The Spanish lower extremity functional scale: A reliable, valid and responsive questionnaire to assess musculoskeletal disorders in the lower extremity

• Published in: Disability and rehabilitation 2014-11, Vol.36 (23), p.2005-2011
• Main Authors: Cruz-Díaz, David, Lomas-Vega, Rafael, Osuna-Pérez, María Catalina, Hita-Contreras, Fidel, Fernández, Ángeles Díaz, Martínez-Amat, Antonio
• Format: Article
• Language: English
• Subjects: Adult; Aged; Cross-Cultural Comparison; Cross-Sectional Studies; Disability Evaluation; Female; Humans; Lower Extremity - physiopathology; Lower extremity functional scale; Male; Middle Aged; Musculoskeletal Diseases - diagnosis; Musculoskeletal Diseases - psychology; Musculoskeletal Diseases - rehabilitation; Psychometrics; Recovery of Function; reliability; Reproducibility of Results; ROC Curve; Severity of Illness Index; Spain; Spanish version; Surveys and Questionnaires; Translations; Treatment Outcome; validity
• ISSN: 0963-8288; 1464-5165
• DOI: 10.3109/09638288.2014.890673

Abstract Purpose: The Lower Extremity Functional Scale (LEFS) is a widely used questionnaire to evaluate the functional impairment of a patient with a disorder of one or both lower extremities. It also can be used to monitor the patient over time and to evaluate the effectiveness of an intervention. Nevertheless there is no Spanish version of the LEFS, so the aim of this study was the translation and cross-cultural adaption of the Spanish version of the LEFS and to evaluate its psychometrics properties. Methods: The questionnaire was cross cultural adapted into Spanish. The psychometric properties tested in the Spanish version of the LEFS were: internal consistency, test-retest reliability, constructs validity, discriminative validity, responsiveness, concurrent validity and floor and ceiling effects in 132 participants seeking for treatment due to lower extremity dysfunction. Results: The Spanish version of the LEFS had high internal consistency (Cronbach's α = 0.989), test-retest reliability (ICC = 0.998, 95% CI: 0.996-0.999) and presented a high correlation with the SF-36 (36-Item Short-Form Health Survey) especially with the physical function and pain subscales. The construct validity showed a single factor that account for 84.95% of the variance. The standard error of measurement of the Spanish version of the LEFS was 0.88 scale points (95% CI) and the minimal detectable change was 2.18 scale points (95% CI). The sample, collected from five Spanish physical therapy centers, was divided in groups (acute, sub-acute and chronic subjects). Within group changes showed a significant improvement on the LEFS score (p