Welcome to OMERACT
OMERACT (Outcome Measures in Rheumatology) is an independent initiative of international health professionals interested in outcome measures in rheumatology. Over the last 20 years, OMERACT has served a critical role in the development and validation of clinical and radiographic outcome measures in rheumatoid arthritis, osteoarthritis, psoriatic arthritis, fibromyalgia, and other rheumatic diseases.

Agreement regarding the use of standardized endpoints in randomized controlled trials and longitudinal observational studies is extremely important. Their use facilitates comparisons of outcomes across studies to provide the best estimates of benefit and safety of therapeutic interventions across differing patient populations.

OMERACT is coordinated by an executive committee and supervised by a steering committee. Consensus conferences take place every two years, with locations alternating between North America, Europe, and Asia-Pacific.

OMERACT works under the aegis of the International League for Rheumatology (ILAR) and the auspices of the World Health Organization (WHO). Additionally, OMERACT is linked to the Cochrane Collaboration Musculoskeletal Review Group where the outcomes endorsed by OMERACT are recommended for use in Cochrane Systematic Reviews.

The OMERACT Executive Committee is made up of worldwide independent investigators interested in outcomes research who receive no compensation from OMERACT for any activity. Individual members voluntarily undertake administrative and scientific responsibilities to advance the goals and activities of OMERACT.

The OMERACT Process
OMERACT strives to improve endpoint outcome measurement through a data driven, iterative consensus process involving relevant stakeholder groups.

The work of OMERACT is facilitated by participants within various working groups who provide input on the development of the OMERACT research agendas. The individual research agendas focus on measurement issues considering Truth, Discrimination and Feasibility, the backbone of the OMERACT Filter.

A powerful and important aspect of OMERACT is the integration of patients at each stage of the OMERACT process. This patient input along with clinical trialist insight, epidemiologist assessment, and industry perspective, has led OMERACT to be a unique decision making group in developing outcome measures for all types of clinical trials and observational research.

How Did OMERACT Start?
The first OMERACT conference on rheumatoid arthritis was held in Maastricht, the Netherlands in 1992. The motivation for this were discussions between 2 of the executive

Is the measure truthful, does it measure what it intends to measure? Is the result unbiased and relevant? This criterion captures the issues of face, content, construct and criterion validity.

Does the measure discriminate between situations that are of interest? The situations can be states at one time (for classification or prognosis) or states at different times (to measure change). This criterion captures the issues of reliability and sensitivity to change.

Can the measure be applied easily, given constraints of time, money, and interpretability? This criterion addresses the pragmatic reality of the use of the measure, one that may be decisive in determining a measure’s success.