In the following, we will propose directions for the evaluation of prosthetic care as one requirement to solve the broader ethical problem of just resource allocation in health care systems.
5.1. HTA—Assessment of Costs and Benefits and the QALY Concept
General process and content criteria for prioritisation as defined by the German ethics committee on medicine [4
] are a first prerequisite to make reimbursement more just. Though it is contested how and if at all, one can optimise the benefit across the whole population in a just manner, the effectiveness of prosthetics should play some role for distribution of resources. After all, it is the primary goal of health care to improve quality of life of people, and non-effective treatments will drain resources from other areas of health care where people may benefit. The next and probably more laborious step towards just reimbursement would thus be to find methods for effectiveness evaluation of specific technologies. Biddiss et al. see the evidence-based evaluation of prosthetic practices and outcomes as a prerequisite for reimbursement policy change [1
Deciding about the reimbursement of prosthetics based on benefits and costs is in fact one (simple) way of interpreting the criterion of being based on evidence, which the ZEKO defined. This refers to the term “evidence-based medicine” (EBM), which stands for the principle to use the best evidence at hand, ideally the statistically significant outcome of prospective randomized controlled trials, and summarize it according to a certain standard systematically in order to inform approval decisions by regulatory bodies. An evidence-based evaluation has been suggested to be highly beneficial for prosthetic care specifically, both to empirically justify prescription of high cost prostheses [67
], but also to improve quality and raise efficiency [41
]. In Germany, evidence-basedness of reimbursement means that only such medical treatments are reimbursed which have a benefit going beyond alternative treatments [2
For pharmaceuticals, the benefit gain of the new treatment in comparison to existing treatments, and their respective prices, are used to negotiate the price of a new treatment between manufacturer and GKV [2
]. This procedure has the advantage that nothing is being withheld from patients based on costs, but still some form of limiting the rising costs for pharmaceuticals is achieved.
This limit is however quite arbitrary as the “starting price” for a specific indication is taken mostly as pre-given and can basically be determined by the manufacturer who puts the first treatment for a certain indication on the market [2
] (p. 45). An assessment of benefit and costs of prosthetic technology could be not only a quality and cost control mechanism within a specific health care sector, but also a first step towards a comparability of treatments across sectors, like cancer and prosthetic care.
In the UK, there is now a regulation in place which sets a limit of Euros a Quality adjusted life year (QALY, a measure of gains in both quality and length of life) may cost in order to be reimbursable. Above a certain limit (around 25,000 £/QALY), reimbursement is not excluded but demands specific justification [50
] (p. 23). Though methodologically difficult, there are studies asking the general public for their willingness to pay for one QALY, with the aim of democratically legitimising such a number [68
]. There are only few attempts to evaluate cost-effectiveness of prostheses up to now. Two studies evaluating the same prosthesis came to very different results of 3000 vs. 35,000 Euros/QALY [69
], which shows that it is still a methodological challenge to measure QALYs, besides ethical objections [66
] (pp. 64–65). But at least all three studies found Euro/QALY amounts below the assumed Euro/QALY limit of the UK, a result that might suffice as a legitimisation for reimbursement.
Whether a health care system uses an approach with QALYs like in the UK or negotiates prices based on additional benefits of a treatment like in Germany, it is important to have an evidence base in the form of reliable studies. Without scientific evidence, the uptake and diffusion of health technologies is likely to be influenced by a range of social, financial and institutional factors, resulting in suboptimal health outcomes and inefficient use of resources [50
]. For prostheses, the evidence base is rather scarce (for microprocessor controlled knees one can at least find several studies, see [69
]), and only a few HTA studies can be found for upper limb prostheses [72
]. This may be a critical point explaining insurance providers’ unwillingness to provide more expensive prosthetics. It also makes it difficult to change regulations in a way incorporating the evidence-basedness criterion of the ZEKO and thus make it more difficult for insurance providers to proceed with implicit rationing. One more option would of course be to give insured access to prosthetics without any interference option by insurance providers. The past has shown, however, that in a profit driven medical sector, this is in general not the best option. Without quality control mechanisms like a systematic, manufacturer independent benefit evaluation in place, it may result in high prices for medical products with low quality, thus worsening the financial problems of the health care system and not necessarily fostering the development of good products and patient care.
Also, while an inclusion of social aspects as discussed above might alleviate the health care budget problem by making prosthetic care supposedly more efficient, this has to be assessed in some objective way, e.g., by HTA, as well. We will consider prosthetic care evaluation from a broader, multidisciplinary perspective rather than a narrow perspective focusing on (objectively measurable) physiological parameters and direct costs of the prosthetic technology. This is why we come back to our findings from the social science literature here as well.
