SAT0447 Preliminary Definition of Cutoffs for High Disease Activity Based on Original and Simplified Jadas in Juvenile Idiopathic Arthritis

Background In the last decade, there have been major advances in the management of juvenile idiopathic arthritis (JIA), which include the shift towards early aggressive interventions and the development of new therapeutic agents and combination treatment strategies. A reliable documentation of the advances in therapeutic effectiveness creates the need for validated and clinically useful criteria that describe precisely the clinical states of the patient. Objectives To determine cut-off values for high disease activity (HDA) based on the original Juvenile Arthritis Disease Activity Score (JADAS) (1) and a simplified 3-item version of the JADAS (clinical JADAS- cJADAS), which does not include the acute phase reactant (2). Methods For the selection of cut-offs, data from a clinical database including 618 children with JIA followed at study center were used. ‘Optimal’ cut-offs were determined against external criteria by calculating the 25th percentile of cumulative score distribution and through receiver operating characteristic curve analysis. Patients were identified as being in HDA when the physician decided a major therapeutic intervention, defined as follows: 1) start of methotrexate therapy; 2) intraarticular corticosteroid injection (IAC); 3) start of biologic treatment; 4) start of systemic corticosteroid therapy. For each patient, 1 visit with HDA and 1 visit with no-HDA (i.e. visit in which none of the major therapeutic interventions listed above was made) were retained. The choice of cut-offs was made on clinical and statistical grounds. Results A total of 364 visits for oligoarticular-course patients (134 with HDA) and 412 visits for polyarticular-course patients (147 with HDA) were retained. The table shows the cutoffs (sensitivity/specificity) defined according to the different statistical methods and the AUC of the ROC curve. Proposed HDA cutoffs in oligoarticular-course JIA are 7.9 for JADAS10 and JADAS71, 7.2 for JADAS27, 7 for cJADAS10 and cJADAS71, and 6.5 for cJADAS 27. Proposed HDA cutoffs in polyarticular-course JIA are 12 for JADAS10 and JADAS71, 11 for JADAS27, cJADAS10 and cJADAS71, and 10 for cJADAS27. Conclusions We developed the HDA cutoffs for the JADAS and the cJADAS. The cutoffs need a thorough validation before being introduced in daily practice and clinical trials. References Consolaro A et al. Arthritis Rheum. 2009 May 15;61(5):658-66 McErlane F et al. Ann Rheum Dis. 2012 Epub ahead of print Disclosure of Interest None Declar