Study protocol for the validation of a new pictorial functional scale in patients with knee osteoarthritis: the functional activity scoring tool (FAST)

Abstract

BackgroundPatient-reported outcome measures (PROMs) are required for patient-centred care. There are limited PROMs with good psychometric properties, and limitations to any language-based scale are often constrained by the written words or numerals used. Therefore, we developed the Functional Activity Scoring Tool (FAST), a self-reporting pictorial scale. FAST measures the impact of knee osteoarthritis on essential activities of daily living (ADL) and the significant changes in the self-perceived functional status over time.ObjectivesThis study aims to (1) develop FAST with adaptation from the Wong-Baker FACES pain rating scale, (2) validate FAST against the Patient-Specific Functional Scale (PSFS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) and (3) establish the reliability, validity and responsiveness of FAST in individuals with knee osteoarthritis.Methods and analysisThe prospective study protocol investigates the validity, responsiveness and reliability of FAST. The PSFS and KOOS will be gold standard comparisons. Participant recruitment will occur at four public polyclinics that offer physiotherapy outpatient services in Singapore. Onsite physiotherapists familiar with the study eligibilities will refer potential participants to the investigators after the routine physiotherapy assessment. After providing written consent, eligible participants will complete outcome measurements with FAST, the PSFS and KOOS during baseline and follow-up assessments. The Global Rating of Change (GROC) scale will determine how the participant’s knee status was changed compared with the beginning of the physiotherapy intervention.Ethics and disseminationSingHealth Centralised Institutional Review Board approved the study (CIRB reference number: 2022/2602). The final results will be published via scientific publication. FAST will benefit the evaluation and management of those who suffer knee osteoarthritis regardless of English proficiency or language barriers.Trial registration numberNCT05590663