Overall, we try to bring socio-economic/HTA, ethical and social perspectives on limb prosthetics together in a so far unique way. Furthermore, we give some policy recommendations with regard to starting the process of discussing the reimbursement process and regulation and possible changes.
5.2. Hurdles for HTA-Based Reimbursement
There are three intertwined hurdles for developing HTA-based reimbursement criteria for prosthetics. One is that guidelines or standards on evidence-based evaluation of prosthetic care (and medical devices generally) are lacking so far [10
] (p. 10). HTA agencies state that the available studies they had to base their assessment on were generally small and methodologically weak [69
]. The available number of HTAs is very low. Also, the studies which the HTAs are based on were mostly sponsored by manufacturers and patients were often fit and healthy adults, which means a low generalisability of results [69
]. Outcome measures are heterogeneous and thus difficult to summarise or compare between studies [71
], and only some studies assess quality of life, but most of them rely on functional outcomes like speed, balance, gait biomechanics, and energy expenditure [69
One reason for the scarcity of clinical studies and HTAs is the legal framework for medical devices in Germany and the EU. Medical products of low risk (class I and IIa), there is no obligation for manufacturers to make a benefit evaluation at all [10
]. The sole requirement to gain market access is the CE mark which is basically a certificate for compliancy with safety standards [10
] (p. 58). The Federal Social Court (BSG—Bundessozialgericht) decided in 2015 that if a medical aid (prostheses are also classified as medical aids, which is crucial for reimbursement regulation) is innovative, insurances are not allowed to reimburse it without further investigations on benefit [74
]. For new prostheses that are not seen as “innovative” by the G-BA (Gemeinsamer Bundesausschuss), there is no incentive for producers to conduct more studies on effectiveness than necessary for CE mark purposes. Rather, this would be a financial burden and a risk in case of negative study results. Thus, to encourage the conduct of studies according to standards of evidence-based medicine (EBM), a more demanding legal framework is needed. At the same time, care has to be taken that small and medium-sized companies (SME) are not overburdened with complex, costly and time-consuming requirements [10
] (p. 10). Currently, the framework in Germany is insufficient in this regard, and policymakers can produce innovation impulses by helping to develop evaluation processes [10
] (p. 11). The question of who has to finance studies has also to be solved [75
The third issue is that there are methodological difficulties with the evaluation of medical devices in general, as they are characterised by complexity, incremental innovation and dependency of effectiveness on the care provider (as discussed in depth in [73
]). Medical device manufacturer associations in Germany are calling for the development of scientific guidelines for a transparent benefit evaluation of new medical products [64
]. Otherwise, uncertainty and complexity of the regulatory framework may hinder the realisation of new ideas in medical technology development in Germany [10
] (p. 11).
Methods and regulation of benefit evaluation should ideally be innovation-friendly, user-centred, mirroring real-life care settings [76
] and satisfying the demands of insurances who wish to legitimize their decisions based on good evidence [75
]. There is a huge breadth of possibilities concerning the evaluation of prosthetics. One has to choose the point in time (before or after market access, right after fitting or after a time period for letting the user adapt), number of users and prosthetic models studied in every user, mode of study (registry or clinical study, case studies) and most importantly, measurement instruments/outcomes.
The ZEKO gives only very general hints with regard to evaluation of prosthetic technology: Benefit evaluation of medical treatments should be both evidence-based and patient-oriented, and evidence has to be gained systematically [4
]. A general conclusion from that is that it is important to include quality of life as a criterion for reimbursement and not only a functional evaluation (as, for example, asking whether the user is able to walk a certain distance with the prosthesis in a certain manner).
5.3. The Role of Social Factors for the Assessment of Prosthetics
Social acceptance factors interact with technical aspects of the prosthesis, as shown in the first part of this paper. Thus, it is not reasonable to measure or predict benefit based solely on surrogate parameters like functionality at a certain time point, only because they are easier to measure and quantifiable. Other non-quantifiable values like patient preferences, acceptability, equity concerns and indirect benefits and costs should be accounted for in HTA assessments if they are used as a basis for reimbursement decisions [50
In addition, the context of evaluation can be crucial for the result. Opinions and experiences of health care professionals and individual users are needed to understand the real-world benefit of a technology [50
]. For example, when a user has not been involved in choosing the prosthesis, the evaluation result will be misleading regarding the potential of the technology (it would have in an optimal care and social setting). Thus, social acceptance research is important to consider when thinking about how, when, in which setting, and by whom prostheses should be evaluated to get valid results that are transferable to future users. However, a conclusion might also be that prosthetic care success is to such an extent individual and the context so decisive for the benefit of a prosthetic technology that no prediction regarding an individual could or should be drawn from the general population of users. If this is true, it might not be an unavoidable obstacle for prosthesis evaluation, as wearing a prosthesis has no such acute or irreversible side effects as pharmaceuticals and implants.
