The added value of musculoskeletal ultrasound to clinical evaluation in the treatment decision of rheumatoid arthritis outpatients: physician experience matters

Abstract Background Musculoskeletal ultrasound improves the accuracy of detecting the level of disease activity (DA) in RA patients, although its impact on the final treatment decision in a real clinical setting is uncertain. The objectives were to define the percentage of clinical scenarios from an ongoing cohort of RA outpatients in which the German Ultrasound Score on 7 joints (GUS-7) impacted the treatment and to explore if the impact differed between a senior rheumatologist (SR) vs. a trainee (TR). Methods Eighty-five consecutive and randomly selected RA outpatients underwent 170 assessments, 85 each by the SR and the TR. Initially, both physicians (blinded to each other) performed a rheumatic assessment and recommended a preliminary treatment. Then, the patients underwent the GUS-7 evaluation by an experienced rheumatologist blinded to clinical evaluations; selected joints of the clinically dominant hand were assessed by gray-scale and power Doppler (PD). In the final step, the TR and the SR integrated the GUS-7 findings with their previous evaluation and reviewed their recommendations. The patients received the final recommendation from the SR to avoid patient confusion. The study was approved by the Internal Review Board and all the patients signed informed consent. GUS-7 usefulness was separately evaluated by the SR and the TR according to a visual analogue scale (0 = not useful at all, 10 = very useful). Descriptive statistics were used. Results The patients were primarily middle-aged females (91.4%) with (mean ± SD) disease duration of 7.5 ± 3.9 years. The majority of them (69.2% according to TR and 71.8% to SR) were in DAS28-ESR-remission. In 34 of 170 clinical scenarios (20%), the GUS-7 findings modified the final treatment proposal; 24 of these scenarios were determined by the TR vs. 10 by the SR: 70.5% vs. 29.5%, p = 0.01. Treatment changes (increase, decrease and joint injection) were similar between both specialists. As expected, the TR rated the GUS-7 usefulness higher than the SR, particularly in the clinical scenarios where the GUS-7 findings impacted treatment. Conclusions Musculoskeletal ultrasound added to standard rheumatic assessments impacted the treatment proposal in a limited number of patients; the impact was greater in the TR