When the EU Medical Device Regulation (MDR 2017/745) replaced the Medical Device Directive, it didn’t just shift the regulatory framework; it fundamentally changed what a Clinical Evaluation Report needs to demonstrate. And yet, many manufacturers are still submitting CERs that were built for a MDD world. The consequences are significant: delayed CE marking, costly remediation cycles, and in some cases, market withdrawal. Understanding why CERs fail under MDR scrutiny is a competitive and commercial necessity.
5 Core Reasons CERs Fall Short Under MDR
1. Insufficient Clinical Evidence for the Device’s Specific Intended Purpose
One of the most common failure points is using clinical data that doesn’t precisely match the device’s intended purpose as defined in the Instructions for Use (IFU). Under MDR Article 61, clinical evidence must be sufficient in quality and quantity, and “sufficient” now carries a much higher threshold than before.
Generalised literature reviews or vague equivalence claims no longer satisfy a Notified Body. Evidence must be traceable, current, and directly applicable.
2. Weak or Unjustified Equivalence Claims
Demonstrating clinical equivalence under MDR requires meeting strict criteria across three dimensions: clinical, technical, and biological. Many CERs rely on equivalence to predicate devices without sufficient documentation, or worse, without a contractual access agreement to the equivalent device’s data as required under Article 61(5).
If your equivalence claim doesn’t hold up, neither does your clinical evaluation.
3. Outdated or Incomplete Post-Market Clinical Follow-Up (PMCF) Plans
A CER is not a one-time submission. MDR requires it to be a living document, supported by ongoing PMCF activity. Notified Bodies are increasingly scrutinising whether PMCF plans are proactive and device-specific, not boilerplate documents copy-pasted across product families.
4. Missing State of the Art Analysis
MDR explicitly requires a state of the art (SOTA) analysis that contextualises your device’s performance and safety against current clinical knowledge and competing technologies. Many CERs skip this or treat it superficially; a gap that reviewers flag immediately.
5. Poor Alignment with the Risk Management File
Your CER and risk management file (per ISO 14971) must be tightly aligned. Residual risks identified in the risk management process should be directly addressed in the clinical evaluation. Disconnects between these documents are a red flag for any Notified Body auditor.
"A CER isn’t just a document, it’s a scientific argument. If it reads like a literature dump rather than a structured clinical case, it will fail".
What a Compliant CER Actually Looks Like
A CER that stands up to MDR scrutiny is methodologically rigorous, evidence-led, and integrated with your Quality Management System. It includes:
- A clearly defined clinical evaluation plan (CEP) that precedes and informs the CER
- Systematic literature search protocols with reproducible methodology
- A robust benefit-risk analysis tied to specific clinical claims
- Documented PMCF planning with measurable objectives
- Full traceability between clinical evidence, risk management, and labelling
The Cost of Getting It Wrong
A Notified Body rejection has real business implications. Remediation cycles take months. Market timelines slip. Competitors gain ground. And with the MDR transition deadline behind us, there’s no more grace period.
Manufacturers who invest in CER quality upfront consistently achieve smoother certification and stronger post-market positions.
How to Strengthen Your CER Before Submission
- Audit your existing CER against MEDDEV 2.7/1 Rev 4 and MDR Annex XIV requirements
- Verify your equivalence claims with a formal justification document
- Engage clinical experts to review your benefit-risk conclusions
- Align your PMCF plan with your PMCF evaluation report cadence
- Conduct a pre-submission gap analysis with a regulatory consultant
"Most CER failures are preventable. They stem from process gaps, not impossible standards. The manufacturers who succeed treat clinical evaluation as a strategic function, not a compliance checkbox."
Up next
In Blog 2, we will unpack one of the most confused concepts in MDR compliance: the difference between a Clinical Evaluation Plan (CEP) and a Clinical Evaluation Report (CER), and why getting this distinction right is foundational to your regulatory strategy. Learn more about our clinical evaluation services, or reach out to our team to discuss your challenges or questions.