To the Editor: We agree strongly with Kremer et al that “metrics are essential for evaluating disease activity in patients with rheumatoid arthritis (RA).”1 Nonetheless, data reported from the Corrona and the Brigham and Women’s Rheumatoid Arthritis Sequential Study (BRASS) registries for Clinical Disease Activity Index (CDAI) and Routine Assessment of Patient Index Data 3 (RAPID3) are quite similar to those reported in the initial 2008 RAPID3 report.2 In the Corrona, BRASS, and 2008 RAPID3...