Medical Device Equivalence: How Close Does It Need to Be Under the EU MDR and MEDDEV 2.7/1 rev 4?

While there are several new requirements related to clinical evaluation report content contained in MEDDEV 2.7/1 rev 4 and the MDR, one of the more perplexing issues concerns the issue of equivalency.

Companies selling devices that complied with the old Medical Devices Directive 93/42/EEC long used existing scientific literature and equivalent device statements in their CERs. The purpose of doing so was to avoid having to conduct redundant pre- or postmarket clinical studies that prove safety and performance. However, the very definition of equivalent was not specified in the Medical Devices Directive (93/42/EEC), leaving much room for interpretation.

Under the MDR, there is clear text stating that clinical data being leveraged by an organization must be for an equivalent or similar device. While the MDR does not define parameters for determining equivalence, the guidance document MEDDEV 2.7/1 rev 4 has distinctly identified criteria for evaluation of an equivalent device to be used as clinical evidence. As a result, companies are currently facing the following types of issues for situations that are now arising from review of equivalent devices:

• The equivalent or similar device used for comparison is not CE Marked or sold in Europe.
• The technology or material composition is spread across three or four different devices.
• Simple statements that devices are equivalent were made without addressing all technological, biological, and clinical aspects.
• There is no discussion of any differences between the subject device and an equivalent device that may impact safety or performance characteristics.

What qualifies as an equivalent medical device under the EU MDR?

Regarding Section 3 of Annex XIV, the MDR mandates that the device to which you claim equivalency must share the same technical, biological, and clinical characteristics. If, for example, the device to which you are comparing yours has the same technical and clinical characteristics but uses different materials (in a biological interaction sense), that won’t work. Two of the three is not good enough. This is why having a thorough scientific literature search protocol is so incredibly important now, along with identification of a suitable equivalent device. This will greatly expand the need for a complete and well-defined scientific literature search, because different materials may be acceptable but a justified rationale against safety and performance must now be completed.

The requirements for technical, biological, and clinical characteristics are further defined in Appendix A1 of MEDDEV 2.7/1 rev 4. People often ask us if devices that do NOT have CE Marking can be used for equivalency. The initial answer is generally no; however, it is theoretically possible you would have to (a) make a very good case to your Notified Body why the data is transferrable to an EU population and (b) conduct an analysis of safety and performance gaps related to the clinical performance. Ultimately, you may have to perform a clinical investigation.

By the way, you will also need to find, locate, and gather evidence or data from the equivalent device for every feature you claim as equivalent. Thats not always easy, so you might end up having to acquire the competitive device or hope their instructions for use have enough detail about the device itself!

Show me the data

While the basic rules for claiming equivalency have not changed dramatically from MEDDEV 2.7/1 rev 3 to rev 4, the requirements for proving it to your Notified Body have increased. There was much more flexibility in the past for equivalent or similar devices, but rev 4 of MEDDEV 2.7/1 has clarified what is meant by equivalent device and Notified Bodies are following this closely now. The simplest way to show equivalency to an existing CE Marked product on the market in the European Union is to create a tabular listing supporting technical, biological, and clinical characteristics.

This goes back to the previous statement and showing data that demonstrates how the two devices are equivalent. In some situations, you may not have data available for an equivalent or similar device it will then be a matter of supporting those gaps with clinical literature and risk management that proves the safety and performance of your device is equivalent to those already on the market. If this cannot be done, then a clinical investigation and/or a postmarket clinical follow-up may be needed.

Remember that stats class you took? Youll finally get to use it.

As you pull together all this new clinical data, remember that revision 4 of MEDDEV 2.7/1 also requires you to demonstrate the validity of your data. Simple percentages are no longer enough you must use common statistical techniques (mean, standard deviation, etc.) when making assertions about risk-benefit, claims, and so on. Simple statements that the risk-benefit is acceptable, as you may have made in the past, will no longer be accepted as an approach. Your declarations may need to take available quantitative data into consideration.

Another factor to consider in claiming equivalence is the composition of the patient population, as the regulatory hurdle has been raised significantly on this as well. If the comparison data you are using in your CER was gathered outside Europe and there are considerable differences in patient weight, age, gender, physiology, etc. you might have a hard time justifying equivalence to your Notified Body. For example, if you are comparing to a device approved in Japan that is not CE Marked, it would be hard to convince a Notified Body that the population characteristics of the Japanese are close enough to European populations.

So what’s a manufacturer to do?

Assuming you cannot obtain the necessary technical, biological, or clinical data from your competitors device, it may be possible to demonstrate equivalency through performance testing (provided that you can obtain the competitors device for testing). Material characterization and comparative testing should be done in compliance with ISO 10993. Some products may have other established recognized international or national standards that can be tested against, which could preclude comparative testing.

The MDR changes are especially problematic for high-risk and implantable devices. Common implants such as stents, hip implants, and knee implants have long relied on published scientific data, but those manufacturers may now be faced with conducting their own Post Market Clinical Follow-Up (PMCF) studies or other proactive postmarket surveillance activities to meet CER requirements. This is causing great angst for many manufacturers who have high-risk and implantable devices that have been on the market for years but have not performed a clinical investigation they are now struggling to determine if there is enough clinical data to keep their devices on the market.

Crossing your fingers is not a viable strategy

Some companies are hoping their existing clinical data will pass muster during a future EU MDR Notified Body audit. Thats a hugely risky approach. The best approach is to openly engage with your Notified Body and share your concerns and questions about equivalency and ask for their opinion on what needs to be done. Oriel STAT A MATRIX can assist with this too. We help many medical device companies compile new CERs, examine current ones, perform literature searches, and conduct an entire risk-benefit analysis against the safety and performance requirements.