Clinical Evaluation Under EU MDR: What It Is and Why It Matters

Clinical evaluation is not a document you produce once and file away. Under EU MDR, it is an ongoing process — one that has to be built into how you manage your device across its entire lifecycle. If your team is approaching this as a one-time CER write-up, the part that catches most people off guard is that the regulation expects you to keep updating it, and your Notified Body will expect to see evidence of that.

What clinical evaluation actually means under MDR

The purpose of clinical evaluation is to demonstrate that your device achieves its intended purpose, that the clinical benefits outweigh the risks, and that the device performs as claimed — all based on clinical data. That clinical data can come from clinical investigations, published literature on your device or equivalent devices, or post-market clinical follow-up. In practice, most manufacturers rely heavily on literature for initial CE marking, and then lean on PMCF data to keep the evaluation current.

Annex XIV of MDR lays out the requirements in two parts: Part A covers the clinical evaluation process itself, and Part B covers post-market clinical follow-up. The Clinical Evaluation Report (CER) is what documents the process and its conclusions. But the CER is the output of the evaluation — the evaluation itself is the structured, methodical analysis that precedes it.

How MDR raised the bar compared to MDD

Under the old MDD, clinical evaluation requirements were less prescriptive. Many legacy devices made it to market on thin clinical data — sometimes just a literature review and a declaration of equivalence with a predicate device. MDR closed a lot of those doors. The criteria for claiming equivalence are now significantly stricter (same intended purpose, same design, same biological characteristics), and for higher-risk devices, Notified Bodies are expected to scrutinise clinical evidence much more closely.

One thing that changed significantly: you can no longer claim equivalence with a competitor's device unless you have contractual access to their technical documentation. This effectively shut down a route that many manufacturers had relied on under MDD. If your team is mid-way through a legacy transition and equivalence was the plan, this is worth revisiting now.

Where clinical evaluation fits in your documentation

The CER does not stand alone. It connects directly to your General Safety and Performance Requirements (Annex I), where you have to demonstrate that your device meets each GSPR with a mix of clinical and non-clinical data. A well-structured clinical evaluation maps its conclusions back to the relevant GSPRs, so that reviewers can trace the clinical evidence through the full documentation set.

It also connects forward to your post-market surveillance system. PMCF feeds new clinical data back into the CER. The PMCF Evaluation Report is the mechanism for that — it documents what PMCF activities produced, and it triggers updates to the CER when new data changes the benefit-risk picture.

What a Notified Body looks for

When a Notified Body reviews your clinical evaluation, they are not just checking that the CER is there — they are checking whether the methodology was sound. Did you define a clear search strategy for literature? Did you appraise the quality of the studies you included? Did you address contradictory evidence? Did you justify your equivalence claims, if you made any?

The MDCG guidance documents — especially MDCG 2020-5 on clinical evaluation and MDCG 2020-6 on equivalence — set the methodological expectations that auditors are trained against. Reading those documents alongside your internal CER template is the fastest way to spot gaps before your Notified Body does.

Where to go from here

This overview is the entry point. The other resources in this category go deeper: how to structure your CER, how equivalence works under MDR specifically, what your PMCF plan needs to include, and how to read the MDCG 2020-5 guidance as a practitioner rather than a regulator. If you are new to clinical evaluation, read this first and then work through the rest in order.