Objective: The objective of this study was to compare disease activity assessed by the patient, the physician and musculoskeletal US in patients with RA in clinical remission.
Methods: We evaluated 69 patients with RA in clinical remission according to their attending rheumatologist. Tenderness and swelling in 28 joints were blindly assessed by patients and physicians. The presence of B-mode and Doppler synovitis was blindly investigated in the above joints. The DAS28 and Simplified Disease Activity Index (SDAI) were calculated.
Results: The percentage of patients in remission according to the self-derived DAS28 (26.1%) was significantly less than that according to the physician-derived DAS28 (52.2%) (P < 0.0005). There was no significant difference in the percentage of patients in remission according to the self-derived SDAI (14.5%) and the physician-derived SDAI (11.6%) (P = 0.172). We found moderate agreement between the patient-derived and physician-derived DAS28 and SDAI [intraclass correlation coefficient (ICC) = 0.620 and ICC = 0.678, respectively]. Agreement between patient and physician was better for the tender joint count (TJC; ICC = 0.509) than for the swollen joint count (SJC; ICC = 0.279). The mean (S.D.) count for B-mode synovitis [4.09 (3.25)] was significantly greater than the SJC assessed by both the patient and physician [2 (3.71) and 1.42 (2.03), respectively] (P < 0.0005 and P = 0.033, respectively). We found moderate agreement between the physician-assessed SJC and the joint count for Doppler synovitis (ICC = 0.528).
Conclusion: Patient-assessed and physician-assessed overall RA activity showed acceptable agreement. Patient self-assessment overestimated disease activity determined by the DAS28. At the patient level, physician-assessed joint swelling showed an acceptable concordance with Doppler US synovitis.
Keywords: patient assessment; physician assessment; remission; rheumatoid arthritis; ultrasound.