From Clinical Trials to Clinic: Making Sense of Rheumatology Metrics, with Roy Fleischmann, MD

Outcome measures are foundational to rheumatology research and care, but they are not interchangeable, and not all are equally useful at the bedside. Roy Fleischmann, MD, professor of medicine at the University of Texas Southwestern Medical Center in Dallas, sought to clear up confusion about the variety of rheumatology outcome measures currently used and calculating them in his talk at the 2026 Rheumatology Winter Clinical Symposium, held in Maui, Hawaii, on February 11–14.

RheumatologyLive sat down with Fleischmann to learn more about how outcome measures are used—and misused—across rheumatoid arthritis (RA), psoriatic arthritis (PsA), lupus, and axial spondyloarthritis. He emphasized that confusion persists among both clinicians and industry regarding which metrics belong in trials and which meaningfully inform clinical practice.

Certain composite scores, such as the Ankylosing Spondylitis Disease Activity Score (ASDAS), rely on formulas that require computational support. While the individual components can be obtained in clinic, calculating the score itself is not practical without digital tools. Other measures, though widely cited, are often misunderstood. In RA, for example, ACR20, ACR50, and ACR70 responses are essential in clinical trials, particularly for demonstrating superiority over placebo or comparing active agents. However, these metrics do not translate directly to day-to-day patient management and can be misleading when interpreted as indicators of real-world effectiveness.

Fleischmann stressed that clinicians should prioritize measures that reflect disease state and meaningful clinical change. In RA, the Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), and Boolean remission criteria provide clearer guidance for assessing low disease activity or remission. DAS28-ESR and RAPID3 may be used, though RAPID3 lacks specificity and may overestimate improvement.

In lupus, tools such as SLEDAI and lupus low disease activity state can offer practical insight, whereas more complex instruments like BILAG or BICLA are difficult to implement outside research settings. In PsA, Disease Activity in Psoriatic Arthritis (DAPSA) and minimal disease activity (MDA) are more feasible in practice than more elaborate composite scores. For axial disease, components of BASMI, BASFI, and pain assessments remain useful, even if no single metric is perfect.

“We have multiple outcome measures that can be used either in clinical practice or in clinical trials,” Flesichmann said. “There is great confusion, both by industry and by practitioners, as to which should be used. The other reason for the talk was, how do you really calculate the outcome measure?”

Reference

Fleischmann R. State of the Art: Outcome measures in Rheumatology. Presented at: RWCS 2026, held February 11-14 in Maui, Hawaii.