health expenditure per capita, gross national income per capita, out-of-pocket expenditure per capita, and human development index were more likely to have discontinued b/tsDMARDs at 6, 12, and 24 months.

• Country-level disease activity at b/tsDMARD initiation tended to be higher in lower- vs. higher-income countries. This was especially seen in PsA patients.

• Patients from wealthier countries showed shorter disease duration at initiation of b/tsDMARDs and higher proportions were women and current smokers.

This research highlights that national healthcare context and identifying system level inequalities matter. The cross-country differences identified should be recognized when interpreting treatment retention and outcomes. Further, the findings emphasize the importance of ensuring timely and equitable access to effective treatment for patients with PsA and axSpA, while also using advanced therapies appropriately and equitably.

The study highlights that countries with lower resources may need to focus on earlier identification of insufficient disease control and improved access to effective therapies, while high-income countries may need to ensure that frequent switching is clinically justified and aligned with patient benefit.

“This research is particularly important at this time because, although advanced treatment options have improved treatment practices, health system resources continue to differ between countries. For clinicians and policymakers, our findings highlight the importance of ensuring timely and equitable access to effective treatment for patients with PsA and axSpA, while also using these advanced therapies appropriately and equitably. This is of utmost relevance now, as health systems are increasingly focused on equitable access, cost-effective use of expensive therapies, and reducing unwarranted variation in care across countries,” concludes Dr. Michelsen.

“This is another important piece of evidence of how healthcare systems influence the approach to managing patients with various rheumatic diseases,” adds ARD Editor-in-Chief Josef Smolen, MD, from the Medical University of Vienna. “At ARD one of our primary roles is to improve equity in patient care across the globe, and the study by Michelsen and co-investigators constitutes an important example to further our understanding of inequities and improve care of patients with musculoskeletal and rheumatic diseases in the world.”

Notes for editors

The article is “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,” by Brigitte Michelsen, Christos Polysopoulos, Michael J. Nissen, Adrian Ciurea, Burkhard Möller, Lykke Midtbøll Ørnbjerg, Catalin Codreanu, Corina Mogosan, Gary J. Macfarlane, Gareth T. Jones, Bente Glintborg, Anne Gitte Loft, Bjorn Gudbjornsson, Gerdur Gröndal, Isabel Castrejón, Fernando Sánchez-Alonso, Ziga Rotar, Katja Perdan Pirkmajer, Karin Laas, Sigrid Vorobjov, Miguel Bernardes, Luís Cunha Miranda, Pia Isomäki, Johanna Huhtakangas, Johan K. Wallman, Jakub Závada, Karel Pavelka, Tore K. Kvien, Sella Aarrestad Provan, Pasoon Hellamand, Florenzo Iannone, Roberto Caporali, Jette Heberg, Simon Horskjær Rasmussen, Stig Winther Nielsen, Mikkel Østergaard, and Merete Lund Hetland (https://doi.org/10.1016/j.ard.2026.06.021opens in new tab/window). It appears online in the Annals of the Rheumatic Diseases, published by Elsevier.

The article is openly available at https://ard.eular.org/article/S0003-4967(26)00369-9/fulltextopens in new tab/window.

Full text of this article is also available to credentialed journalists upon request; contact Eileen Leahy at +1 732 406 1313 or [email protected]opens in new tab/window. Journalists wishing to interview the authors should contact Brigitte Michelsen, MD, PhD, at [email protected]opens in new tab/window; [email protected]opens in new tab/window, or [email protected]opens in new tab/window.

This EuroSpA study was financially supported by Novartis. No financial sponsors had any influence on the data collection, statistical analyses, manuscript preparation, or decision to submit.

About Annals of the Rheumatic Diseases (ARD)

Annals of the Rheumatic Diseasesopens in new tab/window (ARD), an official journal of EULARopens in new tab/window, is an international peer reviewed journal committed to promoting the highest standards of scientific exchange and education. It is the leading rheumatology journal publishing a combination of high-quality scientific papers, including original research, reviews, recommendations, viewpoints, and more. Clinical, basic, and translational science across the inflammatory and non-inflammatory musculoskeletal conditions are part and parcel of this spectrum.

About EULAR

EULARopens in new tab/window is the European umbrella organization representing scientific societies, health professional associations, and organizations for people with rheumatic and musculoskeletal diseases (RMDs). EULAR aims to reduce the impact of RMDs on individuals and society, as well as improve RMD treatments, prevention, and rehabilitation. To this end, EULAR fosters excellence in rheumatology education and research, promotes the translation of research advances into daily care, and advocates for the recognition of the needs of those living with RMDs by EU institutions.

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