O37 Utility of RA classification criteria in early inflammatory arthritis referral prioritisation

Abstract

Abstract Background Early arthritis clinics are increasingly utilised as a method of ensuring patients suspected of disease are assessed promptly to enable suitable treatment. Early recognition with treat to target has been demonstrated in systematic reviews to significantly improve mortality and morbidity outcomes. The United Kingdom’s National Institute for Health and Care Excellence (NICE) recommend potentially affected patients are referred from primary care within 3 days and seen in secondary care within 3 weeks. We hypothesised that utilising the ACR/EULAR 2010 rheumatoid arthritis classification criteria we could identify variables within the primary care referral which make an early arthritis more or less likely. Methods A retrospective study of all the patients seen in early inflammatory arthritis (EIA) Clinic from September 2017 to August 2018 in Aneurin Bevan University Health Board. EULAR scores of 145 patients were calculated based on the data provided in the primary care referral. These scores and their components were then compared to the eventual diagnosis. Results EULAR score of ≥ 5 had specificity of > 78% and sensitivity of < 30% in predicting EIA. EULAR score of 8 or more was 100% specific for EIA with positive likelihood ratio of infinity. Whereas EULAR score < 3 had a specificity of > 70% and sensitivity of < 45% for Non EIA with a positive likelihood ratio of 1.59. Considering individual EULAR components a high positive Rheumatoid Factor (RF) or Anti-citrullinated peptide antibody (ACPA) and involvement of greater than 10 joints had a positive likelihood ratio of ≥ 3.00 for EIA. A low positive RF or ACPA had a specificity of 66.67% and sensitivity of 27.59% for EIA with a positive likelihood ratio of 0.83. Surprisingly involvement of 4-10 small joints or 2-10 large joints or just 1 large joint had a specificity of ≥ 75% for EIA and a positive likelihood ratio of greater than 1.00. A positive ESR or CRP had a specificity of 36.84% and sensitivity of 67.92% with a positive likelihood ratio for EIA of 1.08. A negative ESR and CRP had a specificity of 67.92% and a sensitivity of 35.00% for Non EIA with a positive likelihood ratio of 1.09. The duration of symptoms of < 6 weeks had a specificity of 77.55% and sensitivity of 24.39% with positive likelihood ratio for Non EIA of 1.08, however duration of > 6 weeks had a positive likelihood ratio of 0.97 for EIA with a lower specificity of 22.45% . Conclusion The total EULAR score and individual components can be used to prioritize primary care referrals. A EULAR score of less than 3, duration of symptoms of < 6 weeks, a negative ESR and CRP, a low positive RF or ACPA makes EIA less likely. Disclosures S.M. Imaduddin None. P. O'Biern None.