ECONOMIC EVALUATIONS OF INTERVENTIONS FOR TRANSTIBIAL AMPUTEES: A SCOPING REVIEW OF COMPARATIVE STUDIES

Insights into the spectrum of transtibial prosthetic socket design from expert clinicians and their digital records

Background

Transtibial prosthetic sockets are often grouped into patella tendon bearing (PTB) or total surface bearing (TSB) designs, but many variations in rectifications are used to apply these principles to an individual's personalised socket. Prosthetists currently have little objective evidence to assist them as they make design choices.

Aims

To compare rectifications made by experienced prosthetists across a range of patient demographics and limb shapes to improve understanding of socket design strategies.

Methodology

163 residual limb surface scans and corresponding CAD/CAM sockets were analysed for 134 randomly selected individuals in a UK prosthetics service. This included 142 PTB and 21 TSB designs. The limb and socket scans were compared to determine the location and size of rectifications. Rectifications were compiled for PTB and TSB designs, and associations between different rectification sizes were assessed using a variety of methods including linear regression, kernel density estimation (KDE) and a Naïve Bayes (NB) classification.

Results

Differences in design features were apparent between PTB and TSB sockets, notably for paratibial carves, gross volume reduction and distal end elongation. However, socket designs varied across a spectrum, with most showing a hybrid of the PTB and TSB principles. Pairwise correlations were observed between the size of some rectifications (e.g., paratibial carves; fibular head build and gross volume reduction). Conversely, the patellar tendon carve depth was not associated significantly with any other rectification, indicating its relative design insensitivity. The Naïve Bayes classifier produced design patterns consistent with expert clinician practice. For example, subtle local rectifications were associated with a large volume reduction (i.e., a TSB-like design), whereas more substantial local rectifications (i.e., a PTB-like design) were associated with a low volume reduction.

Clinical implications

This study demonstrates how we might learn from design records to support education and enhance evidence-based socket design. The method could be used to predict design features for newly presenting patients, based on categorisations of their limb shape and other demographics, implemented alongside expert clinical judgement as smart CAD/CAM design templates.

Out-of-pocket costs and affordability of upper limb prostheses

BACKGROUND

Given the funding policies in the Department of Veterans Affairs, the affordability of prostheses may be less of a concern among Veterans as compared to civilians.

OBJECTIVES

Compare rates of out-of-pocket prosthesis-related payments for Veterans and non-Veterans with upper limb amputation (ULA), develop and validate a measure of prosthesis affordability, and evaluate the impact of affordability on prosthesis nonuse.

STUDY DESIGN

Telephone survey of 727 persons with ULA; 76% Veterans and 24% non-Veterans.

METHODS

Odds of paying out-of-pocket costs for Veterans compared with non-Veterans were computed using logistic regression. Cognitive and pilot testing resulted in a new scale, evaluated using confirmatory factor and Rasch analysis. Proportions of respondents who cited affordability as a reason for never using or abandoning a prosthesis were calculated.

RESULTS

Twenty percent of those who ever used a prosthesis paid out-of-pocket costs. Veterans had 0.20 odds (95% confidence interval, 0.14-0.30) of paying out-of-pocket costs compared with non-Veterans. Confirmatory factor analysis supported unidimensionality of the 4-item Prosthesis Affordability scale. Rasch person reliability was 0.78. Cronbach alpha was 0.87. Overall, 14% of prosthesis never-users said affordability was a reason for nonuse; 9.6% and 16.5% of former prosthesis users said affordability of repairs or replacement, respectively, was a reason for abandonment.

CONCLUSIONS

Out-of-pocket prosthesis costs were paid by 20% of those sample, with Veterans less likely to incur costs. The Prosthesis Affordability scale developed in this study was reliable and valid for persons with ULA. Prosthesis affordability was a common reason for never using or abandoning prostheses.

Digital healthcare technologies: Modern tools to transform prosthetic care

INTRODUCTION

Digital healthcare technologies are transforming the face of prosthetic care. Millions of people with limb loss around the world do not have access to any form of rehabilitative healthcare. However, digital technologies provide a promising solution to augment the range and efficiency of prosthetists.

