POS0258 REAL-TIME VERSUS STATIC SCORING IN MUSCULOSKELETAL ULTRASONOGRAPHY IN PATIENTS WITH INFLAMMATORY HAND OSTEOARTHRITIS
Authors: L. Van de Stadt, F. Kroon, M. Reijnierse, D. Van der Heijde, F. Rosendaal, N. Riyazi, R. De Slegte, J. Van Zeben, C. Allaart, M. Kloppenburg, M. Kortekaas
Journal: Annals of the Rheumatic Diseases (2021)

Background: Ultrasound (US) is used in rheumatic musculoskeletal diseases (RMDs) such as hand osteoarthritis (OA) as outcome measure. Traditionally scoring is performed real-time, but central reading of static US images could avoid issues of inter-rater reliability. However, agreement between real-time and static assessment has not been studied Objectives: To study the agreement between real-time and static scoring of US in inflammatory hand OA. Methods: Ultrasound was performed of 30 joints obtained in 75 patients with hand osteoarthritis, treated with prednisolone or placebo in a randomized double-blind trial. Hand joints were assessed for synovial thickening, effusion, Doppler signal and osteophytes by ultrasound (score 0-3 per joint) at baseline and after treatment. Two ultrasonographers blinded for clinical data scored the live images together (simultaneously) in real-time. A consensus score for each joint was recorded. Representative images stored during scanning were scored by one ultrasonographer minimally 6 months after real-time scoring. For each patient, images of each visit were scored paired, with known chronological order. Agreement between scoring methods was studied at joint level with quadratic weighted kappa. At patient level, intra-class correlations (ICC; mixed effect model, absolute agreement, with clustering taken into account) were calculated at both timepoints. ICCs were also calculated for the delta of sum scores. Responsiveness of scoring methods was analyzed with generalized estimating equations (GEE) with treatment as independent and ultrasonography findings as dependent variable. Results: Thirty-nine patients (52%) were treated with prednisolone and 36 (48%) were treated with placebo. Patient characteristics were well-balanced between treatment groups. All patients had signs of synovial thickening and osteophytes as assessed by real-time ultrasonography, and almost all signs of effusion (99%) or a positive Doppler signal (95%) in at least one joint. Total ultrasonography sum score for osteophytes was high (mean 45 ±SD 12), whereas sum score was low for positive Doppler signal (mean 5.9 ±SD 4.4), with intermediate sum scores for synovial thickening and effusion (mean 16 ±SD 6.3 and 11 ±SD 6.0 respectively). Static sum scores were overall slightly higher (osteophytes mean 48 ±SD 10; Doppler mean 6.9 S±D 5.0; synovial thickening mean 20 ±SD 7.0 and effusion 13 ±SD 6.5) Agreement at baseline was good to excellent at joint level (kappa 0.72-0.88) and moderate to excellent at patient level (ICC 0.59-0.86). Agreement for delta sum scores was poor to fair for synovial thickening and effusion (ICC 0.18 and 0.34 respectively), but excellent for Doppler signal (ICC 0.80) (Table 1). Real-time ultrasonography showed responsiveness to prednisolone with a mean between-group difference of synovial thickening sum score of -2.5 (CI:-4.7 to-0.3). Static ultrasonography did not show a decrease in synovial thickening (Figure 1). No difference in ultrasonography scores was seen for the other ultrasonography features, neither with real-time nor static scoring. Conclusion: While cross-sectional agreement between real-time and static ultrasonography was good, agreement of delta sum scores was not and paired static ultrasonography measurement of synovial thickening did not show responsiveness to prednisone therapy where real-time ultrasonography did. Therefore, when using ultrasonography in clinical trials, real-time dynamic scoring should remain the standard. Table 1. Agreement on patient level Baseline Week 6 Delta W6-BL ICC (95% CI) ICC (95% CI) ICC (95% CI) Synovitis 0.59 (0.26-0.76) 0.58 (0.24-0.77) 0.18 (0 - 0.40) Effusion 0.84 (0.66-0.92) 0.84 (0.75-0.89) 0.34 (0.12-0.53) Osteophytes 0.82 (0.50-0.92) 0.78 (0.56-0.88) ND Doppler 0.86 (0.75-0.92) 0.91 (0.85-0.94) 0.80 (0.70 -0.87) ICC: intra-class correlation coefficient linear mixed model (random patient, fixed rating), absolute agreement. ND: Not Dertermined Disclosure of Interests: Lotte van de Stadt: None declared, Féline Kroon: None declared, Monique Reijnierse Grant/research support from: Dutch Arthritis Foundation, Désirée van der Heijde Consultant of: bbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma, Frits Rosendaal: None declared, Naghmeh Riyazi: None declared, R. de Slegte: None declared, Jende van Zeben: None declared, Cornelia Allaart: None declared, Margreet Kloppenburg Consultant of: Abbvie, Pfizer, Levicept, GlaxoSmithKline, Merck-Serono, Kiniksa, Flexion, Galapagos, Jansen, CHDR, Grant/research support from: MI-APPROACH, Marion Kortekaas: None declared