Strengths and limitations of the EULAR definition for difficult-to-treat rheumatoid arthritis.

The management of rheumatoid arthritis (RA) has significantly improved, but a substantial number of patients still experience persistent disease activity, leading to the concept of 'difficult-to-treat RA' (D2T RA). The European Alliance of Associations for Rheumatology (EULAR) has provided a pivotal definition for D2T RA to unify clinical approaches and research methods. This definition frames D2T RA as an umbrella term for a diverse group of patients with management challenges stemming from various factors, including biological resistance, patient experience, and clinical complexities. This framework is invaluable for a previously ill-defined population, but its real-life application highlights areas for ongoing consideration and potential refinement. Here, we discuss some of the strengths and limitations of the EULAR definition for D2T RA.