The National Prevalence of Clinically Diagnosed Psoriatic Arthritis in Sweden in 2017

Sofia Exarchou; Johan K Wallman; Daniela Di Giuseppe; Eva Klingberg; Valgerdur Sigurdardottir; Sara Wedrén; Ulf Lindström; Carl Turesson; Lennart T H Jacobsson; Johan Askling

doi:10.3899/jrheum.221139

The National Prevalence of Clinically Diagnosed Psoriatic Arthritis in Sweden in 2017

J Rheumatol. 2023 Jun;50(6):781-788. doi: 10.3899/jrheum.221139. Epub 2023 Mar 1.

Authors

Affiliations

¹ S. Exarchou, MD, PhD, Department of Clinical Sciences Malmö, Rheumatology, Lund University, Malmö; sofiaexar@hotmail.com.
² J.K. Wallman, MD, PhD, Department of Clinical Sciences Lund, Rheumatology, Lund University, and Department of Rheumatology, Skåne University Hospital, Lund.
³ D. Di Giuseppe, PhD, J. Askling, MD, PhD, Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet, Stockholm.
⁴ E. Klingberg, MD, PhD, Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, and Department of Rheumatology, Sahlgrenska University Hospital, Gothenburg.
⁵ V. Sigurdardottir, MD, Center for Clinical Research (CKF) Dalarna, Uppsala University, and Department of Rheumatology, Falun Hospital, Falun.
⁶ S. Wedrén, MD, PhD, Department of Medicine Solna, Clinical Epidemiology Division, Karolinska Institutet, and Department of Rheumatology, Karolinska University Hospital, Stockholm.
⁷ U. Lindström, MD, PhD, L.T.H. Jacobsson, MD, PhD, Department of Rheumatology and Inflammation Research, Sahlgrenska Academy, University of Gothenburg, Gothenburg.
⁸ C. Turesson, MD, PhD, Department of Clinical Sciences Malmö, Rheumatology, Lund University, and Department of Rheumatology, Skåne University Hospital, Malmö, Sweden.

PMID: 36858434
DOI: 10.3899/jrheum.221139

Abstract

Objective: Psoriatic arthritis (PsA) prevalence estimates vary across studies; studies based on national data are few. We aimed to estimate the prevalence of clinically diagnosed PsA in Sweden in 2017, overall and stratified by sex, age, education, and geography, and to quantify disease-modifying antirheumatic drug (DMARD) use among those in contact with specialized rheumatology care between 2015 and 2017.

Methods: Individuals who were 18 to 79 years of age, alive and residing in Sweden on December 31, 2017, and had a prior PsA diagnosis were identified from the National Patient Register (NPR) and/or the Swedish Rheumatology Quality Register (SRQ). PsA prevalence was estimated according to a base case (BC) definition (ie, ≥ 1 main PsA International Classification of Diseases code from rheumatology or internal medicine departments in the NPR or a PsA diagnosis in the SRQ), according to 4 sensitivity analysis definitions, and for those seen in specialized rheumatology care between 2015 and 2017. In the latter group, DMARD use during 2017 was also assessed. Data for stratifications were retrieved from national registers.

Results: The crude national prevalence of PsA for adults, aged 18 to 79 years, was estimated at 0.39%, according to the BC definition; 0.34% after accounting for diagnostic misclassification; and 0.32% to 0.50% across all sensitivity analyses. The prevalence was lower in males and in those with a higher level of education. The prevalence for those seen in specialized rheumatology care between 2015 and 2017 was estimated at 0.24%. During 2017, 32% of patients in this population received biologic or targeted synthetic DMARDs, and 41% received conventional synthetic DMARDs only.

Conclusion: The prevalence of clinically diagnosed PsA in adults, aged 18 to 79 years, in Sweden in 2017 was around 0.35%. Among PsA cases in recent contact with specialized rheumatology care, almost three-fourths received DMARD therapy in 2017.

Keywords: DMARD; Sweden; epidemiology; prevalence; psoriatic arthritis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Antirheumatic Agents* / therapeutic use
Arthritis, Psoriatic* / diagnosis
Arthritis, Psoriatic* / drug therapy
Arthritis, Psoriatic* / epidemiology
Humans
Male
Prevalence
Rheumatology*
Sweden / epidemiology

Substances

Antirheumatic Agents