Reliability and validity of the Turkish version of the Lower Extremity Functional Scale in patients with different lower limb musculoskeletal dysfunctions

Abstract

Background/Aims Lower extremity functional scales in Turkish are limited in number and generalisability. The aims of this study were to translate the Lower Extremity Functional Scale into Turkish, and to investigate its reliability and validity in patients with different musculoskeletal conditions in their lower extremities. Methods The Turkish Lower Extremity Functional Scale, Visual Analogue Scale and Timed Up and Go test were administered in 256 outpatients with a re-test after 24-48 hours. Internal consistency, test-retest reliability, construct validity, factor structure and floor-ceiling effects were investigated. Findings The Scale has good reliability and validity. The Spearman correlation coefficient was 0.91 and intraclass correlation coefficient was 0.923. The standard error of measurement value was 4.015 and internal consistency coefficient was 0.92. Item-total correlation values were 0.46-0.74. It had a 3-factor structure, explaining 58.51% of the total variance and the eigenvalues were 1.04-8.26. It had no floor and ceiling effects, and was negatively correlated with the Visual Analogue Scale and Timed Up and Go test (P=0.000). Conclusions The Turkish Lower Extremity Functional Scale is a reliable and valid tool to be used in participants with lower extremity musculoskeletal dysfunctions. Evaluation of its responsiveness and minimal clinically important difference in future studies would have a great value.