This evidence note examines recent findings from a network meta-analysis of 31 randomized controlled trials evaluating csDMARD monotherapy in rheumatoid arthritis. The analysis shows that several agents, including leflunomide and sulfasalazine, demonstrate effects on radiographic progression comparable to methotrexate. These results are typically interpreted as evidence of stable treatment equivalence across therapies. However, such conclusions are based on aggregated outcomes across heterogeneous patient populations and disease stages. This note proposes a state-dependent interpretation of treatment response, where therapeutic effects vary according to the underlying system state and disease trajectory. From this perspective, apparent equivalence at the population level may obscure clinically relevant variation related to timing, system stability, and responsiveness. The aim is not to challenge the validity of the reported findings, but to extend their interpretation by introducing a dynamic framework for understanding treatment effects in rheumatoid arthritis. This approach has implications for clinical decision-making, particularly regarding timing of intervention and interpretation of treatment response.
Anita Domargård (Sat,) studied this question.