To the Editors:

The goal of our editorial entitled Development of Classification and Response Criteria for Rheumatic Diseases, published in a recent issue of Arthritis Care & Research, was to help move forward rheumatic disease research (1). We regret, however, that in so doing we failed to acknowledge the many seminal contributions of OMERACT (Outcome Measures in Rheumatology) towards this end. Since its inception in 1992, OMERACT has met biennially to address issues of measurement of outcome in the rheumatic diseases. These meetings have produced many key publications closely related to the topic of our editorial (2–4). We want to publicly acknowledge the important contributions of OMERACT, and continue to build collaborations that will enable the science and practice of rheumatology to advance.

Jasvinder A. Singh MD, MPH*, Daniel H. Solomon MD, MPH*, Maxime Dougados MD*, David Felson MD, MPH*, Gillian Hawker MD, MPH*, Patricia Katz PhD*, Hal Paulus MD*, Jeffrey Siegel MD*, Carol Wallace MD*, * Classification and Response Criteria Subcommittee of the American College of Rheumatology Committee on Quality Measures.