EXTENDED REPORT Application of the 2010 ACR/EULAR classification criteria in patients with very early inflammatory arthritis: analysis of sensitivity, specificity and predictive values in the SAVE study cohort Iuliia Biliavska, 1,2 Tanja A Stamm, 2 Jose Martinez-Avila, 2 Thomas W J Huizinga, 3 Robert B M Landewé, 4 Günter Steiner, 2 Daniel Aletaha, 2 Josef S Smolen, 2 Klaus P Machold 2 Handling editor Tore K Kvien 1 Department of non- coronarogenic Heart Disease and Clinical Rheumatology, NSC Institute of Cardiology, Kiev, Ukraine 2 Department of Rheumatology, Medical University of Vienna, Vienna, Austria 3 Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands 4 Department of Clinical Immunology & Rheumatology, Academic Medical Center/ University of Amsterdam and Atrium Medical Center Heerlen, Amsterdam, The Netherlands Correspondence to Professor Klaus Peter Machold, Department of Rheumatology, Internal Mediciine III, Medical University of Vienna, Währinger Gürtel 18-20, Vienna A-1090, Austria; Klaus.machold@meduniwien. ac.at Accepted 7 August 2012 Published Online First 15 September 2012 ABSTRACT Objective Performance of the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) rheumatoid arthritis (RA) criteria was analysed in an internationally recruited early arthritis cohort (≤16 weeks symptom duration) enrolled in the ‘Stop-Arthritis-Very-Early ’ trial. This sample includes patients with a variety of diseases diagnosed during follow-up. Methods Two endpoints were defined: Investigators’ diagnosis and disease-modifying antirheumatic drug (DMARD) treatment start during the 12-month follow-up. The 2010 criteria were applied to score Patients’ baseline data. Sensitivity, specificity, predictive values and areas under the receiver operating curves of this scoring with respect to both endpoints were calculated and compared to the 1987 criteria. The optimum level of agreement between the endpoints and the 2010 classification score ways estimated by Cohen’s ϰ coefficients. Results 303 patients had 12-months follow-up. Positive predictive values of the 2010 criteria were 0.68 and 0.71 for RA-diagnosis and DMARD-start, respectively. Sensitivity for RA-diagnosis was 0.85, for DMARD-start 0.8, whereas the 1987 criteria’s sensitivities were 0.65 and 0.55. The areas under the receiver operating curves of the 2010 criteria for RA-diagnosis and DMARD-start were 0.83 and 0.78. Analysis of inter-rater-agreement using Cohen’s ϰ demonstrated the highest ϰ values (0.5 for RA-diagnosis and 0.43 for DMARD-start) for the score of 6. Conclusions In this international very early arthritis cohort predictive and discriminative abilities of the 2010 ACR/EULAR classification criteria were satisfactory and substantially superior to the ‘old’ 1987 classification criteria. This easier classification of RA in early stages will allow targeting truly early disease stages with appropriate therapy. INTRODUCTION Early diagnosis and adequate therapeutic interven- tion with disease-modifying antirheumatic drugs (DMARDs) has become a major goal in the man- agement of rheumatoid arthritis (RA), because it significantly improves clinical outcomes and reduces the level of joint damage and disability. However, similar to other chronic diseases, there is no «gold» standard for the diagnosis of RA. 1–4 The 1987 American College of Rheumatology (ACR) RA classification criteria, while very specific in patients with established RA, are limited in their sensitivity to identify early disease stages. 5 In 2010 the ACR and the European League Against Rheumatism (EULAR) released new classification criteria for RA. 67 These aim to identify and clas- sify, among patients with inflammatory arthritis, those with early RA and in particular those with the highest risk of persistent and/or erosive disease. These individuals most likely benefit from early start of therapy with DMARDs. To develop these criteria, data from nine early arthritis cohorts were analysed to identify the factors (and their relative weights) associated with a clinical decision to start methotrexate (MTX) within the first 12 months. 8 9 Recently, several studies have assessed the diagnostic accuracy of the 2010 ACR/ EULAR classification criteria in comparison to other diagnostic or classification criteria (ie, the 1987 criteria) in several cohorts of patients; 10–15 in addition, the 1987 and 2010 criteria have been compared to each other in one of the cited studies 14 and three other cohorts. 16–18 Overall, the 2010 classification criteria performed well as com- pared with the 1987 criteria especially regarding the diagnosis of early RA, but some patients were missed, especially when being seronegative and having arthritis of <10 joints. 14 Moreover, these cohort analyses included (with one exception) patients with longer disease duration and all were done in the framework of a single centre/region With increasing levels of public information on the importance of early diagnosis of RA and refer- ral recommendations, the most important chal- lenge today relates to patients with very early arthritis. The ‘Stop Arthritis Very Early ’ (SAVE) trial 19 included between 2004 ( first patient’s first visit: 1 March 2004) and 2007 (last patient’s last visit: 31 August 2007) exactly such a population, namely patients with any type of arthritis of ≤4 months of symptoms and thus reflected the whole clinical spectrum of individuals with very early joint disease, spanning from those experien- cing spontaneous remission to those truly develop- ing RA. Moreover, SAVE derived its large number Open Access Scan to access more free content Ann Rheum Dis 2013;72:1335–1341. doi:10.1136/annrheumdis-2012-201909 1335 Clinical and epidemiological research on January 25, 2022 by guest. Protected by copyright. http://ard.bmj.com/ Ann Rheum Dis: first published as 10.1136/annrheumdis-2012-201909 on 15 September 2012. Downloaded from