Association of seventeen definitions of remission with functional status in a large clinical practice cohort of patients with rheumatoid arthritis

Objective To compare the association between different remission criteria and physical function in rheumatoid arthritis patients followed in clinical practice. Methods Longitudinal data from the METEOR database were used. Seventeen definitions of remission were tested: ACR/EULAR Boolean-based; Simplified/Clinical Disease Activity Index (SDAI/CDAI); and fourteen Disease Activity Score (DAS)-based definitions. Health Assessment Questionnaire (HAQ)≤0.5 was defined as good functional status. Associations were investigated using generalised estimating equations (GEE). Potential confounders were tested and sensitivity analyses performed. Results Data from 32,915 patients (157,899 visits) were available. The most stringent definition of remission was the ACR/EULAR Boolean-based definition (1.9%). The proportion of patients with HAQ≤0.5 was higher for the most stringent definitions, although it never reached 100%. However, this also meant that, for the most stringent criteria, many patients in non-remission had HAQ≤0.5. All remission definitions were associated with better function, with the strongest degree of association observed for the SDAI (adjusted OR (95% CI): 3.36 (3.01-3.74)). Conclusion The seventeen definitions of remission confirmed their validity against physical function in a large international clinical practice setting. Achievement of remission, according to any of the indices may be more important than the use of a specific index. A multidimensional approach, targeted at wider goals than disease control, is necessary to help all patients achieve the best possible functional status.