AB1235 COST-SAVING FOR HEALTH SERVICES DETECTING THE MISDIAGNOSIS OF RHEUMATOID ARTHRITIS USING IMAGING IN THE PROCESS OF DIAGNOSIS: EVIDENCE FROM REAL-WORLD

Background: The diagnosis of rheumatoid arthritis (RA) using EULAR criteria through conventional assessments remains controversial, especially for those with seronegative results, many of patients without other diagnostic aids as imaging, could be wrong diagnosed followed by expensive treatments (1-3). Objectives: To evidence through real-world data how the use of imaging within a screening process of diagnosis of RA can saving future costs for unnecessary treatments in patients with misdiagnosis of RA. Methods: A retrospective real-world data (RWD) analysis was developed from medical records of patients with presumptive RA diagnosis reportedly seronegative for both rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (ACPA), and who met ACR/EULAR 2010 classification criteria, in the period between July 2016 and June of 2017; patients were assessed by imagenology (X-ray, ultrasound (US) or magnetic resonance imaging (MRI) according to the screening diagnosis protocol in a center of integral attention for rheumatoid arthritis (CIA-RA) in order to confirm diagnosis of RA, or classify patients in an alternative proper diagnosis. Direct costs of diagnosis was estimated in two scenarios: the conventional diagnosis and the screening process of diagnosis in the CIA-RA. To quantify the cost-savings for this process we also estimated the cost of treatment for the first year after diagnosis for patients with RA and patients with the most common diagnosis found after screening. Results: 440 patients were referred to our center with presumptive diagnosis of RA in the period, who were assessed for ACPA and RF obtaining a seronegative result for both. After screening process just 115 patients were classified as RA, 99 as SRA and 16 as Nonspecific RA; 12.2% were identified by X-Ray, 67.7% were identified by US and 20% by MRI. The most frequently misdiagnosis found was Osteoarthritis in the 72.5% of patients assessed by the screening process. In that way, the conventional diagnosis cost $54.4, while the CIA-RA screening diagnosis cost was $247.1 per patient, however there was found a potential cost-saving from using the CIA-RA screening process of diagnosis of $1,440,494 per year due to the pharmacological cost saving of 325 patients who requires treatment for OA and not for RA. Conclusion: According with our findings the use of imaging within a diagnostic screening process combining conventional criteria is a useful tool to discard false positive diagnosis of RA. Despite the fact that at first sight, the cost of screening process of diagnosis is more expensive than conventional diagnosis, after one year of treatment it can be assumed potential cost-savings using the proposed approach. References [1] Hu H, Luan L, Yang K, Li S-C. Burden of rheumatoid arthritis from a societal perspective: A prevalence-based study on cost of illness for patients with rheumatoid arthritis in China. Int J Rheum Dis [Internet]. 2017 Feb 17 [cited 2017 Mar 1]; Available from: http://www.ncbi.nlm.nih.gov/pubmed/28211251 [2] Cross M, Smith E, Hoy D, Carmona L, Wolfe F, Vos T, et al. The global burden of rheumatoid arthritis: estimates from the Global Burden of Disease 2010 study. Ann Rheum Dis. 2014;73(6). [3] Ostergaard M, Pedersen SJ, Dohn UM. Imaging in rheumatoid arthritis - status and recent advances for magnetic resonance imaging, ultrasonography, computed tomography and conventional radiography. Best Pract Res Clin Rheumatol [Internet]. 2008;22(6):1019–44. Available from: http://dx.doi.org/10.1016/j.berh.2008.09.014 Disclosure of Interests: Omaira Valencia: None declared, Pedro Santos-Moreno Grant/research support from: Dr Santos has received research grants from Janssen, Abbvie and UCB, Speakers bureau: Dr Santos has received speaker fees from Sanofi, Lilly, Bristol, Pfizer, Abbvie, Janssen and UCB, Edwin Castillo: None declared, Nelson Alvis : None declared