Background: Reducing the dose of biological therapy (BT) when patients with immune-mediated arthritis achieve a sustained therapeutic goal may help to decrease costs for national health services and reduce the risk of serious infection. However, there is little information about whether such a decision can be applied universally. Therefore, the objective of this study was to develop appropriateness criteria for reducing the dose of BT in patients with rheumatoid arthritis (RA), axial spondyloarthritis (axSpA), and peripheral spondyloarthritis (pSpA). Methods: The RAND/UCLA appropriateness method was coordinated by experts in the methodology. Five rheumatologists with clinical research experience in RA and/or SpA selected and precisely defined the variables considered relevant when deciding to reduce the dose of BT in the 3 diseases, in order to define patient profiles. Ten rheumatologists with experience in prescribing BT anonymously rated each profile on a scale of 1 (completely inappropriate) to 9 (completely appropriate) after revising a summary of the evidence obtained from 4 systematic literature reviews carried out specifically for this project. Findings: A total of 2,304 different profiles were obtained for RA, 768 for axSpA, and 3,072 for pSpA. Only 327 (14.2%) patient profiles in RA, 80 (10.4%) in axSpA, and 154 (5%) in pSpA were considered appropriate for reducing the dose of BT. By contrast, 749 (32.5%) patient profiles in RA, 270 (35.3%) in axSpA, and 1,243 (40.5%) in pSpA were considered inappropriate. The remaining profiles were considered uncertain. Interpretation: Appropriateness criteria for reducing the dose of BT were developed in 3 inflammatory conditions. These criteria can help clinicians treating these disorders to optimize the BT dose. However, further research is needed, since more than 50% of the profiles were considered uncertain and the real prevalence of each profile in daily clinical practice remains unknown.
