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

Abstract 

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.

Keywords: Lower Extremity Functional Scale (LEFS), Validity, Reliability, Responsiveness, Cross-cultural, Disability