The Italian version of the Lower Extremity Functional Scale was reliable, valid, and responsive

Objective: To determine the measurement properties of an Italian Version of the Lower Extremity Functional Scale (LEFS) in patients with lower extremity musculoskeletal dysfunction. Study Design and Setting: This is a prospective methodological study of repeated measures with a sample of 250 consecutive patients. Reliability, validity, and responsiveness were evaluated. Results: The Italian version of the LEFS showed a high degree of internal consistency with a Cronbach alpha of 0.94 (95% confidence interval [CI]: 0.91, 0.96). The test-retest reliability was high for both intra-interviewer and inter-interviewer measures with an ICC_{(2,1 and 2,k)} of 0.91 (95% CI: 0.86, 0.93) and 0.89 (95% CI: 0.83, 0.91), respectively. The LEFS showed a better correlation with the 36-Item Short-Form Health Survey (SF-36) physical component summary score rather than with the SF-36 mental component summary score both at the initial assessment (r = 0.61 and 0.26, respectively) and at the discharge (r = 0.72 and 0.22, respectively). Receiver operating characteristic curve analysis revealed a large responsiveness for the LEFS (area under the curve [AUC] = 0.97) and a moderate responsiveness for the SF-36 (AUC = 0.68). Conclusion: The Italian version of the LEFS is a valid, reliable, and responsive tool that can be used to measure function in Italian patients with lower extremity musculoskeletal dysfunction.