Clinical Claims Under MDR: The Evidence Gap Nobody Talks About

Written by HATEM RABEH, MD, MSc Ing

Your Clinical Evaluation Expert And Partner

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This scenario repeats across hundreds of MDR submissions. Clinical claims appear in labels, marketing materials, and instructions for use. But when reviewers trace them back to the clinical evaluation report, the evidence is either missing, indirectly related, or misinterpreted.

The problem is not that manufacturers lie. The problem is that most organizations do not have a structured process to identify, document, and substantiate every single clinical claim they make.

Under MDR Article 61 and Annex I, every claim about clinical performance, safety, or benefit must be supported by clinical data. This is not a suggestion. It is a regulatory requirement that Notified Bodies enforce systematically.

What Qualifies as a Clinical Claim

Before you can substantiate a claim, you need to recognize it. Many manufacturers underestimate how broad the definition is.

A clinical claim is any statement, explicit or implied, about what the device does in a clinical context. This includes statements about safety, performance, clinical benefits, patient outcomes, or comparisons with other treatments.

Examples of clinical claims:

• ‘Reduces pain by 40% within 24 hours’
• ‘Suitable for use in diabetic patients’
• ‘Non-inferior to surgical repair’
• ‘Minimally invasive approach’
• ‘Faster recovery compared to conventional treatment’

Each of these statements requires clinical evidence. Not assumptions. Not engineering data. Clinical evidence.

The consequence is not just a delay. It is a signal to the auditor that the clinical evaluation process is not integrated with labeling, regulatory strategy, and quality management.

Where Clinical Claims Hide

Most manufacturers focus on obvious claims in marketing brochures. But claims appear in many places, and each one must be substantiated.

Common locations where clinical claims appear:

• Instructions for use
• Labeling and packaging
• Product catalogs
• Clinical evaluation reports (explicitly or implicitly)
• Intended purpose statements
• Risk-benefit analysis
• Design verification and validation reports
• Technical file summaries

I have seen cases where a claim was buried in a design validation report, never formally reviewed in the CER, but referenced by the Notified Body during assessment.

If your organization does not have a centralized register of all clinical claims, you are operating blind.

What Substantiation Actually Means

Substantiation is not about having clinical data. It is about demonstrating that the data directly supports the specific claim being made.

This requires three elements:

1. Relevance: The clinical data must address the exact clinical outcome or performance measure stated in the claim.

2. Quality: The data must come from studies or sources that meet the appraisal criteria outlined in MDCG 2020-5 and MDCG 2020-6.

3. Traceability: The CER must explicitly reference the data, explain how it supports the claim, and address any limitations or gaps.

Let me give you a real example. A manufacturer claimed their catheter ‘minimizes vascular trauma.’ The CER referenced a study showing reduced insertion force. The Notified Body rejected it. Insertion force is a mechanical surrogate. Vascular trauma is a clinical outcome. The data did not substantiate the claim.

The MDCG Framework for Clinical Evidence

MDCG 2020-13 and MDCG 2020-6 establish the requirements for clinical evidence and equivalence. These documents define what counts as sufficient evidence and how to structure the appraisal.

For substantiation, the key is in Section 5 of MDCG 2020-13, which outlines how to evaluate clinical data and link it to intended purpose and claims.

The Notified Body will ask:

• What claim is being made?
• What clinical data supports it?
• Is the data from the device under evaluation or from an equivalent device?
• If from an equivalent device, is equivalence demonstrated according to MDCG 2020-6?
• Does the data quality meet the appraisal standards?
• Are there conflicting data or limitations?

If any answer is unclear, the substantiation fails.

I have reviewed CERs where the manufacturer listed five studies but never explained which study supported which claim. The Notified Body issued a major non-conformity. The manufacturer had to rewrite the entire analysis section.

The Claim-Evidence Matrix

One of the most effective tools I use in clinical evaluation is a claim-evidence matrix. It is a simple table that maps every clinical claim to its supporting evidence.

The matrix includes:

• The exact wording of the claim
• The document where the claim appears
• The clinical data source (study, publication, PMCF, equivalence)
• The CER section where the substantiation is documented
• Any limitations or gaps

This matrix becomes the backbone of the clinical evaluation and the first reference during audits.

When a Notified Body asks, ‘How do you substantiate this claim?’ you point to the matrix, then to the CER section, then to the data. The answer is immediate and traceable.

What Happens When Claims Cannot Be Substantiated

If you cannot substantiate a claim, you have three options.

Option 1: Remove the claim. This is the fastest solution but may affect market positioning or labeling strategy.

Option 2: Generate new clinical evidence. This means conducting a clinical investigation, running a PMCF study, or performing a literature review focused on that specific claim.

Option 3: Reframe the claim. Sometimes the data supports a narrower or more specific statement. Instead of claiming ‘faster recovery,’ the data may support ‘reduced time to ambulation in controlled studies.’

Each option has consequences for timelines, budgets, and regulatory strategy.

What you cannot do is leave the claim unsubstantiated and hope the Notified Body does not notice. They will notice. And when they do, the review stops.

How to Build a Substantiation Process

Substantiation is not a one-time exercise. It is a continuous process that must be integrated into product development, labeling, and post-market surveillance.

Here is the structure I recommend:

Step 1: Identify all clinical claims. Review every document in the technical file where claims might appear. Build the initial claim register.

Step 2: Trace each claim to clinical data. For every claim, identify the data source. If no source exists, flag it as a gap.

Step 3: Appraise the data quality. Use the MDCG 2020-5 appraisal criteria to evaluate whether the data is sufficient.

Step 4: Document the substantiation in the CER. Each claim must be explicitly addressed in the clinical evaluation, with clear references to the supporting data.

Step 5: Update the claim register. Every time a label changes, a new study is completed, or PMCF data is generated, update the register and the CER.

This process becomes part of the quality management system. It is not optional. It is the only way to ensure compliance and avoid audit findings.

The Role of PMCF in Ongoing Substantiation

Under MDR Article 61 and Annex XIV Part B, PMCF is not just about confirming safety. It is also about confirming that clinical claims remain valid throughout the lifecycle of the device.

This means your PMCF plan should include objectives that directly relate to your clinical claims.

If you claim a device reduces infection rates, your PMCF should track infection rates. If you claim faster recovery, your PMCF should measure recovery time.

PMCF data feeds back into the CER during periodic updates. If the data contradicts a claim, you must either revise the claim or explain the discrepancy.

I have seen manufacturers whose PMCF data showed no benefit on the claimed outcome. The claim had to be removed from the label. The alternative was to continue making an unsubstantiated claim, which is a regulatory violation and a legal risk.

Final Reflection

Substantiating clinical claims is not about regulatory compliance alone. It is about intellectual honesty. Every claim you make is a promise to clinicians and patients. If you cannot back it with evidence, you should not make it.

The MDR has raised the bar. Notified Bodies and competent authorities are trained to look for unsubstantiated claims. They will find them. And when they do, the consequences affect timelines, market access, and reputation.

The solution is not complex. Build a claim register. Map every claim to clinical evidence. Update it continuously. Integrate it into your CER and your quality system.

Do this, and substantiation becomes a strength, not a weakness.

In the next part of this series, I will address how to handle claims when equivalence is the only data source—and why most equivalence arguments fail under scrutiny.