AREAS COVERED

The goal of this review is to introduce the digital technologies that have the potential to change clinical methods in prosthetic healthcare. Our target audience are researchers who are unfamiliar with the field of prostheses in general, especially with the newest technological developments. This review addresses technologies for: scanning of amputated limbs, limb-to-socket rectification, additive manufacturing of prosthetic sockets, and quantifying patient response to wearing sockets. This review does not address biomechatronic prostheses or biomechanical design practices.

EXPERT OPINION

Digital technologies will enable affordable prostheses to be built on a scale larger than with today's clinical practices. Large technological gaps need to be overcome to enable the mass production and distribution of prostheses digitally. However, recent advances in computational methods and CAD/CAM technologies are bridging this gap faster than ever before. We foresee that these technologies will return mobility and economic opportunity to amputees on a global scale in the near future.

A Preliminary Cost-Utility Analysis of the Prosthetic Care Innovations: Basic Framework

A preliminary cost-utility analysis (CUA) of prosthetic care innovations can provide timely information during the early stage of product development and clinical usage. Concepts of preliminary CUAs are emerging. However, several obstacles must be overcome before these analyses are performed routinely. Disparities of methods and high uncertainty make the outcomes of usual preliminary CUAs challenging to interpret, appraise and share. These shortcomings create opportunities for a basic framework of preliminary CUAs. First, I introduced a basic framework of a preliminary CUA built around a series of constructs and hands-on recommendations. Then, I appraised this framework considering the strengths and weaknesses, barriers and facilitators, and return on investment. The design of the basic framework was determined through the review of health economic and prosthetic-specific literature. A preliminary CUA comparing the costs and utilities between usual intervention and an innovation could be achieved through a 15-step iterative process focusing on feasibility, constructs, analysis, and interpretation of outcomes. This CUA provides sufficient evidence to identify knowledge gaps and improvement areas, educate about the design of subsequent full CUAs, and obtain fast-track approval from governing bodies. Like previous CUAs, the main limitations were inherent to the constructs (e.g., narrow perspective, plausible scenarios, mid-term time horizon, substantial assumptions, data mismatch, high uncertainty). Key facilitators potentially transferable across preliminary CUAs of prosthetic care innovations included choosing abided constructs, capitalizing on prior schedules of expenses, and benchmarking baseline or incremental utilities. This new approach with preliminary CUA can simplify the selection of methods, standardize outcomes, ease comparisons between innovations, and streamline pathways for adoption. Further collegial efforts toward validating standard preliminary CUAs will facilitate access to economic prosthetic care innovations, improving the lives of individuals suffering from limb loss worldwide.

Trends and Opportunities in Health Economic Evaluations of Prosthetic Care Innovations

Overcoming obstacles to prosthetic fittings requires frequent tryouts of sockets and components. Repetitions of interventions are upsetting for users and place substantial economic burden on healthcare systems. Encouraging prosthetic care innovations capable of alleviating clinical and financial shortcomings of socket-based solutions is essential. Nonetheless, evidence of socio-economic benefits of an innovation are required to facilitate access to markets. Unfortunately, complex decisions must be made when allocating resources toward the most relevant health economic evaluation (HEE) at a given stage of development of an innovation. This paper first, aimed to show the importance and challenges of HEEs of intervention facilitating prosthetic fittings. Next, the main trends in HEEs at various phases of product development and clinical acceptance of prosthetic care innovations were outlined. Then, opportunities for a basic framework of a preliminary cost-utility analysis (CUA) during the mid-stage of development of prosthetic care innovations were highlighted. To do this, fundamental and applied health economic literature and prosthetic-specific publications were reviewed to extract and analyse the trends in HEEs of new medical and prosthetic technologies, respectively. The findings show there is consensus around the weaknesses of full CUAs (e.g., lack of timeliness, resource-intensive) and strengths of preliminary CUAs (e.g., identify evidence gaps, educate design of full CUA, fast-track approval). However, several obstacles must be overcome before preliminary CUA of prosthetic care innovations will be routinely carried out. Disparities of methods and constructs of usual preliminary CUA are barriers that could be alleviated by a more standardized framework. The paper concludes by identifying that there are opportunities for the development of a basic framework of preliminary CUA of prosthetic care innovations. Ultimately, the collaborative design of a framework could simplify selection of the methods, standardise outcomes, ease comparisons between innovations and streamline pathways for adoption. This might facilitate access to economical solutions that could improve the life of individuals suffering from limb loss.

