ORIGINAL ARTICLE Welfare costs in patients with rheumatoid arthritis and their partners compared with matched controls: a register-based study Katrine Løppenthin 1 & Bente Appel Esbensen 1,2 & Mikkel Østergaard 1,2 & Rikke Ibsen 3 & Jakob Kjellberg 4 & Poul Jennum 2,5 Received: 22 July 2016 /Revised: 3 October 2016 /Accepted: 4 October 2016 /Published online: 25 October 2016 # International League of Associations for Rheumatology (ILAR) 2016 Abstract Rheumatoid arthritis (RA) is a chronic autoimmune disease with significant morbidity, mortality, and costs for the individual patient and for society. The purpose of this study was to examine welfare costs in patients with RA including their partners before and after initial diagnosis. Data were collected from population-based registers in the period from 1998 to 2009. A total of 25,547 Danish patients with a diag- nosis of RA and 15,660 of their partners were identified and compared with 101,755 randomly selected age- and gender- matched controls and 62,681 control partners. The direct and indirect costs were calculated for patients and their partners and compared to matched controls. These included inpatient and outpatient treatment, medication, income from employ- ment and social transfer payments. Patients with RA had sta- tistically significantly more inpatient and outpatient costs than control subjects, i.e., treatment (€346 vs. €211), hospitaliza- tion (€1261 vs. €778), and medication use (€654 vs. €393). The costs associated with the patients were present 11 years before diagnosis of RA (€1592) compared with control sub- jects (€1172). Furthermore, income from employment was lower for patients ( €14,023) than for control subjects (€17,196). Being a partner to a patient with RA was associated with high total welfare costs. This register-based study shows that RA has significant welfare costs for patients, their part- ners, and society. The differences in total health costs exist up to 11 years before the diagnosis of RA is established. Keywords Epidemiology < methodology . Health economics < methodology . Rheumatoid arthritis (RA) < rheumatic diseases . Total costs and rheumatoid arthritis Introduction Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation, primarily of the small joints of the hands and feet. RA affects approximately 0.3–1 % of the population worldwide [1, 2] with a peak onset of the disease between 40 and 70 years of age [3]. RA is associated with an increased incidence of comorbidities [4, 5], and consequently, a high risk of premature death [6]. Despite the fact that phar- macological treatment has improved, RA still has a significant negative impact on patients’ social life [7], lifestyle [8], and quality of life [9, 10]. In addition, and as a possible result of * Poul Jennum poul.joergen.jennum@regionh.dk Katrine Løppenthin Katrine.bjerre.loeppenthin@regionh.dk Bente Appel Esbensen bente.appel.esbensen@regionh.dk Mikkel Østergaard mo@dadlnet.dk Rikke Ibsen rikke@i2minds.dk Jakob Kjellberg jakj@kora.dk 1 Copenhagen Center for Arthritis Research, Center for Rheumatology and Spine Diseases, Centre of Head and Orthopaedics, Rigshospitalet, Copenhagen, Denmark 2 Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark 3 i2minds, Klosterport 4E, 4, Aarhus, Denmark 4 Danish National Institute for Local and Regional Government Research, Copenhagen, Denmark 5 Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Faculty of Health Sciences, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark Clin Rheumatol (2017) 36:517–525 DOI 10.1007/s10067-016-3446-z