Use of the International Classification of Functioning, Disability and Health (ICF) in Randomized Controlled Trials of Rheumatoid Arthritis Pharmacological Treatments: a Scoping Review

BackgroundRheumatoid arthritis (RA) is a chronic autoimmune disease affecting approximately 0.5-1.0% of the adult population and is a significant contributor of disability worldwide. While Phase III randomized controlled trials (RCTs) remain the gold standard for evaluating pharmacological treatments, they often fail to capture outcomes that reflect patients lived experiences, also referred to as functioning. The International Classification of Functioning, Disability and Health (ICF) Brief Core Set for RA offers a standardized, patient-centered framework for assessing functioning across relevant domains. ObjectiveTo examine the extent to which functioning-related outcomes in Phase III pharmacological RCTs for RA align with the ICF Brief Core Set for RA and to identify the most frequently represented functioning categories. MethodsA scoping review was conducted following PRISMA-ScR guidelines. Literature was searched in MEDLINE, EMBASE, and ClinicalTrials.gov from 2010 to 2025. Phase III RCTs evaluating pharmacological interventions in adult patients with RA were included. Functioning-related outcomes were extracted and mapped to ICF categories using standardized linking rules. ResultsOf 852 records screened, 91 met the inclusion criteria. Functioning was frequently assessed through patient-reported outcomes and composite clinical measures. The most commonly linked ICF categories included sensation of pain (b280) and mobility of joint functions (b710) from the body functions domain; walking (d450) and carrying out daily routine (d230) from the activities and participation domain; and structures of the shoulder (s720), upper (s730), and lower extremities (s740) from the body structures domain. However, none of the studies explicitly used the ICF framework. ConclusionFunctioning is implicitly assessed in RA pharmacological trials, yet the ICF framework remains underutilized. Explicit integration of the ICF Brief Core Set for RA into trial design could improve the standardization, comparability, and patient-centeredness of outcome measurement, ensuring that clinical research better reflects what matters most to individuals living with RA.