Extended report c A supplemental file of QUEST- RA collaborators is published online only at http://ard.bmj. com/content/vol68/issue11 For numbered affiliations see end of article Correspondence to: Dr T Sokka, Arkisto/Tutkijat, Jyv¨askyl¨a Central Hospital, 40620 Jyv¨askyl¨a, Finland; tuulikki.sokka@ksshp.fi Accepted 19 May 2009 Published Online First 31 July 2009 This paper is freely available online under the BMJ Journals unlocked scheme, see http:// ard.bmj.com/info/unlocked.dtl 1666 Disparities in rheumatoid arthritis disease activity according to gross domestic product in 25 countries in the QUEST–RA database T Sokka,1 H Kautiainen,2 T Pincus,3 S Toloza,4 G da Rocha Castelar Pinheiro,5 J Lazovskis,6 M L Hetland,7 T Peets,8 K Immonen,9 J F Maillefert,10 A A Drosos,11 R Alten,12 C Pohl,12 B Rojkovich,13 B Bresnihan,14 P Minnock,15 M Cazzato,16 S Bombardieri,16 S Rexhepi,17 M Rexhepi,17 D Andersone,18 S Stropuviene,19 M Huisman,20 S Sierakowski,21 D Karateev,22 V Skakic,23 A Naranjo,24 E Baecklund,25 D Henrohn,25 F Gogus,26 H Badsha,27 A Mofti,28 P Taylor,29 C McClinton,29 Y Yazici3 ABSTRACT Objective: To analyse associations between the clinical status of patients with rheumatoid arthritis (RA) and the gross domestic product (GDP) of their resident country. Methods: The Quantitative Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST–RA) cohort includes clinical and questionnaire data from 6004 patients who were seen in usual care at 70 rheumatology clinics in 25 countries as of April 2008, including 18 European countries. Demographic variables, clinical characteristics, RA disease activity measures, including the disease activity score in 28 joints (DAS28), and treatment-related variables were analysed according to GDP per capita, including 14 ‘‘high GDP’’ countries with GDP per capita greater than US$24 000 and 11 ‘‘low GDP’’ countries with GDP per capita less than US$11 000. Results: Disease activity DAS28 ranged between 3.1 and 6.0 among the 25 countries and was significantly associated with GDP (r = 20.78, 95% CI 20.56 to 20.90, r2 = 61%). Disease activity levels differed substantially between ‘‘high GDP’’ and ‘‘low GDP’’ countries at much greater levels than according to whether patients were currently taking or not taking methotrexate, prednisone and/or biological agents. Conclusions: The clinical status of patients with RA was correlated significantly with GDP among 25 mostly European countries according to all disease measures, associated only modestly with the current use of antirheumatic medications. The burden of arthritis appears substantially greater in ‘‘low GDP’’ than in ‘‘high GDP’’ countries. These findings may alert healthcare professionals and designers of health policy towards improving the clinical status of patients with RA in all countries. Health disparities, including high mortality rates, are associated with low socioeconomic status in many specific diseases in many countries.1–6 Furthermore, differences in gross domestic product (GDP) in different countries are associated signifi- cantly with differences in mortality rates among countries.7–9 Most reports of these observations are based on surveys and national databases, with relatively limited information from clinical settings based on physical examination, laboratory tests, medications and patient self-report information concerning functional status, pain, psychosocial distress, etc, to understand further the basis for these disparities. Furthermore, little is known concerning associations of GDP and clinical out- comes of chronic disabling musculoskeletal condi- tions such as rheumatoid arthritis (RA). A multinational database Quantitative Standard Monitoring of Patients with Rheumatoid Arthritis (QUEST–RA)10 11 was established to assess 100 unselected consecutive patients with RA per clinic and included 25 countries by April 2008. Considerable variation was observed in clinical status in different countries according to most clinical measures, whether derived from the phy- sician, patient or laboratory, as well as the composite RA disease activity score in 28 joints (DAS28) index.12 In this report, we compare demographic characteristics, RA disease activity measures and treatment-related variables between ‘‘high GDP’’ and ‘‘low GDP’’ countries, and analyse associations between DAS28 and GDP. PATIENTS AND METHODS Establishment of database QUEST–RA was established in 2005 with the objectives of promoting quantitative assessment in usual rheumatology care, and to develop a baseline cross-sectional database of consecutive RA patients seen outside of clinical trials in regular care in many countries. Three or more rheumatologists were asked to enroll 100 consecutive unselected patients in each country.10 As of April 2008, the programme enrolled 6004 patients from 71 sites in 25 countries, including Argentina, Brazil, Canada, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Kosovo, Latvia, Lithuania, The Netherlands, Poland, Russia, Serbia, Spain, Sweden, Turkey, United Arab Emirates, the UK and the USA.11 The study was carried out in compliance with the Helsinki Declaration. Ethics Committees or Internal Review Boards of participating institutes approved the study, and a written informed consent was obtained from the patients. Physician assessment measures All patients were assessed according to a standard protocol to evaluate RA.13 The physician review Ann Rheum Dis 2009;68:1666–1672. doi:10.1136/ard.2009.109983