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The difference between PMS and PMCF in one minute

Post-Market Surveillance (PMS) and Post-Market Clinical Follow-up (PMCF)

The Medical Devices Regulation (EU) 2017/745 (MDR) put extra emphases on PMS and PMCF. It basically requires the manufacturer to keep establishing compliance as real life data is actively collected during the lifecycle of the device, as appropriate for each phase of the lifecycle. Medical devices are not static, the context in which they are used keeps changing and so should their design.

I often see companies puzzled by the concepts of PMS and PMCF. First, these are not opposed concepts with one on side and the other on the other side. PMCF is part of PMS. PMCF focusses on non-vigilance related data, while the rest of the PMS processes information coming from incidents and other vigilance related aspects. Take a good look at MDR Article 83(3), especially paragraph (f) on ‘options to improve the usability, performance and safety of the device’. Still, there is a difference in the type of PMS data and PMCF data and how they can be used. In training I use the following example to illustrate the difference between these concepts to make this clear in one minute:

Case of the X-ray devices

About 120 years ago X-rays were discovered as a way to look inside the body without the need to cut them open. However, these machines were very crude with low contrast, lack of detail and often very long exposure times. There are records of patients losing their hair after a picture of their skull had been taken. Still, these devices kept being used as the benefits outweighed the risks (assuming those risks were fully understood at the time).

If we look at modern X-ray equipment we see devices that use limited amounts of radiation, apply scatter grids, collimators, back scatter plates and software for contrast improvement, combined with the introduction of protocols to limit the number of X-ray examinations to a minimum, in order to reduce the levels of radiation patients are exposed to.

Now here is a challenge: can you find in literature ISO 14155 compliant evidence that this type of radiation causes harm? Probably not. As a community we just know this is dangerous, because there have been several events recorded where people died after exposure to high levels of radiation in the late 1800’s and early 1900’s. Now we don’t even accept exposure to devices that were state of the art in the 1960’s, although in those years no events of harm resulting of over exposure were recorded.

In terms of PMS: there are no incidents and no harm can be found in scientific literature (assuming history books with anecdotical records are in general not accepted as sources for clinical evidence).

In terms of PMCF: we see a continued attempt to reduce exposure, resulting in a gradual shift in acceptable levels of radiation as state of the art.

So, here you have an illustration of the difference between PMS and PMCF in one minute.


This is just an example of how I setup my trainings. I make use of many illustrations of complex concepts so they really stick and I have loads of real life examples collected during my career of almost 40 years in the medical devices industry. Go to my training page, or reach out directly if you want to discuss training for you, or for your organization.