Validação da Lower Extremity Functional Scale com 10 itens (LEFS-10) português do Brasil para indivíduos com osteoartrite de joelho

Abstract

Objective: To validate the Brazilian Portuguese version of the Lower Extremity Functional Scale - 10 (LEFS-10) in individuals with knee osteoarthritis (KOA). Materials and Methods: This methodological study aimed to analyze the measurement properties of a Patient Reported Outcome Measure (PROM). The study was conducted according to the Guidelines for the Process of Cross-cultural Adaptation of Self-Report Measures and the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). Participants included individuals of both genders, aged 40 years or older, with a confirmed medical diagnosis of knee OA, complaints of pain and/or functional impairment in the lower limbs for 12 weeks or more, morning stiffness, pain intensity of three or higher on the Numeric Pain Rating Scale (NPRS), Kellgren-Lawrence grade 2 or 3 on knee X-ray, and fluency in Brazilian Portuguese. The psychometric properties evaluated included construct validity via Spearman's correlation coefficient (rho), assessing the correlation strength of the shortened version of the LEFS-10 with the Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the NPRS, and the World Health Organization Disability Schedule (WHODAS); criterion validity by analyzing the correlation between the shortened (LEFS-10) and the full version of the Lower Extremity Functional Scale (LEFS-20); test-retest reliability through the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC); internal consistency through Cronbach’s alpha; and ceiling and floor effects. Results: One hundred individuals with KOA were included for validity analysis, and a subsample of the last 50 individuals was used for test-retest reliability. Adequate reliability and internal consistency were observed, with ICC values ≥ 0.98 and Cronbach's alpha ≥ 0.89. For construct validity, correlations above 0.60 were observed with WOMAC, NPRS, and WHODAS. The shortened LEFS-10 version showed a correlation of ≥ 0.90 with the full version and did not exhibit ceiling or floor effects. Conclusion: The shortened LEFS-10 version has adequate measurement properties for assessing functionality in Brazilian individuals with knee osteoarthritis.