The Value of Health Economics and Outcomes Research in Prosthetics and Orthotics

The demand has increased for evidence regarding the effectiveness and value of prosthetic and orthotic rehabilitation interventions. Clinicians and managers are under pressure to provide treatment recommendations and demonstrate effectiveness through outcomes. It is often assumed that rehabilitation interventions, including the provision of custom-made and custom-fit orthotic and prosthetic devices, are beneficial to patients. Assessing the value of orthotic and prosthetic services has become more critical to continue to ensure equitable access to needed services. Health economics and outcomes research methods serve as tools to gauge the value of prosthetic and orthotic rehabilitation interventions. The purpose of this article is to provide an overview of the current need of health economics and outcomes research in orthotics and prosthetics, to introduce common economic methods that assist to generate real-world evidence, and to discusses the potential value of economic methods for clinicians and clinical practice.

A systematic review of health economic evaluations in orthotics and prosthetics: Part 1 - prosthetics

BACKGROUND

The extent to which current prosthetic health economic evaluations inform healthcare policy and investment decisions is unclear. To further the knowledge in this area, existing evidence gaps and method design issues must be identified, thereby informing the design of future research.

OBJECTIVES

The aim of this systematic review was to identify evidence gaps, critical method design and reporting issues and determine the extent to which the literature informs a wide range of policy and investment decisions.

STUDY DESIGN

Systematic review.

METHODS

A range of databases were searched using intervention- and health economic evaluation-related terms. Issues with methodological design and reporting were evaluated using the Consolidated Health Economic Checklist - Extended and the Checklist for Health Economic Evaluation Reporting Standards.

RESULTS

The existing health economic evaluation literature was narrowly focused on informing within-participant component decisions. There were common method design (e.g. time horizon too short) and reporting issues (e.g. competing intervention descriptions) that limit the extent to which this literature can inform policy and investment decisions.

CONCLUSION

There are opportunities to conduct a wider variety of health economic evaluations to support within- and across-sector policy and investment decisions. Changes to aspects of the method design and reporting are encouraged for future research in order to improve the rigour of the health economic evaluation evidence.

CLINICAL RELEVANCE

This systematic review will inform the clinical focus and method design of future prosthetic health economic evaluations. It will also guide readers and policy-makers in their interpretation of the current literature and their understanding of the extent to which the current literature can be used to inform policy and investment decisions.

Lower limb prosthetic interfaces: Clinical and technological advancement and potential future direction

The human-prosthesis interface is one of the most complicated challenges facing the field of prosthetics, despite substantive investments in research and development by researchers and clinicians around the world. The journal of the International Society for Prosthetics and Orthotics, Prosthetics and Orthotics International, has contributed substantively to the growing body of knowledge on this topic. In celebrating the 50th anniversary of the International Society for Prosthetics and Orthotics, this narrative review aims to explore how human-prosthesis interfaces have changed over the last five decades; how research has contributed to an understanding of interface mechanics; how clinical practice has been informed as a result; and what might be potential future directions. Studies reporting on comparison, design, manufacturing and evaluation of lower limb prosthetic sockets, and osseointegration were considered. This review demonstrates that, over the last 50 years, clinical research has improved our understanding of socket designs and their effects; however, high-quality research is still needed. In particular, there have been advances in the development of volume and thermal control mechanisms with a few designs having the potential for clinical application. Similarly, advances in sensing technology, soft tissue quantification techniques, computing technology, and additive manufacturing are moving towards enabling automated, data-driven manufacturing of sockets. In people who are unable to use a prosthetic socket, osseointegration provides a functional solution not available 50 years ago. Furthermore, osseointegration has the potential to facilitate neuromuscular integration. Despite these advances, further improvement in mechanical features of implants, and infection control and prevention are needed.

The Role of Earlier Receipt of a Lower Limb Prosthesis on Emergency Department Utilization

Introduction

Adverse events after a lower limb amputation (LLA) can negatively affect the rehabilitation process and may lead to emergency department (ED) visits. Earlier receipt of a prosthesis, as compared to delayed or not receiving a prosthesis, may decrease or moderate the risk of increased ED utilization. In addition, adverse events (ie, fall‐related injury [FRI]) may be associated with increased health care utilization as measured by ED use. The implication of the timing of prosthesis provision after amputation and reduced ED use is not well established. Obtaining data about ED utilization early post‐LLA could assist the rehabilitation team in ensuring timely and appropriate access to improve outcomes.

