Patient-Perceived Disability Following Transtibial Amputation and Prosthetic Limb Fitting

Abstract

ABSTRACT Introduction Patients’ perception of their disability following lower-limb amputation is currently measured using patient-reported outcomes (PROs) instruments. The validity is determined by comparing instruments designed to measure patient-perceived impact on amputation-specific health-related quality of life. The goal of this investigation was to compare patient-perceived disability from an outcomes instrument specific to individuals with amputation to a well-accepted outcomes instrument used to measure disability and response to treatment in generic musculoskeletal disease. Materials and Methods Twenty-one patients completed the Prosthesis Evaluation Questionnaire (PEQ) and the Short Musculoskeletal Functional Assessment (SMFA) at a minimum of 3 months following transtibial amputation while undergoing prosthetic limb fitting and gait training. A functional measure of their walking ability based on Medicare ambulatory function (Amputee Mobility Predictor [AMP]) was scored by a trained rehabilitation professional. Results The results of the outcomes scores provided initial evidence that the PEQ and SMFA assessments are correlated (i.e., provide some evidence of convergent validity). For every 100-point improvement in patients’ PEQ score, their SMFA Bother score declined by approximately 7 points (b = −6.94; P = 0.001) and Dysfunction score declined by approximately 7 points (b = −6.74; P < 0.001). Conversely, the SMFA and PEQ subscores were not associated with the AMP K-level (all P's > 0.05). Conclusions The findings suggested that the PEQ and SMFA PRO instruments are correlated in their ability to measure impact on health-related quality of life. Additionally, we found that PROs (PEQ and SMFA) did not predict physical ability as measured by the AMP K-level. The value of this investigation suggests that the easy-to-administer SMFA correlates well with the accepted PEQ, making testing both less cumbersome and time-consuming. Neither measure correlated with eventual ambulatory function. Rehabilitation following lower-limb amputation demands patient-specific goals. Available tools appear valuable in assisting the rehabilitation team in developing realistic objective tools for rehabilitation following lower-limb amputation. Clinical Relevance The simple-to-use SMFA appears to be comparable to the more cumbersome PEQ in assessing patient outcomes following transtibial amputations. Neither outcome instrument is correlated with functional task performance in this patient population.