Preliminary Evaluation of the Clinimetrics of a Modified Lower Extremity Functional Scale in Older Adults After Total Knee Arthroplasty

Abstract

OBJECTIVE: To conduct a preliminary evaluation of the clinimetrics of a modified version of the Lower Extremity Functional Scale (LEFS) administered to older adults undergoing rehabilitation after total knee arthroplasty. DESIGN: Prospective pretest-posttest pilot study. METHODS: Patients who had undergone knee arthroplasty and entered rehabilitation at an outpatient physical therapy clinic completed the modified LEFS for osteoarthritis (LEFS-OA) at evaluation and at discharge. A dependent-samples t test assessed changes in scores between initial evaluation and discharge. The effect size and minimal clinically important difference (MCID) were calculated. RESULTS: Sixty patients (36 females, 24 males; mean age [standard deviation], 70.21 [9.23] years) participated. Cronbach’s α was 0.89 at evaluation and 0.93 at discharge. The mean (standard deviation) score of the LEFS-OA was 34.27 (12.60) at evaluation and 47.10 (8.61) at discharge ( P<.001). The effect size for change from pretest to posttest was 1.13. The standardized response mean was 1.25. The MCID was 6.30, and 70.0% (42) of patients exceeded the MCID after an average of 12 visits. CONCLUSION: Preliminary analysis suggested that the LEFS-OA had promising psychometric properties, and further investigation to include criterion validation of this reduced version of the LEFS, after further development, may be justified. JOSPT Open 2024;2(3):240-245. Epub 3 April 2024. doi:10.2519/josptopen.2024.0919