Progress in measurement instruments for acute and chronic gout studies.

Consensus exercises have identified and prioritized domains of measurement for studies in acute and chronic gout. In parallel, the technical properties of instruments for measurement in many of these domains have been assessed, with the main objective to consider the instruments in the context of the OMERACT filter of truth, discrimination, and feasibility. These data were presented and discussed at OMERACT 9 in the gout workshop, in breakout groups, and at informal meetings of the gout group. In acute gout, instruments for domains of pain, joint swelling, joint tenderness, and patient and physician global assessment have been assessed. In chronic gout, some validation exercises have been performed in instruments for domains serum urate, tophus measurement, health-related quality of life (HRQOL). In voting at OMERACT 9, the Medical Outcomes Study Short-Form 36 was endorsed as a valid instrument for measurement of HRQOL. Methods of tophus measurement were considered to have met some criteria of the OMERACT filter, but these require further work, particularly regarding sensitivity to change over shorter time periods. Priorities for future research include measurement of joint inflammation in acute gout and disability in acute and chronic gout.