Background Various composite outcome measures have been developed in the last decade to evaluate Rheumatoid Arthritis (RA) activity, and the focus was in how to assess remission. The Ultrasonography (US) appears to be the best way to define remission but it is not always available.
Objectives Our aim from this study was to investigate the accuracy of composite scores in classifying RA patients who were in remission using the absence of inflammatory activity detected by ultrasound (US) as a gold standard.
Methods Sixty two patients followed up for RA were prospectively recruited. Among them, we identified patients in remission according to the Disease Activity Index 28 joints ≤2,6 (DAS28), the Simplified Disease Index ≤3,3 (SDAI), the Clinical Disease Index ≤2,8 (CDAI) and the American College of Rheumatology/European League Against Rheumatology (ACR/EULAR) 2011 criteria. B-mode and a Power Doppler (PD) US exam were assessed by a single rheumatologist who was experienced in US and blinded to the clinical and laboratory data. Twenty two joints were scanned (wrists, 10 metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints). Sensitivity, specificity and Positive Predictive value (PPV) for each score were calculated with as reference absence of Doppler signals in US.
Results Among 62 patients screened, 30 (48%) were in remission according to the DAS28, 19 (31%) according to SDAI, 26 (42%) according to CDAI and 14 (23%) when new ACR/EULAR criteria were accomplished. Between all patients with active or not RA, nineteen had no Doppler signals in US. Considering “remission” to be the absence of joints with PD signal, the DAS28 was the most sensitive score while the ACR/EULAR criteria were the most specific. We resumed in table 1 our outcomes of sensitivity, specificity and PPV for each score of remission.
Conclusions Ours results suggest that when considering remission as an absence of Doppler signal, the sensitivity of DAS28 was better than SDAI, CDAI and ACR/EULAR definitions of remission. While the ACR/EULAR criteria were the most specific.
Balsa A, De Miguel E and col. Superiority of SDAI over DAS-28 in assessing remission in rheumatoid arthritis patients using power Doppler ultrasonography as a gold standard. Rheumatology 2010.
Disclosure of Interest None declared