RESUMEN
BACKGROUND: The lower extremity functional scale (LEFS) is a patient-reported outcome measure for assessment of lower extremity function. It has been validated in adults but not in children or adolescents. METHODS: Patients 8 to 18 years of age who were treated for a lower limb fracture, injury, or other conditions were invited to join the study. LEFS and Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL) were administered. Reliability and validity of the LEFS were determined for the entire cohort and for 2 age groups (children: 8 to 12 years; adolescents 13 to 18 years) using PedsQL as comparison. RESULTS: A total of 178 patients were recruited into this study. In the entire cohort, internal consistency of LEFS was excellent (0. 972) with acceptable floor (0%) and ceiling (12%) effects. Correlation between LEFS and PedsQL physical functioning component was high ( r =0.859). Construct validity was acceptable, with all 8 hypotheses demonstrating statistical significance. Factor analysis showed that item 15 (sitting for 1 hour) may contribute to measurement error in the pediatric population. Results remained similar when comparing the 2 age groups. CONCLUSIONS: The LEFS is overall an acceptable patient-reported outcome assessment of children and adolescents with various lower limbs disorders. LEVEL OF EVIDENCE: Level II.