SAT0538 THE LEVEL OF AGREEMENT BETWEEN CLINICAL EXAMINATION AND ULTRASONOGRAPHY IN EARLY ARTHRITIS
Authors: Flavio Costa, Luisa Brites, João Dinis de Freitas, Sara Serra, Mariana Santiago, João Rovisco, Margarida Coutinho, José Antonio P. Da Silva, Catia Duarte
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Over the past decades, Early Arthritis Clinics (EAC) have been created to identify early arthritis and institute appropriate treatment as soon as possible. In Rheumatoid Arthritis (RA) many studies show that ultrasonography (US) is superior to clinical exam for the detection of synovitis and has good correlation with clinical findings and markers of inflammation and can be used to improve the certainty of a diagnosis of RA.<sup>1</sup>. However, few studies address the agreement between the US with the clinical examination in patients with early arthritis. <h3>Objectives:</h3> To evaluate the agreement between clinical examination and US findings of metacarpophalangeal and proximal interphalangeal joints of patients with early arthritis <h3>Methods:</h3> Patients from the EAC of our department with suspect arthralgia were included. Patients were submitted to clinical evaluation by a rheumatologist to identify tender and swollen joints. They were then submitted to an US examination of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints, by an experienced sonographer oblivious of the previous examination. Each joint was scored for the presence of synovial hypertrophy (SH) and Power Doppler (PD) signal. Based on OMERACT guidance, we defined synovitis as: ≥ grade 1 grey scale synovitis (hypoechoic SH regardless of the presence of effusion) and ≤ grade 1 power-Doppler. The diagnostic value of clinical evaluation was assessed through sensitivity, specificity, Negative predictive value (NPV) and Positive predictive value (PPV), assuming the US synovitis as gold standard. Clinical arthritis was defined by joint swelling. Cohen's kappa coefficient was used to analyse concordance between joint swelling appreciated by clinical exam and HS, PD and the presence of US synovitis. Kappa values &lt; 0 were considered poor, 0-0.20 slight, 0.21-0.40 fair, 0.41-0.60 moderate, 0.61-0.80 good and 0.81-1.00 excellent.<sup>2</sup> Statistical significance was defined as p&lt;0.05. Statistical analysis was performed using IBM SPSS Statistics, version 21.0. <h3>Results:</h3> 77 consecutive patients were included (53.2% female) with a mean age of 53.8±19.1 years. We evaluated 770 MCP and 770 PIP joints. The sensitivity and specificity of clinical examination in relation to US synovitis was respectively 71% and 60% for MCP and 54.5% and 43.9% for PIP. The NPV and PPV for MCP were 87.8% and 33.3% respectively, and for PIP were 85.3% and 13.9%. The level of agreement between joint swelling and HS, PD and the presence of synovitis is show on Table 1. <h3>Conclusion:</h3> The clinical evaluation of MCP showed a better performance than clinical evaluation of PIP. The high NPV of clinical examination makes its suitable to be used to rule out MCP and PIP involvement in patients with early arthritis. The performance of the two assessment strategies on the same day may increase agreement and diagnostic certainty. <h3>References</h3> [1] - Colebatch AN, et al. EULAR recommendations for the use of imaging of the joints in the clinical management of rheumatoid arthritis. Annals of the Rheumatic Diseases2013;72:804-814. [2] - McHugh. Interrater reliability: the kappa statistic. Biochem Med (Zagreb). 2012;22(3):276-82. <h3>Disclosure of Interests:</h3> None declared