Updating the OMERACT filter at OMERACT 11.

The Outcome Measures in Rheumatology (OMERACT) community strives to develop core outcome sets for rheumatologic conditions to specify, for each condition, the minimum set of outcomes necessary to provide consistent estimates of the benefits of an intervention. The original and successful OMERACT filter of "truth, discrimination, and feasibility" requires development and updating because of application to a widening range of conditions by an expanding group, particularly patients. It should more explicitly identify the relevant core outcomes that might be universal to all randomized controlled trials within rheumatology. Working from first principles, comparing proposals against actual procedures adopted by OMERACT working groups, and seeking a broad consensus over several major sessions at the OMERACT 11 meeting, a new version has emerged, OMERACT Filter 2.0, which will form the central theme of the intended OMERACT handbook and offers an approach to core outcome set development in many areas of healthcare.