Progress towards optimal trial end-points in rheumatoid arthritis

Trials in rheumatoid arthritis have been difficult to perform and interpret due to disagreement over what to measure. This paper reviews the most frequently used measures and their validity against the background of the Outcome Measures in Rheumatology (OMERACT) consensus conferences. These conferences have resulted in the adoption of a core set of end-points to be used as a minimum in all clinical trials in rheumatoid arthritis. These are known as the World Health Organization/International League of Associations for Rheumatology (WHO/ILAR) core set. This set of measures comprises: (i) pain; (ii) patient global assessment; (iii) physical disability; (iv) swollen joints; (v) tender joints; (vi) acute phase reactants; (vii) physician (assessor) global assessment; and, in studies of 1 or more years duration, (viii) radiographs of joints. Other developments include a renewed interest in aggregate end-points (indices) such as response criteria, and in the measurement of adverse effects and economic costs. In sum, measurement methodology in rheumatoid arthritis has been improved in time to take advantage of expected important advances in treatment.