title: Ultrasound evaluation of synovitis in RA: correlation with clinical disease activity and sensitivity to change in an observational cohort study.
abstract: OBJECTIVE
  To evaluate the correlation between clinical measures of disease activity and a ultrasound (US) scoring system for synovitis applied by many different ultrasonographers in a daily routine care setting within the Swiss registry for RA (SCQM) and further to determine the sensitivity to change of this US Score.
  
  
  METHODS
  One hundred and eight Swiss rheumatologists were trained in performing the Swiss Sonography in Arthritis and Rheumatism (SONAR) score. US B-mode and Power Doppler (PwD) scores were correlated with DAS28 and compared between the clinical categories in a cross-sectional cohort of patients. In patients with a second US (longitudinal cohort), we investigated if change in US score correlated with change in DAS and evaluated the responsiveness of both methods.
  
  
  RESULTS
  In the cross-sectional cohort with 536 patients, correlation between the B-mode score and DAS28 was significant but modest (Pearson coefficient r = 0.41, P < 0.0001). The same was true for the PwD score (r = 0.41, P < 0.0001). In the longitudinal cohort with 183 patients we also found a significant correlation between change in B-mode and in PwD score with change in DAS28 (r = 0.54, P < 0.0001 and r = 0.46, P < 0.0001, respectively). Both methods of evaluation (DAS and US) showed similar responsiveness according to standardized response mean (SRM).
  
  
  CONCLUSIONS
  The SONAR Score is practicable and was applied by many rheumatologists in daily routine care after initial training. It demonstrates significant correlations with the degree of as well as change in disease activity as measured by DAS. On the level of the individual, the US score shows many discrepancies and overlapping results exist.
authors.affiliation: RHU/CHUV, Lausanne, Switzerland. Electronic address: Pascal.zufferey@chuv.ch.
authors.forename: Pascal
authors.initials: P
authors.lastname: Zufferey
authors.affiliation: Rheumatology/HUG, Geneva, Switzerland.
authors.forename: Laure
authors.initials: L
authors.lastname: Brulhart
authors.affiliation: Bethesda Spital AG. Basel, Switzerland.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Tamborrini
authors.affiliation: Rheumatology/HUG, Geneva, Switzerland.
authors.forename: Axel
authors.initials: A
authors.lastname: Finckh
authors.affiliation: SCQM, Zurich, Switzerland.
authors.forename: Almut
authors.initials: A
authors.lastname: Scherer
authors.affiliation: Rheumatology Inselspital, Bern, Switzerland.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Moller
authors.affiliation: OsteoRheuma Bern, Bahnhofplatz 1, Bern, Switzerland.
authors.forename: Hans-Rudolf
authors.initials: HR
authors.lastname: Ziswiler
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000628:therapy; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012042:Registries; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013557:Switzerland; D013585:Synovitis / Q000000981:diagnostic imaging* / Q000628:therapy; D014463:Ultrasonography
keywords: Disease activity; Rheumatoid arthritis; Synovitis; US