AB0276 Comparison of health assessment questionnaire disability progression in rheumatoid arthritis patients with proposed sdai, cdai, and rapid3-based minimal disease activity and patients with low disease activity: results from a japanese national database

Background By OMERACT, a core-set definition of minimal disease activity (MDA) required a tender joint count (TJC) of 0, swollen joint count (SJC) of 0, and erythrocyte sedimentation rate (ESR) ≤10 mm/hour or the fulfilment of 5 of 7 core criteria, namely, pain ≤2, SJC≤1, TJC≤1, heath assessment questionnaire (HAQ) ≤0.5, physician’s global ≤1.5, patient’s global ≤2, and ESR ≤20.1 In addition to the original Disease Activity Score 28 (DAS28)-based MDA definition (DAS28 ≤2.85),1 we proposed a Simplified Disease Activity Index (SDAI)≤5.3, Clinical Disease Activity Index (CDAI) ≤4.8, and Routine Assessment of Patient Index Data 3 (RAPID3) ≤5, each value being two points higher than the respective remission criterion, as cut-offs for the MDA index in routine care for rheumatoid arthritis (RA).2 Objectives To compare HAQ disability progression in patients with proposed SDAI, CDAI, and RAPID3-based MDA and patients with low disease activity (LDA) for each index. Methods We evaluated RA patients with functional remission (HAQ≤0.5) registered with the Japanese National Database. We excluded patients with any missing values for patient SJC, TJC, physician’s global, patient’s global, pain, CRP, ESR, HAQ, or MDHAQ, which require the MDA to be assessed and the DAS28, SDAI, CDAI, and RAPID3 scores to be determined. HAQ disability progression from 2015 to 2016 was analysed in patients with MDA vs non-MDA and in those with LDA (or remission) vs non-LDA (or remission). The interclass correlation of the disease activity categories of LDA and MDA in DAS28, CDAI (SDAI), and RAPID3 were also compared. Results In total 3798 patients were analysed, 76.5% of whom met the core-set definition of MDA and 40.3% of whom were assessed as being in Boolean remission. Patients with a core-set definition of MDA had less HAQ progression over one year (356±71 days) than those without the core-set definition, at 0.036 (95% CI: 0.026–0.045) and 0,066 (0.050–0.082) (p=0.002), respectively. The progression of HAQ in each disease activity state is summarised in table 1. Patients in the DAS28, SDAI, CDAI, and RAPID3-based MDA group showed less HAQ progression. The same results were found for LDA. For the MDA categories, the interclass correlation for CDAI (SDAI) vs DAS28, CDAI (SDAI) vs RAPID3, and DAS28 vs RAPID3 was 0.585 (0.617), 0.568 (0.557), and 0.361, respectively, and 0.449 (0.442), 0.411 (0.410), and 0.371 for LDA, respectively. Conclusions Among patients with functional remission, both the MDA and LDA categories showed less HAQ progression over one year. The interclass correlation for MDA was more acceptable than that for LDA. Index-based MDA, which provides more stringent criteria than LDA, may serve as an alternative target for LDA in patients who have difficulty achieving remission. References [1] Wells GA, et al. J Rheumatol2005;32:2016–24. [2] Yokogawa N, et al. Ann Rheum Dis2017:76(supplement 2):525. Acknowledgements Supported in part by a Health and Labour Sciences Research Grant from the Ministry of Health, Labour, and Welfare of Japan Disclosure of Interest None declared