Background Tender and swollen joints count (TJC and SJC) are necessary to calculate the disease activity score DAS28 and to appreciate rheumatoid arthritis (RA) activity. Their accounting is very subjective and may differ between clinicians especially in wrist and hands joints. Ultrasound is excellent in detecting swollen joints.
Objectives To evaluate correlation of TJC and SJC in wrists and hands between three rheumatologists with different practicing years experience. To evaluate correlation between SJC of each rheumatologist and sonography count. To assess their impact on DAS28 and the correlation between the DAS28 of each rheumatologist and ultrasound-DAS28.
Methods We included 35 patients fulfilling the 1987 ARA criteria for RA. Each patient was examined (in double blinded) by 3 rheumatologists differing by their years of experience (Rheumatologist1=3 years, Rheumatologist2=7 years and Rheumatologist3=15 years). Within 2 hours of the clinical exam, sonography of the wrists, metacarpo-phalangeal, and proximal interphalangeal joints was performed. Synovial hypertrophy and/or joint effusion (SH/E) and power Doppler signal were identified in each joint for presence or absence. The approval of wrists and hands TJC and SJC between the three clinicians, then of the SJC between clinicians and ultrasound was assessed by calculating the correlation coefficient (CC). DAS28 of each clinician and ultrasound-DAS28 was calculated and the correlation was determined using the CC.
Results There were 29 women and 7 men. Age ranged from 34 to 71 years with a mean age of 53,5 years. The mean disease duration was 8,6 years. Patients were receiving Methotrexate (77,1%), leflunomide (11,4%), rituximab (8,5 %), Sulfasalazine (5,7%). 74,2% of patients was receiving 6,5 mg/day mean dose of prednisone. The TJC in wrists and hands joints was highly correlated between the three physicians. The CC was between 0,794 and 0,889. Wrists and hands SJC evaluation was correlated between the 3 Rheumatologits, this correlation was moderate (CC=0,503-0,681). Only Rheumatologist2 and Rheumatologist3 wrists and hands SJC was correlated with sonography count, the CC was low (0,481 and 0,491). The higher CC with ultrasound was seen with Rheumatologist 3 (who has more years experiences). The correlations between the DAS-28 of each rheumatologist and the ultrasound-DAS28 was excellent (CC was respectively 0,946, 0,948 and 0,951).
Conclusions Correlation between rheumatologists was good in wrists and hands TJC determination and moderate in SJC. In contrast, the correlation of Rheumatologists SJC and ultrasound was low and depending on clinician experience. However, due to the importance of the other items in the calculation of the DAS28, DAS28 correlation between the 3 clinicians and between DAS28-ultrasound was excellent.
Disclosure of Interest None Declared