In this article, we would like to talk about some insights for how to write robust CERs complying with MDR as it seems many manufacturers have been faced many challenges by Notified Bodies (NBs) on their CERs, particularly for transitioning from MDD to MDR. Some seem to be still sticking to the MDD approach to the MDR.
Why is writing the CER under EU MDR challenging?
Compared to the MDD, MDR expects the higher standard for the CER. MedDev 2.7/1 rev4 has not been updated yet according to the MDR 2017/745. Therefore, under the MDR, writers of CERs need to largely rely on their own expertise and insights to prepare the CERs in a way meeting all expectations and standards of the MDR. There are some CER templates available but not all of them fit your specific products as requirements are different by types of devices. If there is a one-fit-all kind of, versatile template, that would make writing of the CER easy and efficient. However, there is none for the moment. There may be at some point some standard templates by certain types of devices.
However, you should understand that the MDR is structured in a way that the CER for the product in question is to be created uniquely fit to the device. This may sound daunting if you are not confident in writing the CER according to the requirements and standards of the MDR.
Some tips for writing a robust CER?
The one thing you should be aware is that reviewers of the NBs are humans and that they are not necessarily experts in the categories of your devices. Therefore, it is not better to take an approach that reviewers should know about medical devices in question when you formulate the CER structure and contents. Therefore, the structure should be easy to navigate. Avoid redundancy. The bookmarks should be added to help reviewers to easily find reference documents. Another thing that you should be careful about is to make sure all documents are consistent including the CER, the IFU, the product catalogue, and other technical documents in terms of words to be used. For example, if terms used in the instruction for use (IFU) are different from the ones in the CER, you would likely receive deficiency feedback from the NBs unless it is obvious to those different words have exactly the same meanings. For the safe sake, it is recommended to use the same terms across all documents.
Another important element is a thorough evaluation on the state-of-the-art (SOTA). Although the MDR 2017/745 does not provide the clear definition regarding the state of the art (SOTA), MDCG 2020-6 provides the definition of SOTA as follows:
Developed stage of current technical capability and/or accepted clinical practice in regard to products, processes and patient management, based on the relevant consolidated findings of science, technology and experience.
Therefore, in order to conduct a thorough SOTA evaluation, you need to evaluate not only you benchmark products but also all alternative therapies/procedures that are currently used for your target indications on the same clinical claims. If this SOTA evaluation is insufficient, you would likely receive deficiency feedback from the NBs.
With respect to the SOTA evaluation, once you defined clinical claims (both performance and safety), you need to define clinical outcomes for each clinical claim with threshold values with which your device in question is to be measured against the SOTA. The threshold values, therefore, need to be based upon the SOTA evaluation.
In the CER, the clinical claims are the most important and core element as they shape the clinical evaluation. If the clinical claims are not well defined, it may be difficult to identify proper SOTA and create appropriate literature search protocol and may deem to be insufficient literature search and SOTA evaluation.
What level of literature search and SOTA evaluation is expected in EU MDR?
Once the clinical claims are defined, you need to identify proper SOTA based upon the clinical claims. The EU MDR requires and expects thorough clinical evaluation. The thorough evaluation means that the literature search needs to be a systematic search with a justifiable protocol including inclusion and exclusion criteria, the search period. It is important to include all search results even no literature found because you need to show that you have done thorough search and evaluation to the NB. Also, doing the thorough search and evaluation helps you identify what clinical evidence is missing or insufficient and therefore need to collect them through PMCF activities if you want to keep those clinical claims including indications.
As mentioned earlier, the EU MDR expects the CER with higher standards compared to the MDD, the writer for the CER needs to be highly skilled and have expertise with good understanding of what the NBs are expecting. If you are not confident, it is highly recommended to consult with an expert.
Eclevar Medtech is a CRO specialized in medtech industries and has extensive experience in preparing CERs under EU MDR. If you have any difficulties with your CERs, please feel free to contact us at clientcare@eclevar.com.
