Figure 1 Association between gross domestic product per capita (GDP) and disease activity score in 28 joints (DAS28) in 18 European countries and the USA in the QUEST–RA study. The correlation of GDP with DAS28 is r = 20.85 (95% CI 20.63 to 20.94); indicated with colour. GDP is expressed as 1000J per capita. DAS28 ranges from 0 to 9.1 (low–high disease activity). The area of the disk is proportional to the total national health expenditure of each country in 2004. De, Denmark; Es, Estonia; Fi, Finland; Fr, France; Ge, Germany; Gr, Greece; Hu, Hungary; Ir, Ireland; It, Italy; Ko, Kosovo; La, Latvia; Li, Lithuania; Ne, The Netherlands; Po, Poland; Se, Serbia; Sp, Spain; Sw, Sweden. socioeconomic status with poor health and high mortality may be explained as much or ever better by psychosocial and behavioural variables as by ‘‘medical’’ variables, according to a ‘‘biopsychoso- cial model’’ to complement a biomedical model.23 24 27 28 In the present study, psychological distress appeared significantly greater in ‘‘low GDP’’ than in ‘‘high GDP’’ countries. Several limitations are seen in this study. First, cross-sectional QUEST–RA data cannot address definitively whether the biology of RA is more severe in less wealthy versus wealthy countries. GDP may serve as a surrogate marker for many variables, some related and others unrelated directly to medical care. Second, a limited number of patients were included per country. Nonetheless, results were quite similar among clinics within each country.10 Furthermore, it is not possible to obtain optimal clinical information on large numbers of patients, with accurate physical examination and physician-recorded diagnosis for diseases such as RA, using only surveys. RA is not diagnosed according to a single ‘‘gold standard’’ measure as seen for hypertension or diabetes, but according to a set of measures, requiring a knowledgeable clinician. Third, it is possible that only RA patients with poor clinical status visit clinics in countries with lower GDP, and patients with better status in rich countries seek medical care. While this possibility cannot be excluded, the study was designed to incorporate a cross section of patients seen in various countries. Clinical trials in patients with RA tend to be performed in countries with lower GDP at this time, as most patients in countries with higher GDP do not meet inclusion criteria,29 indicating the likelihood of an accurate representation of the present study. These results illustrate the potential value of collaborative databases, with identical database architecture, to provide an opportunity to study associations between disease characteristics, Ann Rheum Dis 2009;68:1666–1672. doi:10.1136/ard.2009.109983 Extended report therapies and outcomes at many sites in many countries with different economic levels. The QUEST–RA database may appear somewhat complex, although the collected data were regarded as consistent with appropriate good patient care. The only payments made to physicians were to cover the costs of materials and mailing. Similar efforts could be conducted at low cost for many diseases and add useful information regarding clinical status, prognosis and monitoring. The status of patients with RA has been found to be significantly better in recent years than in previous decades.30–32 However, almost all of the published data have been derived from western European and north American nations. The data presented in this report, indicating disparities with other countries, present an important challenge. While it is possible that other nations may ‘‘catch up’’ over the next decade to advances in the wealthier nations at this time, disparities may continue to exist. Public health efforts would appear potentially to be as important as the introduction of new therapies to treat RA.33 Further research is needed to understand better the structure (demographic, macroeconomic), process (clinical and treatment variables) and outcomes (mortality, functional and work status), which may contribute to differences in quality of care for patients with RA in different countries. Recognition of major differences in outcomes can lead to more informed efforts to improve the structure and process of care. The ultimate goal of these efforts is to improve outcomes for patients with RA in all countries. Author affiliations: 1 Jyv¨askyl¨a Central Hospital, Jyv¨askyl¨a; Medcare Oy, A¨¨anekoski, Finland; 2 Unit of Family Practice, Jyv¨askyl¨a Central Hospital, Jyv¨askyl¨a, and ORTON, Rehabilitation Unit, Helsinki, Finland; 3 NYU Hospital for Joint Diseases, New York, NY, USA; 4 Hospital San Juan Bautista, Catamarca, Argentina; 5 Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil; 6 Riverside Professional Center, Sydney, NS, Canada; 7 Copenhagen Univ Hospital at Hvidovre, Hvidovre, Denmark; 8 East-Tallinn Central Hospital, Tallinn, Estonia; 9 North Karelia Central Hospital, Joensuu, Finland; 10 Dijon University Hospital, University of Burgundy and INSERM U887, Dijon, France; 11 University of Ioannina, Ioannina, Greece; 12 Schlosspark-Klinik, Berlin, Germany; 13 Polyclinic of the Hospitaller Brothers of St. John of God in Budapest, Budapest, Hungary; 14 St. Vincent University Hospital, Dublin, Ireland; 15 Our Lady’s Hospice, Dublin, Ireland; 16 Santa Chiara Hospital, Pisa, Italy; 17 Rheumatology Department, Pristine, Kosovo; 18 Pauls Stradina Clinical University Hospital, Riga, Latvia; 19 Institute of Experimental and Clinical Medicine at Vilnius University, Vilnius, Lithuania; 20 Sint Franciscus Gasthuis Hospital, Rotterdam, Netherlands; 21 Medical University in Bialystok, Bialystok, Poland; 22 Early Arthritis Department, Institute of Rheumatology of Russian Academy of Medical Sciences, Moscow, Russia; 23 Rheumatology Institut, Niska Banja, Serbia; 24 Hospital de Gran Canaria Dr. Negrin, Las Palmas, Spain; 25 Uppsala University Hospital, Uppsala, Sweden; 26 Gazi University Medical Faculty, Ankara, Turkey; 27 Dubai Bone and Joint Center, Dubai, United Arab Emirates; 28 American Hospital Dubai, Dubai, United Arab Emirates; 29 University Medical Faculty, Charing Cross Hospital, London, UK Acknowledgements: The authors are grateful to all investigators in the QUEST–RA project (whose names are listed in a supplemental file available online only). Funding: TS has received grants from Central Finland Health Care District and Heinola Rheumatism Foundation Hospital (EVO grants). Funding sources did not participate in the study design and the collection, management, analysis and interpretation of data, and preparation, review, or approval of the manuscript and the decision to submit it for publication. Competing interests: None. Ethics approval: The study was carried out in compliance with the Helsinki Declaration. Ethics Committees or Internal Review Boards of participating institutes approved the study. Patient consent: Obtained. Contributors: Study design: TS, TP, HK. Acquisition of data: The entire QUEST–RA study group. Analyses and interpretation of data: TS, HK, TP. Preparation of the manuscript and approval of the final version: The entire QUEST–RA study group. All researchers had access to all the data. TS takes responsibility for the integrity of the data and the accuracy of the data analysis. Provenance and peer review: Not commissioned; externally peer reviewed. 1671