Though social aspects of prosthesis acceptance are crucial, new technological developments also have to be taken into account when thinking about policies of prosthetic evaluation and reimbursement. Individual designs, e.g., with 3D printing of prosthetics (or Lego Limbs) can boost acceptance and are assumed to contribute to a positive self-image, particularly in children. The personalization/individualization of medical treatments which is discussed for medical substances as a challenge for effectiveness testing methods [10
] (p. 10), and there might be critical voices not accepting this kind of aesthetic demands as medically strictly necessary. Further research is thus needed on this specific aspect of aesthetics and related regulatory questions around individualized medical products, both regarding safety [78
] and reimbursement. Reimbursement regulation for individualised medical products is generally complex and intransparent in Germany [10
] (p. 11).
One approach would be a systematic evaluation with questionnaires conducted directly by the care providers (doctors or prosthetists) and collected in registries. With regard to a suitable method, a prosthesis evaluation questionnaire (PEQ) is available to measure quality of life of people with limb loss and quantify the benefit of using a prosthesis [79
]. It was used to assess one microprocessor-controlled knee in a US study. However, in Germany, there are no medical registries for people with limb loss and the authors could not find published studies using the PEQ. Tools like PEQ are needed and should be validated further, as well as anchored in guidelines and teaching in prosthetics.
An individual evaluation per case by the care providers in this manner could open up possibilities for testing a new and diverse set of prostheses for every user in order to make the best individual choice and at the same time produce data that could be aggregated to generate more general conclusions about benefits of specific prosthesis models for specific user groups. Testing the benefit of prostheses under real-world conditions improves the reliability of the evaluation. Another advantage is the fact that evaluation after market access is generally innovation friendlier. Products can be sold while in the testing phase, users can get access to potentially beneficial technology, but at the same time it is guaranteed that products without sufficient benefit are deselected based on the collected data. Of course, safety-testing is still needed before market access. A drawback of this approach is that a full evaluation for every user would need extra time resources on behalf of the prosthetic technician and the user him/herself.
5.4. Early Stakeholder Dialogue and Implementation of Reimbursement Recommendations
We described a possible approach for evaluation and made reference to a validated method from the literature here. However, this is only a suggestion, and pros and cons for this and other approaches as well as combinations thereof (like randomized controlled trial combined with registry data [77
]) have to be discussed by experts and stakeholders specifically for prosthetic care in our view. It has been argued that HTA (of effectiveness/benefit) and regulatory evaluation (of safety) should be aligned for medical products [75
]. The German Academia of Engineering Sciences (ACATECH) recommends a collaboration of representatives of clinical medicine, industry and research, as well as regulatory agencies to develop suitable guidelines for effectiveness/benefit evaluation of individualized medical products [10
] (p. 11), and patient feedback on the quality criteria used [10
] (p. 64). For the case of prosthetics, we would also suggest incorporating prosthetists besides users.
An important issue to think about would also be how to implement more standardised and evidence-based reimbursement criteria once they are developed and consented on. The current situation shows that there is a lot of uncertainty about the claims of prosthetic users. In the future, this uncertainty should be avoided by clear guidelines on reimbursement, which are open and understandable for professionals and insurance employees involved in the process.
A possibility might be to use existing practice guidelines as a platform. Insurances are not obliged to reimburse practices which are recommended in guidelines. However, if resulting in better and more efficient care, insurances should in their own interest support the implementation of (best practice) guidelines. The NHS (National Health Service of England) proposes that with a standardised practice related outcome evaluation (of orthotics) one could develop practical guidelines that could improve quality of care and save money [70
]. The impact of prosthetic guideline implementation has to be evaluated in order to prove such claims [47
]. Reimbursement decision (bodies) (in Germany G-BA and GKV), practical guideline developers (clinicians and prosthetists) and HTA assessment bodies are however separated [50
] (p. 5). A closer collaboration might help in aligning best practice and prescription guidelines with reimbursement decisions of insurances.