Key clinical point: The Rheumatoid Arthritis Foot Disease Activity Index-5 (RADAI-F5) is a valid measure of foot disease in RA patients.

Major finding: The RADAI-F5 showed high levels of internal consistency and reproducibility, and 82% of participants reported it relevant and understandable.

Study details: The data come from 142 adults with rheumatoid arthritis.

Disclosures: No funding source was reported for the research study. The lead author reported receiving financial support from the Versus Arthritis Musculoskeletal Allied Health Professionals Internship Scheme.

Commentary

“Joints of the feet are commonly involved in patients with RA but are not commonly assessed in disease activity measures or joint counts, which may thus fail to capture a significant source of disability and pain. In this study, researchers developed and validated a new foot disease activity measure for people with RA, modified from the RA disease activity index (RADAI). The measure correlated well with the RADAI but not the DAS28-ESR, as expected given the derivation source. While this measure represents an important step in evaluating the importance of foot symptoms in patients with RA, a correlation to a different patient-reported outcome measure such as the health assessment questionnaire would help solidify this measure’s utility in addressing sources of disability and potential contributions from foot symptoms.”

Arundathi Jayatilleke, MD

Lewis Katz School of Medicine, Temple University