Remission in rheumatoid arthritis: Which definition to use in the clinic?

Remission is the goal of treatment of rheumatoid arthritis today. However, no satisfactory definition of remission is available. A number of definitions have been used, viz. ACR, FDA, DAS, SDAI, CDAI, Clin28 (and Clin42), RAPID3 and Physician Global Assessment. FDA's definition is the most stringent definition currently because it demands not only the fulfilment of ACR criteria but also evidence of radiographic arrest by Larsen or modified Sharp's index while off all antirheumatic therapy. While DAS and its modifications require a computer software or a programmed calculator, CDAI avoids this requirement altogether. A serious drawback of all current definitions is the presence of residual disease activity in a significant proportion of patients meeting the criteria of “remission”. It appears that most definitions of remission identify a state of minimal disease activity (MDA)—a concept initially proposed by an OMERACT committee. Recently, it has been shown that a large proportion of patients deemed to be in clinical remission have evidence of active, ongoing disease process as revealed by MRI or ultrasound-power doppler studies. Perhaps, the best approach would be to aim at achieving a state of MDA first and then performing imaging studies to look for evidence of subclinical disease activity. If necessary, treatment should be escalated so that silent damage is prevented and deformities averted.