Lower Limb Prosthetics Outcome Measures Toolkit

Purpose

This toolkit is a recommendation for clinical use of outcome measures (OM) created to inform the practice of prosthetists providing prosthetic care for adults with lower-limb loss or lower-limb difference.

Introduction

Evidence-based clinical practice promotes consistency between practitioners, demonstrates service value, and elevates patient care. Use of OMs to objectively measure effectiveness of interventions and inform clinical decision-making is a tenet of evidence-based practice. Limited knowledge, resources, and time are among the major barriers to OM utilization in clinical practice. This document aims to address these barriers by recommending to prosthetists OMs that are most suitable for routine clinical care. Prosthetists are encouraged to administer a combination of these OMs during patient encounters with the goal of informing care as well as demonstrating intervention effectiveness and value. Administration of measures is suggested at initial evaluation, at or near prosthesis delivery, and at regular follow-up appointments (e.g., three months, six months, and one year). Administration of all recommended measures at every patient visit may not be feasible or appropriate; thoughtful use is encouraged.

Methods

This toolkit was developed by a working group within the Outcomes Research Committee of the American Academy of Orthotists and Prosthetists according to internal guidelines for development.¹ Members consulted content experts and reviewed secondary knowledge sources in lower-limb-loss research, ^2-5 including the 2018 Agency for Healthcare Research and Quality Comparative Effectiveness Review on Lower-Limb Prostheses.⁶ OMs considered for the toolkit were drawn from OMs that are routinely used in prosthetics practice, that members of the working group were familiar with, or that were described in the reviewed sources. OMs included in the toolkit were evaluated for their ability to measure select constructs of patient health, as defined by the International Classification of Functioning, Disability and Health (ICF, Table 3).

The working group identified and reviewed 27 OMs used clinically or in research among adults with lower-limb loss. Thirteen of these were patient-report measures assessing patient perception or experience, 13 were performance-based measures objectively assessing patient capacity under a given set of conditions, and one included aspects of both types.

To reduce this list to recommended in the toolkit, the working group considered the psychometric properties and clinical feasibility of the evaluated OMs. Specific OM characteristics considered included predictive validity, patient safety, cost, licensing requirements, time burden, space, portability, ease of administration, current utilization trends, and anticipated acceptability by clinicians. Due to the lack of consistency in psychometric evaluation in the literature, direct comparison between measures was not attempted. Overall psychometric quality of OMs was subjectively considered by the working group.

To maximize potential clinician adoption, a concise recommendation was the goal of the toolkit development. The working group was sensitive to each OM's potential for supporting intervention or reimbursement decisions and predicting or differentiating between Medicare Functional Classification Levels (MFCL) or K-levels. The working group also considered similar projects by different international groups.^7-9

The toolkit received input from an expert advisory panel and was approved by the Academy’s Research Council. It will be reviewed and updated in the future as relevant evidence and methods for OM selection emerge in lower-limb prosthetics.

_{Table 3. Lower Limb Prosthetics Outcome Measures Toolkit ICF Basis Set}

Toolkit OM Recommendations

The Recommended Patient-Report Outcome Measures for the prosthetic treatment of adult individuals with lower-limb loss or difference include:

• EQ-5D-5L^™ (health-related quality of life)
• Prosthetic Limb Users Survey of Mobility (PLUS-M^™)
• Socket Comfort Score (SCS)

The Recommended Performance-Based Outcome Measures for the prosthetic treatment of adult individuals with lower-limb loss or difference include:

• 10-meter Walk Test (10mWT)
• Amputee Mobility Predictor^© (AMPPRO, AMPnoPRO)
• Timed Up and Go (TUG)

Practitioners should consider a combination of patient-report and performance-based mobility measures in evaluation of mobility, since patient perception may differ from functional capacity.

Further, functional capacity on a given day may vary based on patient and environmental factors including socket comfort and fit, limb pain, fatigue, assistive-device use, and transient impairments. Consequently, when OM data changes, prosthetists should consider other relevant factors to explain this change. For example, a reduction in patient-reported mobility measured with the Prosthetic Limb Users Survey of Mobility (PLUS-M^™) or observed mobility measured with the Timed Up and Go (TUG) may be accompanied by a reduction in Socket Comfort Score (SCS). This reduction in socket comfort could explain the reduction in actual or perceived mobility.