Objective

To determine the role that timing of prosthesis receipt has in ED utilization and the association of fall/FRI with health care utilization.

Design

Retrospective observational cohort using commercial claims data. A logistic regression model was used to assess factors that influence ED utilization post‐LLA.

Setting

Watson/Truven administrative database 2014 to 2016.

Participants

The study sample consisted of 510 adults age 18 to 64 years with continuous enrollment for 3 years.

Interventions

Independent variables included age, sex, diabetes status, amputation level, fall diagnosis, and prosthesis receipt. Fall was defined as presence of a diagnosis code in any outpatient procedure after the amputation date.

Main Outcome Measure

ED use after amputation was defined as the presence of procedure codes that billed for ED services (99281 to 99285).

Results

Individuals who receive a prosthesis early, within 0 to 3 months, post‐LLA were 48% (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.28 to 0.97) less likely to use the ED compared to those who did not receive a prosthesis. Individuals who experienced a fall/FRI had 2.8 (OR 2.86, 95% CI 1.23 to 6.66) times the odds of ED utilization.

Conclusion

Receipt of a prosthesis reduces the risk of ED use. The current study underscores the value of prostheses during the rehabilitation process after LLA.

Effects of exercise on the physical fitness and functionality of people with amputations: Systematic review and meta-analysis

STUDY DESIGN

systematic review and meta-analysis.

BACKGROUND

Despite existing scientific evidence alluding to the positive effects of physical exercise on people with amputations, there is a lack of consistency between the results of past studies.

OBJECTIVE

To identify if people with amputations taking part in an exercise training programme can benefit from improvements in their health status as measured by changes in their physiological fitness and functionality levels.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) were performed after searching within several databases up to October 2019.

RESULTS

Ten RCTs with satisfactory methodological quality were found. Five RCTs were pooled in the meta-analysis. Exercise programmes with a combination of activities were most commonly delivered. Exercise had positive effects on aerobic and muscular fitness parameters. Findings from the meta-analysis indicated that exercise improved distance walked but did not have a significant impact on functional mobility or self-reported functional capacity.

CONCLUSION

Combined exercise of muscular endurance and functional physical exercise appear to have greater positive effects on cardiorespiratory fitness, muscular fitness and functionality levels in adult prosthesis users with unilateral lower limb amputation. Future studies should include different profiles of patients with amputations that are poorly represented in the current scientific literature.

A Pilot Study Testing a Novel 3D Printed Amphibious Lower Limb Prosthesis in a Recreational Pool Setting

Introduction

Adults with limb amputation and other physical disabilities are less likely to participate in physical activity than adults in the general population and have elevated risk of heart disease and stroke. Swimming is a physical activity often recommended for persons with limb amputation. However, a standard economical swim prosthesis that facilitates easy transition from land to water does not exist.

Objective

The objectives were (1) to measure ease of first‐time use and likability of a novel U.S. Food and Drug Administration (FDA)–cleared 510(k) three‐dimensional (3D) printed device, the “FIN,” in a recreational pool; and (2) to determine differences in time to complete basic swim tasks using the novel 3D printed amphibious lower limb prosthesis or a standard Swim Ankle prosthesis. Our hypotheses were the following: (1) that the novel 3D printed amphibious lower limb prosthesis would be easy and likeable upon first use; and (2) that basic swim tasks would take comparable time to complete with either device.

Setting

Academic medical center and community pool in New York.

Participants

Participants were (N = 10) English‐speaking adults with a transtibial amputation who self‐identified to swim comfortably in a recreational setting.

Interventions

Participants completed tasks typical of recreational swimming while wearing the novel 3D printed amphibious lower limb prosthesis or a Swim Ankle.

Main Outcome Measurements

Participants performed a series of recreational swim tasks at self‐selected speeds: entering/exiting pool, walking, swimming, and treading water, and completed a survey to assess the primary outcomes: likability, ease of use, and adverse events (feasibility).

