What is a clinical evaluation report (CER)?

In short: The CER is the document at the core of your technical file: a systematic appraisal of clinical evidence — your own data, equivalent-device data, and literature — demonstrating your device is safe and performs as intended. Notified Bodies read it critically; a weak CER is among the most common causes of findings.

What the CER has to demonstrate

Required by MDR Article 61 and structured per Annex XIV, the CER pulls together every source of clinical evidence bearing on your device — clinical investigation data you've generated yourself, data from an equivalent device already on the market, and a structured literature review — into a single, reasoned appraisal that your device achieves its intended performance without unacceptable risk. It isn't a literature summary; it's an argument, and Notified Bodies scrutinise the logic connecting the evidence to the conclusion at least as closely as the evidence itself.

Two routes to sufficient evidence

Broadly, you either generate clinical data yourself (a formal clinical investigation, appropriate for genuinely novel devices or higher classes) or rely on equivalence — demonstrating your device is clinically, technically, and biologically equivalent to a device already supported by adequate published data — supplemented by a systematic literature review. Which route fits depends heavily on your device's novelty and class: a Class IIa product with a reasonably well-established mechanism can often build a defensible equivalence case; a genuinely new approach usually can't. One constraint before banking on equivalence: for implantable and Class III devices, MDR Article 61(5) requires a contract giving full access to the equivalent device's technical documentation — effectively ruling out equivalence to a competitor's device without their cooperation.

Why it's the most common source of findings

A CER that reads as a literature summary rather than a reasoned appraisal — evidence cited without a clear line back to your specific device's safety and performance claims — is one of the most frequent gaps Notified Bodies flag. The fix isn't more literature; it's tighter reasoning connecting each piece of evidence to a specific claim your device makes, and being explicit about where evidence is thinner and why that's still acceptable.

The CER isn't a one-time deliverable — it's tied to post-market clinical follow-up (PMCF) and needs updating as new evidence and real-world data come in after launch.

Where next: Building an MDR Technical File and CER · What actually goes into a technical file?

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