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

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).

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.

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.

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.