Background For the assessment of disease activity in rheumatoid arthritis (RA), numbers of composite scores are available: Disease-Activity-Score in 28 joints (DAS28), the Simplified-Disease-Activity-Index (SDAI), and the Clinical-Disease-Activity-Score (CDAI). Baker et al. have recently developed a modified version of these scores based on widely available clinical measures (swollen joint count [SJC] evaluator global assessment of disease activity [EvGA] and CRP level). (1) These scores demonstrated superior correlation with MRI detection of synovitis and more accurately predicted radiographic progression after 1 year than DAS28 and SDAI.
Objectives To evaluate the performance of new composite disease activity scores (M-DAS28, M-SDAI and M-CDAI]) compared to conventional measures (DAS28, SDAI and CDAI) to predict radiographic progression in patients with early arthritis.
Methods This study was conducted on the French multicentric ESPOIR cohort including patients with early (<6 months) unclassified arthritis. The M-DAS28, M-SDAI, and M-CDAI were respectively compared to the DAS28, CDAI and SDAI with regard to associations of radiographic progression (estimated after 1 year by The Sharp/van der Heidje [SHS] scoring system) using t-Student or Mann-Whitney test and receiver operating characteristic analysis.
Results A total of 664 patients (women 77%, median age 48.6 years, median symptom duration 16 weeks) were included. The mean SJC was 7, the mean tender joint count was 8, the mean ESR was 29 mm/h, the mean CRP level was 21 mg/L. Radiographic progression (ΔSHS ≥1) was present in 60.1% after 1 year. A total of 568 patients (85%) fulfilled the ACR 1987 criteria for RA. The baseline M-DAS28-ESR and the DAS28-ESR both correlated to the same extent with the radiographic progression of joint damage at 1 year (respective area under the curve [AUC] of 0.55 [0.50-0.59] and 0.55 [0.51-0.60]). The baseline M-DAS28CRP also correlated with radiographic progression at 1 year (AUC 0.55 [0.51-0.60]) not the DAS-28-CRP (AUC 0.54 [0.49-0.58]). SDAI and M-SDAI had similar capacity to predict X-ray progression (AUC 0.53 [0.49-0.58] and 0.54 [0.50-0.59] respectively) and did not yeld statistical significance. The same was true for the CDAI versus the M-CDAI (AUC 0.53 [0.49-0.58] for both). A subgroup analysis on patients fulfilling the ACR 1987 criteria for RA has been performed without difference between the conventional and modified scores.
Conclusions We did not find significant differences between M-DAS28 vs. DAS28, M-CDAI vs. CDAI, and M-SDAI vs. SDAI to predict radiographic progression after 1 year in patients with early arthritis.
Baker JF, Conaghan PG, Smolen JS, Aletaha D, Shults J, Emery P, et al. Development and validation of modified disease activity scores in rheumatoid arthritis: Superior correlation with MRI synovitis and X-ray progression. Arthritis Rheum. 2014;66:794-802
Disclosure of Interest None declared