Under MDR (EU) 2017/745, Clinical Evaluation Reports (CERs) are reviewed with significantly increased scrutiny. Based on the review structures commonly used by Notified Bodies (NBs) and the CEAR assessment templates, the following five deficiencies are most frequently identified during conformity assessments.

1. Inadequate Alignment of the Clinical Evaluation Plan (CEP) with Annex XIV

One of the most frequent findings is a CEP that does not fully comply with Annex XIV Part A.

Typical issues include:

• Missing justification for the level of clinical evidence
• No clear identification of GSPRs that require clinical data
• Undefined clinical benefit endpoints
• Weak definition of risk benefit acceptability criteria
• Superficial PMCF planning

Notified Bodies explicitly verify whether the CEP content satisfies the requirements of Annex XIV and MDCG 2020-13. When the CEP is weak, the entire foundation of the CER collapses with it.

2. Insufficient Demonstration of Clinical Safety and Residual Risk Analysis

Another major deficiency relates to a structurally weak clinical safety assessment.

Frequent problems:

• No structured qualitative or quantitative safety analysis
• Residual risks not clearly identified
• Side effects listed without any data based evaluation
• Poor alignment with risk management documentation

NB reviewers typically check whether:

• Clinical safety methods are clearly defined
• Residual risks are properly justified
• Risk benefit remains acceptable under normal conditions of use

A CER that summarizes safety without a structured analysis is often rejected.

3. Weak Equivalence Justification (Annex XIV Section 3)

Equivalence is one of the most misunderstood areas under MDR.

Common NB findings:

• Only technical similarity is demonstrated
• Biological equivalence is not demonstrated
• Clinical equivalence is insufficiently justified
• No access to equivalent device data
• Lack of contract for Class III and implantable devices

MDR requires the simultaneous demonstration of:

• Technical equivalence
• Biological equivalence
• Clinical equivalence

Failure in any of these three pillars results in a major nonconformity.

4. Poor Literature Search Methodology

A CER may contain many references and still fail methodologically.

Typical NB concerns:

• No defined search protocol
• Missing inclusion and exclusion criteria
• No PRISMA flow diagram
• No duplication control strategy
• Lack of discussion of unfavorable data

Notified Bodies evaluate whether the literature review follows systematic and objective criteria such as PRISMA, PICO, or CENTRAL.

Quantity of articles does not replace methodological rigor.

5. Inadequate Integration of PMS and PMCF into the CER

MDR defines clinical evaluation as a living, continuous process.

Frequent deficiencies:

• CER update frequency is not justified
• PMCF is not clearly linked to the identified risks
• PMS data is summarized but not clinically interpreted
• No feedback loop between post market data and the risk benefit conclusion

NB templates explicitly assess:

• PMS Plan reference
• PMCF Plan adequacy
• PSUR integration
• Regularity of updates

A CER disconnected from PMS is considered non compliant under MDR.

Why These Deficiencies Matter

Under MDR, clinical evaluation is no longer a literature summary. It is a structured regulatory argument that demonstrates:

• GSPR compliance
• Clinical safety
• Clinical performance
• An acceptable benefit risk profile
• Continuous post market validation

Notified Bodies assess this through structured CEAR frameworks, which means weaknesses become visible very quickly during the review.