To evaluate the inter- and intraobserver agreement of a group of European rheumatologist ultrasonographers in grading musculoskeletal ultrasound videoclips posted on the Internet by using a non-sophisticated electronic environment.
Forty short movie clips (less than 30 secs) were made available over the Internet to all participants. Normal and pathological RA hand joints and tendons were included in the movie clips. In the first phase 30 investigators from European countries were invited to evaluate the clips and to interpret/grade them. No instruction session was held prior to the initiation of the study. For synovitis the requested scoring system included 0 to3 grades and for tenosynovitis a binary variable 0/1; separate evaluations were performed for gray scale (GS) and Power Doppler (PD) examinations. In the second phase the responders were asked to grade the same clips in a different order without having access to their first grading scale. Light's k and Cohen's k were used to analyse inter- and intraobserver reliability.
Twenty two European rheumatologists agreed to finalise both study phases. Mean Cohen's κ for intraobserver reliability was 0.614/0.689 for tenosynovitis GS/PD and 0.523/0.621 for synovitis GS/PD. Light's k for interobserver reliability was 0.503 for tenosynovitis evaluation and 0.455 for global (synovitis and tenosynovitis) evaluation. Mean global overall agreement was 84.95% (90.2% for global synovitis).
An over-the-net US evaluation and grading has shown moderate to good reliability. The results could be improved if a training session is added at the beginning of the study.