LA: Lower Limb Functional Index: development and clinimetric properties. Phys Ther 2012

Background. Existing lower-limb region-specific patient-reported outcome mea-sures have clinimetric limitations, including limitations in psychometric characteris-tics (eg, lack of internal consistency, lack of responsiveness, measurement error) and the lack of reported practical and general characteristics. A new patient-reported outcome measure, the Lower Limb Functional Index (LLFI), was developed to address these limitations. Objective. The purpose of this study was to overcome recognized deficiencies in existing lower-limb, region-specific, patient-reported outcome measures through: (1) development of a new lower-extremity outcome scale (ie, the LLFI) and (2) eval-uation of the clinimetric properties of the LLFI using the Lower Extremity Functional Scale (LEFS) as a criterion measure. Design. This was a prospective observational study. Methods. The LLFI was developed in a 3-stage process of: (1) item generation, (2) item reduction with an expert panel, and (3) pilot field testing (n18) for reliability, responsiveness, and sample size requirements for a larger study. The mai