The concept of difficult-to-treat disease in rheumatology: where next?
New pathogenesis-based therapeutics and evidence-based consensus treatment recommendations, often with predefined treatment goals, have remarkably improved outcomes across many chronic diseases. However, a clinically significant subgroup of patients responds poorly to interventions and show a progressive decline in the disease trajectory, which poses an increasing health-care challenge. Difficult-to-treat approaches exist in several areas of medicine and the need for similar definitions has recently also emerged in rheumatology.
