Health technologies for rare diseases: does conventional HTA still apply?

Abstract

As part of a health technology assessment, economic evaluation of health technologies for rare diseases poses specific challenges given that such technologies are rarely cost-effective. Therefore, conventional economic evaluation techniques appear to be less relevant to health technologies for rare diseases. However, the definition of health technology assessment points to multi-criteria decision analysis by stating that a health technology needs to be assessed against multiple criteria in order to pronounce a judgement about the value of the health technology. Thus, this editorial argues that a full health technology assessment which uses a multi-criteria decision analysis framework to evaluate the value of a technology can be applied to health technologies for rare diseases. Past experiences demonstrate that the specific characteristics of health technologies for rare diseases can fit in the conventional health technology assessment paradigm by means of multi-criteria decision analysis.

Keywords::

• health technology assessment
• health technology
• multi-criteria decision analysis
• rare diseases

A health technology assessment (HTA) can be defined as a form of policy research that employs a multidisciplinary process with a view to analyzing the medical, social, economic and ethical issues related to the use of a health technology [1]. At first sight, HTA therefore seems to be particularly suited to evaluate health technologies for rare diseases, which tend to have clinical, economic, social, equity and budgetary implications. As a result, many healthcare payers apply HTA to health technologies for rare diseases. For instance, the Canadian Agency for Drugs and Technologies in Health applies the same HTA-driven reimbursement review process to health technologies for common diseases and to technologies for rare diseases. Similarly, the Scottish Medicines Consortium uses the same HTA assessment process for all health technologies, although a higher cost per quality-adjusted life-year and more uncertainty may be accepted for health technologies for rare diseases [2]. However, the Scottish Medicines Consortium is currently revisiting their processes and may propose a new framework for assessing health technologies for rare diseases.

As part of an HTA, an economic evaluation assesses the value of health technology for rare diseases by considering its cost-effectiveness. The application of economic evaluation to health technologies for rare diseases poses specific challenges, given that such technologies are rarely cost-effective due to their often high price and limited effectiveness [3]. As a result, economic evaluation techniques are deemed to be less relevant to health technologies for rare diseases, particularly because the failure to cover such technologies that are not cost-effective often meets with political and social resistance [4]. If HTA cannot be applied to health technologies for rare diseases, what frameworks can be used to evaluate such technologies and provide the requisite evidence to decision makers in an era of evidence-based medicine?

Multi-criteria decision analysis can be such a framework [5,6]. In multi-criteria decision analysis, relevant decision-making criteria and their relative importance are identified by an expert panel. Techniques such as discrete choice experiments may serve to elicit the relative importance of criteria. Then the degree to which a health technology attains each criterion is assessed. The overall performance of a health technology is computed by aggregating the scores of the health technology on the different criteria. Finally, the finite budget is allocated to health technologies based on their ranking according to their scores [7]. In fact, multicriteria decision analysis provides a framework that is consistent with HTA, given that the definition of HTA points to multicriteria decision analysis by stating that a health technology needs to be assessed against multiple criteria in order to pronounce a judgment about the value of the health technology.

Several authors have advocated the application of multicriteria decision analysis to health technologies for rare diseases [8,9]. For instance, Hughes-Wilson et al. argued that standard HTA methods need to be tailored to consider the specificities of orphan drugs and that multicriteria decision analysis could serve as a tool to inform healthcare payer the coverage decisions of health technologies for rare diseases. Such a framework could enable healthcare payers to handle the different characteristics of health technologies for rare diseases and to take coverage decisions according to the differentiated assessment [8].

Is it possible to apply a multicriteria decision analysis framework to health technologies for rare diseases? The Office of Health Economics used this approach to provide a value framework for health technologies for rare diseases [9]. Workshop participants identified eight nonmonetary criteria (four about the disease and four about the health technology) and carried out a weighted assessment of two health technologies for rare diseases against these criteria. The authors concluded that multicriteria decision analysis provides a practical framework that can inform decision making and that the application of such a framework would enhance consistency and transparency in decision making.

A recent report discussed the (dis)advantages of applying multicriteria decision analysis to health technologies for rare diseases [10]. Multicriteria decision analysis benefits from its flexibility to consider a broader set of social values (which are particularly relevant to health technologies for rare diseases) rather than cost-effectiveness only, from the possibility to integrate multiple criteria and from its potential as a consistent priority setting framework. However, disadvantages of multicriteria decision analysis include difficulties to enroll a representative expert panel that generates societal preferences, lack of long-term sustainability in an era of cost containment, need to determine the perspective from which value is assessed and lack of practical experience with multicriteria decision analysis.

Is multicriteria decision analysis used by healthcare payers to evaluate health technologies for rare diseases in practice? In England, the Advisory Group for National Specialized Services (AGNSS) was the first healthcare payer in Europe to apply a multicriteria decision analysis framework to health technologies for ultra-rare diseases [11]. Its framework assesses 12 criteria, which are grouped into: health gain; societal value; reasonable cost; and best practice. The AGNSS framework benefits from the fact that a holistic view is taken (rather than that a single criterion dominates), a broader societal perspective is taken than the cost per quality-adjusted life-year, and flexibility is applied about the evidence base depending on the health technology and patients [12].

Since April 2013, the responsibilities of AGNSS have been taken over by the National Institute for Health and Care Excellence (NICE). In its document outlining the interim process and methods of the highly specialized technologies (i.e., technologies targeting less than 500 patients in England) program [13], NICE builds on the AGNSS framework, while arguing that the utilitarian approach underlying standard economic evaluation does not recognize the specific characteristics of health technologies for ultra-rare diseases. In essence, NICE applies a multicriteria decision analysis framework, taking account of the following criteria: nature of the condition, impact of the new technology, cost to the National Health Service and Personal Social Services, value for money, impact of the technology beyond direct health benefits and the impact of the technology on the delivery of the specialized service.

In conclusion, although conventional economic evaluation techniques appear to be less relevant to health technologies for rare diseases, a full HTA that uses a multicriteria decision analysis framework to evaluate the value of a technology can be applied to health technologies for rare diseases. Theoretical work by the Office of Health Economics has already identified criteria and their relative weights that can be used in a multicriteria decision analysis framework for health technologies for rare diseases. From a practical point of view, NICE is also looking to apply such a framework to value health technologies for ultra-rare diseases. These experiences demonstrate that the specific characteristics of health technologies for rare diseases can fit in the conventional HTA paradigm by means of multicriteria decision analysis.

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.