POS1451 DEVELOPING A TOOL TO MEASURE THE LEARNING CURVE: ENTHESITIS ULTRASOUND IN PSORIASIS ARTHRITIS
Authors: S. Brådland, P. Andel, A. Diamandopoulos, G. Haugeberg
Journal: Annals of the Rheumatic Diseases (2021)

Background: Enthesitis is defined as inflammation of the tendon inserting the bone encompassing the adjacent trabecular bone network, the fascia and surrounding soft tissues as the cartilage, the bursa and the fat pad. In enthesitis clinical examination alone is a method with significant limitations in terms of diagnostic accuracy and does not correlate strongly with imaging diagnostics (1,2). Ultrasound (US) is a widely used imaging technique in Rheumatology. But while learning curricula and standardization for joint US are available, other US techniques as vascular-, enthesis- or serosa-US gets usually less attention in rheumatologic US curricula. Though both OMERACT (4) and GRAPPA (3) have recently published qualitative and semi quantitative criteria in enthesitis US, few publications explicitly address the learning curves in these particular domain. Objectives: To describe the development of a tool to measure the learning curve for enthesitis US. Methods: 3237 US images of 561 enthesis were obtained by one experienced ultrasonographer (PMA) in B- and color Doppler (CD) mode in longstanding psoriasis arthritis patients of different disease activity. Due to duplicity and poorer image quality 2115 images were eliminated. The remaining fully anonymized 1122 images (561 enthesis) were afterward implemented in a random multiple choice algorithm presenting a B-mode and a CD image of the same enthesis at the same time without timely limitation. Rating follows qualitative GRAPPA criteria as well as semiquantitative OMERACT criteria (3, 4). The enthesitis scoring application was than written in.NET/ C#, TypeScript and ReactJS and is hosted in Azure Cloud platform. The scoring is stored in a database allowing extraction to SPSS for statistical analysis. Results: The interface of the functional program is shown in image 1 (Screenshot). In a next step the program will be presented to different raters of different ultrasound experience (&gt;10 years, 5-10 years, 1-5 years, &lt;1 years). The program will be presented a multitude of times in different order to every rater to adjust for inter-rater reliability. Correlation between raters will be given to depict a learning curve on enthesitis ultrasound assuming the rater with the highest experience as gold standard. Image 1. Screenshot of grafical user interface of the scoring program. Conclusion: In this presentation we outline the successful development of a tool to measure the learning curve in enthesitis. We hypothesize that knowledge about the learning curve and inter-rater reliability in enthesitis US obtained by our tool might contribute to future US curricula, structured reporting and deep learning algorithms. References: [1]Achilles enthesitis defined by ultrasound is not associated with clinical enthesitis in patients with psoriatic arthritis, Brigitte Michelsen et al. RMD Open 2017;3 [2]Ultrasonographic evaluation in psoriatic arthritis is of major importance in evaluating disease activity Brigitte Michelsen et al. Annals of the Rheumatic Diseases 12(2108-2113) [3]Development of a Preliminary Ultrasonographic Enthesitis Score in Psoriatic Arthritis -GRAPPA Ultrasound Working Group, Stephanie Tom et al. The Journal of Rheumatology; 4(384-390) [4]Reliability of a consensus-based ultrasound definition and scoring for enthesitis in spondyloarthritis and psoriatic arthritis: an OMERACT US initiative, Peter V Balint et al. Annals of the Rheumatic Diseases, 12(1730-1735) Disclosure of Interests: None declared