Results

Participants found the novel 3D printed amphibious lower limb prosthesis more likable compared to the Swim Ankle and easy to use. Time to exit the pool was significantly reduced with the novel 3D printed amphibious lower limb prosthesis, while time to complete a 25‐m lap was comparable. Participants did not show significant changes in vital signs when using either prosthesis.

Conclusions

The novel 3D printed amphibious lower limb prosthesis was likable and easy to use upon first use. This study supports conducting a larger clinical trial to determine if the data are broadly reproducible.

Economic value of orthotic and prosthetic services among medicare beneficiaries: a claims-based retrospective cohort study, 2011-2014

Background

There are few studies of the economic value of orthotic and prosthetic services. A prior cohort study of orthotic and prosthetic Medicare beneficiaries based on Medicare Parts A and B claims from 2007 to 2010 concluded that patients who received timely orthotic or prosthetic care had comparable or lower total health care costs than a comparison group of untreated patients. This follow-up study reports on a parallel analysis based on Medicare claims from 2011 to 2014 and includes Part D in addition to Parts A and B services and expenditures. Its purpose is to validate earlier findings on the extent to which Medicare patients who received select orthotic and prosthetic services had less health care utilization, lower Medicare payments, and potentially fewer negative outcomes compared to matched patients not receiving these services.

Methods

This is a retrospective cohort analysis of 78,707 matched pairs of Medicare beneficiaries with clinical need for orthotic and prosthetic services (N = 157,414) using 2011–2014 Medicare claims data. It uses propensity score matching techniques to control for observable selection bias. Economically, a cost-consequence evaluation over a four-year time horizon was performed.

Results

Patients who received lower extremity orthotics had 18-month episode costs that were $1939 lower than comparable patients who did not receive orthotic treatment ($22,734 vs $24,673). Patients who received spinal orthotic treatment had 18-month episode costs that were $2094 lower than comparable non-treated patients ($23,560 vs $25,655). Study group beneficiaries receiving both types of orthotics had significantly lower Part D spending than those not receiving treatment (p < 0.05). Patients who received lower extremity prostheses had comparable 15-month episode payments to matched beneficiaries not receiving prostheses ($68,877 vs $68,893) despite the relatively high cost of the prosthesis.

Conclusions

These results were consistent with those found in the prior study and suggest that orthotic and prosthetic services provide value to the Medicare program and to the patient.

The role of exercise testing in predicting successful ambulation with a lower extremity prosthesis: a systematic literature review and clinical practice guideline

BACKGROUND

Growing discontent with the k-level system for functional classification of patients with limb loss and movement of healthcare toward evidence-based practice has resulted in the need for alternative forms of functional classification and development of clinical practice guidelines to improve access to quality prosthetic interventions. The purpose of this project was to develop and present a clinical practice recommendation for exercise testing in prosthetic patient care based on the results and synthesis of a systematic literature review.

METHODS

Database searches of PubMed, Google Scholar, Web of Science, and Cochrane were conducted and articles reviewed. Of the potential 1386 articles 10 met the criteria for inclusion. These articles were assessed using the critical appraisal tool of the United Kingdom National Service Framework for Long-Term Conditions. Of the 10 included articles eight were of high, one of medium, and one of low, quality. Data from these articles were synthesized into 6 empirical evidence statements, all qualifying for research grade A. These statements were used to develop the proposed clinical practice guideline.

RESULTS

While the results of this systematic review were not able to support the direct connection between cardiorespiratory performance and K-levels, the literature did support the ability of exercise testing results to predict successful prosthetic ambulation in some demographics. Both continuous maximum-intensity single lower extremity ergometer propelled by a sound limb and intermittent submaximal upper extremity ergometer protocols were found to be viable evaluation tools of cardiorespiratory fitness and function in the target population.

CONCLUSION

The ability to sustain an exercise intensity of ≥50% of a predicted VO2max value in single leg cycle ergometry testing and achievement of a sustained workload of 30 W in upper extremity ergometry testing were found to be the strongest correlates to successful ambulation with a prosthesis. VO2 values were found to increase in amputee subjects following a 6-week exercise program. These synthesized results of the systematic literature review regarding exercise testing in patients with loss of a lower extremity were used to develop and a present a clinical treatment pathway.