To the Editor:
I read the paper by Yoshida, et al1 involving 2 cohort studies from the United States and Japan to determine the predictors of discontinuation of biological disease-modifying antirheumatic drugs (bDMARD) in patients with rheumatoid arthritis (RA) while in remission over 5 years, defined by the Clinical Disease Activity Index (CDAI) ≤ 2.8. The authors used Cox regression models, and the percentages of discontinuation of bDMARD were 10.0% and 11.8% from 6263 patients in the United States and …
Address correspondence to Dr. T. Kawada, Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan. E-mail: kawada{at}nms.ac.jp