Validity and reliability study of the Turkish version of the Lower Extremity Functional Scale in elderly adults

BACKGROUND: The World Health Organization's disability and health model implicates activity limitation based on the International Classification of Functioning, Disability, and Health (ICF). The Lower Extremity Functional Scale (LEFS) was developed in the framework of the ICF to define the functional status of the lower extremities as an important indicator of the health, activity, and participation of the elderly. OBJECTIVE: To analyze the psychometric properties of the Turkish version of LEFS (LEFS-T) in older individuals. METHODS: A total of 214 older individuals were included in the study and the LEFS-T, Five-Times-Sit-to-Stand Test (FTSTS), and Falls Efficacy Scale-International (FES-I) were administered. Reliability and validity were evaluated according to Cronbach's alpha internal consistency coefficients (ICC), spearman correlation analysis, and confirmatory factor analysis (CFA). RESULTS: LEFS-T was feasible, had good internal consistency (0.93), good reliability (ICC = 0.98), good construct, and discriminant validity, and showed no floor or ceiling effects. The results of CFA are at excellent levels (Root Mean Square Error of Approximation = 0.004, Goodness of Fit = 0.974, Comparative Fit Index = 0.991, Non-Normed Fit Index = 0.990). For construct validity, LEFS-T showed a better correlation with FTSTS (r = -0.555, p < 0.001) and FES-I (r = -0.756, p < 0.001). CONCLUSION: The Turkish version of LEFS has good psychometric properties to evaluate functional capacity in older adults without lower extremity musculoskeletal disorders. LEFS-T can be used in future studies to evaluate and follow changes in lower extremity functional capacity as well as strength problems and fall prevention interventions, as it is a valid, reliable, and easily applicable scale with self-report.