Challenges in the clinical and economic evaluation of medical devices: The case of transcatheter aortic valve implantation

Innovation in the Medical Device (MD) sector is developing at a rapid pace, thus enabling healthcare systems to deliver care where it was not possible. Therefore, it is important to assess the value of MDs so that policy-makers can make informed resource allocation decisions and set priorities. The clinical and economic evaluation of MDs poses greater challenges than the evaluation of drugs. First, it is more difficult to conduct randomised controlled trials of devices, because there is a ‘learning curve’ in their use. Also, the implementation of a new therapy involving a device can have wider economic implications for the organisation and financing of healthcare. The difficulties in obtaining clinical evidence on specific MDs may mean that there is a greater tendency to ‘generalise’ experience with similar devices. Finally, whereas the prices of drugs tend to be set until they become generic, the prices of MDs are more likely to change over time. The purpose of this article is to explore these issues further, using the case study of transcatheter aortic valve implantation (TAVI). TAVI is a promising alternative for patients at high risk for standard aortic valve replacement by open surgery or for patients deemed unsuitable for surgery. TAVI provides an excellent illustration of the complexities in evaluating MDs. It is clear that the procedures for the evaluation of drugs cannot simply be applied to devices. More discussion is required to identify arrangements that will not harm innovation, yet will lead to the development of new products that are safe, effective and good value for money.