A global OMERACT ultrasound joint damage scoring system (GLODS) in rheumatoid arthritis

OBJECTIVES: This study aimed to develop consensual definitions and semiquantitative scoring for structural damage on ultrasound and to test the reliability of individual components of a global Outcome Measures in Rheumatology ultrasound joint damage score (GLODS) in rheumatoid arthritis (RA). METHODS: A Delphi survey including statements on normal ultrasound appearance of joint features, scanning technique, new definitions, and scoring systems for 3 components of structural damage (bone erosions, cartilage change, and joint malalignment) was circulated among task force members. After agreement (≥75% of grades 4-5 on a 1-5 Likert scale) was achieved on the statements, datasets of ultrasound images representing various grades of the above-mentioned structural damage components were created and used in 2 web-based exercises. Finally, the metacarpophalangeal joints 1 to 5 of 7 patients with RA were scanned with ultrasound, twice on the same day by 7 task force members for detecting and scoring the 3 components using the consensus-based semiquantitative GLODS. Intraobserver and interobserver reliability of the new scoring system was measured by weighted kappa. RESULTS: Agreement on a total of 9 statements was reached in 4 Delphi rounds. Intraobserver and interobserver reliability for the individual components ranged from good to excellent in both the web-based (0.72-0.97) and the live exercises (0.68-0.89). Intraobserver and interobserver reliability of the total GLODS was shown to be excellent (0.92) and good (0.69), respectively. CONCLUSIONS: Ultrasound is a reliable tool for evaluating bone erosions, cartilage change, and joint malalignment in the hand joints of patients with RA. These features can be reliably integrated into a global ultrasound score.