Background Remission is considered a therapeutic target in the management of patients with rheumatoid arthritis (RA). In 2010, new remission criteria were proposed by ACR/EULAR to achieve better patient outcomes. We have previously shown that, in RA patients, these new remission criteria resulted in better functional outcomes than those associated with DAS28 remission. Nevertheless, progressive functional impairment still occurred in a few patients who maintained the new ACR/EULAR remission criteria.
Objectives To evaluate clinical factors associated with the progression of functional impairment in Japanese RA patients who successfully maintained the new ACR/EULAR remission criteria, based on the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort in our institute.
Methods We established the IORRA cohort, a large observational cohort of RA patients, in our institute beginning in October 2000. Clinical parameters were collected biannually (in April and October). RA patients who were in DAS28 remission in April 2008 (baseline) and those who completed all IORRA assessments every 6 months from April 2008 to October 2010 (6 data collections) were selected for this study. All patients were evaluated based on whether they achieved the new ACR/EULAR remission criteria at each data collection. Functional disability was assessed by J-HAQ, the validated Japanese version of HAQ. The remission criteria of the Boolean trial were used as the new ACR/EULAR remission criteria. Patients who met the Boolean trial remission criteria for more than 5 times were identified as those who maintained the Boolean trial remission criteria. Changes in the J-HAQ score between October 2010 and April 2008 were assessed for these patients. The differences in baseline clinical characteristics between patients whose J-HAQ score increased and those with unchanged or decreased scores were statistically analysed by logistic regression analysis. The receiver operating characteristic (ROC) curve was used to calculate the cut-off point at baseline to assess significant changes in J-HAQ scores.
Results A total of 916 RA patients in DAS28 remission at baseline completed all IORRA data collections in the succeeding 2.5 years. Among them, 248 patients maintained the Boolean trial remission criteria (female, 76.2%; mean age, 59.6 years; mean RA disease duration, 10.4 years; mean DAS28, 1.9; mean J-HAQ score, 0.09). Twenty-five of them had increase in the J-HAQ scores, and their mean J-HAQ score in October 2010 was 0.50. Simple regression analysis showed that the increase in the J-HAQ score was significantly correlated with a longer RA disease duration (p<0.01) and higher baseline J-HAQ score (p<0.01). Multiple regression analysis also confirmed that the increase in the J-HAQ score was significantly correlated with these two baseline variables (p<0.05). The cut-off point at baseline for RA disease duration was 12 years, whereas that for the J-HAQ score was 0.125.
Conclusions To prevent functional impairment even in patients who maintain the ACR/EULAR remission criteria, it would be important to maintain the Boolean trial remission criteria before functional impairment occurs.
Disclosure of Interest K. Ochi: None Declared, E. Tanaka: None Declared, K. Shidara: None Declared, K. Ikari: None Declared, A. Nakajima: None Declared, A. Taniguchi: None Declared, S. Momohara: None Declared, H. Yamanaka Speakers bureau: Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Wyeth K.K., Daiichi Sankyo Co., Ltd., Banyu Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Abbott Japan Co., Ltd., Eisai Co., Ltd., Santen Pharmaceutical Co., Ltd., Taishotoyama Pharmaceuti, 2, Abbott, Eisai Co., Ltd., Takeda Pharmaceutical Company Limited, Mitsubishi Tanabe Pharma Corporation, Janssen Pharmaceutical K.K., Hoffmann-La Roche, Chugai Pharmaceutical Co., Ltd, Pfeizer Inc.