Outcome measures in rheumatoid arthritis

Traditional treatment with conventional Disease Modifying Anti-Rheumatic Drugs (DMARDs) for Rheumatoid Arthritis (RA) aim to suppress inflammation, relieve symptoms and retard joint destruction. Because of the limited efficacy and high risk of toxicity of current treatments, better treatments are needed. For assessing therapeutic efficacy and safety of any new treatment, clinical trials remain the gold standard. In clinical trials, outcome measures are the key tools that allow the impact of any intervention be assessed and compared. Before 1990, RA clinical trials often included 10 or more measures of disease activity. Over the past 20 years, OMERACT has played a critical role in driving global consensus on the development and validation of outcome measures in RA. The RA core data set includes 7 + 1 domains (pain, patient global assessment, physical disability, swollen joints, tender joints, acute phase reactants, physician/assessor global assessment, radiographs of joints), which should be assessed in all RA clinical trials. ACR Response Criteria, DAS28 and EULAR Response Criteria are the composite measures used in RA clinical trials globally. Fatigue was added to core data set after OMERACT 8 meeting with a major input from RA patients. OMERACT RA flare group is currently working on developing definition of RA flare. The RA core data set and response criteria had a fundamental impact on clinical trials, and are accepted by regulatory authorities in the licensing of new medications. They have become the global standard and used consistently in all clinical trials enabling pooling and comparing different clinical trials to facilitate evidence based practice.