Your MDD Certificate Expires: Now What’s Missing in Your CER?

Written by HATEM RABEH, MD, MSc Ing

Your Clinical Evaluation Expert And Partner

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I’ve reviewed transition files where teams added an MDR cover page to an old CER and called it done. The Notified Body rejected it in the first round. The manufacturer was surprised. They had clinical data. They had a literature review. What went wrong?

The issue was not the data. It was the framework. MDD allowed a level of flexibility that MDR does not recognize. The transition is not a format change. It’s a structural rebuild.

Why Gap Analysis Is Not Optional

Under MDD, clinical evaluation was often treated as a standalone document. The expectations were less prescriptive. Equivalence could be claimed with moderate justification. Literature searches were less systematic. PMCF was an afterthought in many cases.

MDR changed the standard. Clinical evaluation is now the backbone of technical documentation. It must be current, continuously updated, and directly linked to risk management, design verification, and post-market surveillance.

If your CER was written before 2021, it almost certainly does not meet MDR expectations. The gap analysis is how you identify what needs to be rebuilt, not revised.

Where the Real Gaps Hide

The obvious gaps are easy to spot. Missing PMCF plan. No literature search protocol. Outdated references. Those get fixed quickly.

The hidden gaps are structural. They sit in how the clinical evaluation was conceived, not just how it was written.

Equivalence Claims That No Longer Stand

Under MDD, equivalence was often claimed with limited justification. A competitor device. Similar materials. Comparable intended use. The bar was lower.

MDR raised it significantly. Annex XIV Part A requires demonstration of technical, biological, and clinical equivalence. If any characteristic differs, equivalence cannot be claimed. If the equivalent device does not have robust clinical data, the claim collapses.

In transition gap analysis, equivalence is the first place to look. If your MDD CER relied on equivalence, ask whether that claim survives MDR scrutiny. Most of the time, it does not.

Literature Reviews That Lack Methodology

MDD did not require a systematic literature review protocol. Many CERs included a literature section without explaining how articles were identified, selected, or appraised.

MDR expects systematic methodology. The search strategy must be documented. Inclusion and exclusion criteria must be defined. The appraisal process must be transparent. The literature must be recent, typically within the last five years unless justified.

In gap analysis, check whether your literature review follows a protocol. If not, it must be redone. A simple narrative literature section is no longer acceptable.

PMCF as a Real System, Not a Placeholder

Under MDD, PMCF plans were often generic. They described potential activities without commitment. There was little enforcement of implementation.

MDR treats PMCF as mandatory and enforceable. The plan must define specific methods, timelines, and responsibilities. It must be linked to the clinical evaluation and updated based on findings. The PMCF report must feed back into the CER in a documented cycle.

If your MDD file has a PMCF plan that was never executed, the gap is not just documentation. It’s operational. You need to build a real PMCF system before transition approval.

How to Conduct the Gap Analysis

The gap analysis is not a checklist. It’s a structured comparison between what you have and what MDR requires.

Step 1: Map MDR Requirements to Existing CER Sections

Start with Annex XIV Part A and MDCG 2020-5. List every required element. Then map each element to a section in your current CER.

Where there is no corresponding section, you have a gap. Where the section exists but lacks depth, you have a gap. Where the section is outdated, you have a gap.

This mapping is mechanical but revealing. It shows not just what’s missing, but where the document was built on a different logic.

Step 2: Evaluate the Quality of Clinical Data

MDR expects clinical data to be sufficient in amount and quality. Sufficient means adequate to demonstrate safety and performance for the intended use and patient population.

Review your clinical data sources. Are they recent? Are they specific to your device or are they general literature about the technology? Do they cover all intended uses and all relevant patient groups?

If your data is thin, generic, or old, the gap is evidence generation. This is not solved by rewriting. It requires new studies, registries, or PMCF data.

Step 3: Check Integration with Risk Management

Under MDD, clinical evaluation and risk management were often parallel tracks. They referenced each other but were not deeply integrated.

MDR requires integration. The clinical evaluation must address residual risks identified in risk management. It must evaluate whether clinical data confirms the risk analysis. If new risks emerge from clinical data, they must feed back into the risk management file.

In your gap analysis, check whether the CER and risk management file are truly linked. If not, this is a structural gap that requires rework of both documents.

Step 4: Assess SOTA Against Current Evidence

The state of the art is not static. What was SOTA in 2015 is not SOTA in 2025. MDR requires that the clinical evaluation reflects current medical knowledge and technology.

Review your SOTA section. Is it based on recent literature? Does it reflect current clinical practice? Does it acknowledge advances in the field that may affect your device’s risk-benefit profile?

If your SOTA is outdated, the gap is not cosmetic. It affects how reviewers assess whether your device meets current standards of care.

What Notified Bodies Look for in Transition Files

Notified Bodies expect to see a clear narrative of what changed and why. They want to understand how you identified gaps and how you closed them.

They do not accept minimal updates. They do not accept copy-paste from guidance documents. They expect evidence that you conducted a real analysis and made real changes based on findings.

In my experience, the files that pass transition review are those where the gap analysis is visible. The manufacturer documented what was missing, what was added, and what was updated. The logic is transparent.

The files that get rejected are those where the manufacturer tried to minimize the work. They updated dates, changed some wording, and hoped it would pass. It does not.

Timing and Resource Reality

The transition deadline is fixed. The amount of work required is not. For many manufacturers, the gap analysis reveals more work than anticipated.

If your gaps include missing data, you cannot fix that in weeks. Data generation takes months, sometimes years. If your equivalence claim is invalid, you may need clinical investigations.

The gap analysis must be done early enough to allow time for real corrections. Starting six months before your certificate expires is too late if the gaps are structural.

Allocate time not just for writing, but for data collection, risk management updates, and PMCF implementation. The CER is the output. The work is upstream.

Practical Steps to Start

Pull your current CER and the MDR checklist from MDCG 2020-5. Go through line by line. For each requirement, ask: do we have this, is it current, is it sufficient?

Document every gap. Classify them: documentation gaps, data gaps, process gaps. Prioritize based on regulatory impact and time required.

Build a transition plan that assigns responsibility and deadlines. The gap analysis is not the end. It’s the diagnosis. The plan is the treatment.

Engage your Notified Body early. Share your gap analysis and ask for feedback. Many Notified Bodies will provide input on whether your understanding aligns with their expectations. This reduces the risk of rejection later.

Final Thoughts

The MDD to MDR transition is not about making your old CER look new. It’s about confronting what was acceptable then and is not acceptable now.

The gap analysis reveals where the logic has to change. It shows where assumptions no longer hold. It exposes where the evidence is thin.

The manufacturers who treat this as a serious exercise will build CERs that survive review. Those who treat it as a formality will face rejection, rework, and delays.

The deadline is not flexible. The work is real. Start with an honest gap analysis, and let it guide the rebuild.

Peace,
Hatem
Clinical Evaluation Expert for Medical Devices
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