THU0086 FACTORS ASSOCIATED WITH TREATMENT RESPONSE IN PATIENTS WITH ELDERLY-ONSET RHEUMATOID ARTHRITIS: 3-YEAR OBSERVATION USING THE IORRA COHORT.

Abstract

Background:Patients with elderly-onset rheumatoid arthritis (EORA) are on the rise in the aging or super-aging society, especially in Japan. Patients with EORA have more comorbidities than those with younger-onset RA, a higher risk of adverse drug reactions due to reduced drug metabolism, and a higher risk of infections1). Therefore, patients with EORA tend to receive suboptimal treatment, resulting in insufficient control of disease activity2). Although several studies reported treatment responsiveness in patients with EORA, many of them have a limited observation period3-8), and long-term treatment responses and their associated factors need to be clarified.Objectives:We retrospectively evaluated treatment responses of patients with EORA for 3 years and their associated factors in a clinical setting.Methods:The Institute of Rheumatology Rheumatoid Arthritis (IORRA) cohort is a large, single institute-based, observational cohort of RA patients established at Institute of Rheumatology, Tokyo Women’s Medical University, in 2000. The subjects were RA patients who first enrolled in the IORRA cohort from 2010 to 2014, were over 60 years old with less than 1-year disease duration, and had a DAS28-ESR over 3.2 at entry. The primary endpoint was DAS28-ESR <3.2 after 3-year observation. A multivariate logistic regression analysis was conducted to identify factors at baseline associated with the primary endpoint. The missing values of DAS28-ESR were imputed by using the last observation carried forward method.Results:Among a total of 250 patients in this study, 152 patients (60.8%) achieved DAS28-ESR <3.2 after 3-year observation (remission/low disease activity (RL) group), and 98 patients did not (moderate/high disease activity (MH) group). Baseline characteristics of the patients were as follows (average ± SD or %): the RL group, age 69.9 ± 6.5, female 77%, DAS28-ESR 4.3 ± 0.8, J-HAQ 0.9 ± 0.7, PSL user 23.7%, MTX user 64.5%, and biologics user 4.0%; the MH group, age 69.4 ± 6.7, female 80.6%, DAS28-ESR 4.4 ± 0.8, J-HAQ 1.0 ± 0.7, PSL user 36.7%, MTX user 64.3%, and biologics user 6.1%. Proportions of the patients with cardiovascular disease and malignancy were 13.3% and 11.2% in the MH group and 5.9% and 1.3% in the RL group, respectively. DAS28-ESR and J-HAQ score after 3-year observation of the RL group were 2.3±0.5 and 0.4±0.5, respectively, and those of the MH group were 3.4±0.9 and 1.0±0.8, respectively. Corticosteroid use and having malignancy at baseline were associated with not achieving DAS28-ESR <3.2 after 3-year observation using multivariate analysis (Table 1). Similar results were obtained when MTX use and corticosteroid use were replaced by the average dose of each drug.Conclusion:The majority of the patients with EORA achieved DAS28-ESR <3.2 after 3-year observation, and no use of corticosteroid and absence of malignancy at baseline were associated with the good outcome.