A Clinical Evaluation Report (CER) is the central evidentiary report on the clinical evaluation of a medical device. It summarises the clinical data, assesses their probative value and derives from this whether safety, clinical performance and – where applicable – the clinical benefit of the device are adequately demonstrated. The CER is therefore a core document of the technical documentation and an essential element for conformity assessment by the Notified Body.
Positioning, purpose and EU context
Under the EU Medical Device Regulation (EU) 2017/745 (MDR), clinical evaluation is an ongoing process throughout the entire product lifecycle. The CER documents this process in a traceable and auditable manner: from the clinical question through data collection to the conclusion. For manufacturers, the CER is also a steering instrument, as it shows which evidence gaps exist and whether additional clinical data – for example from a clinical investigation or from Post-Market Clinical Follow-up – are required.
Content, structure and methodology
In projects, the CER is often maintained as the “master document” of clinical evidence, holding together several accompanying deliverables consistently. These include, for example, search protocols and screening lists from the literature review, evidence quality appraisal sheets, a claim-to-evidence traceability matrix and – depending on the product – reports on clinical investigations or PMCF. A well-structured CER not only facilitates review by the Notified Body but also reduces internal coordination effort, as changes to the product and labelling can be checked more quickly for their clinical relevance.
A robust CER follows a clear logic: first, the product description, intended purpose, target population, clinical claims and the state of the art are described. The relevant clinical data are then identified (e.g. literature, clinical investigations, registry data, vigilance information) and selected according to defined criteria. These data are subsequently critically appraised, synthesised and compared against the safety and performance requirements. The report concludes with reasoned conclusions, including an assessment of the benefit-risk ratio and the derivation of a plan for ongoing updates.
- Product and indication description including clinical claims
- State of the art and comparison with alternatives
- Search strategy, selection criteria and data sources
- Critical appraisal of evidence quality (bias, transferability, endpoints)
- Overall synthesis, benefit-risk and residual risks
- Conclusions, open evidence gaps and update plan
Distinction from clinical investigation and PMCF
The CER itself is not a study report but the appraisal and conclusion framework. It may include clinical investigations as a data source, but this is not mandatory if sufficient clinical evidence can be demonstrated by other means. At the same time, a CER frequently leads to the conclusion that additional data are needed – for example through a clinical investigation or through Post-Market Clinical Follow-up (PMCF). PMCF is the structured collection of data after placing on the market, in order to keep the clinical evaluation up to date and to answer new questions arising from the market phase, for example regarding rare events or specific subgroups.
Common practical errors and frequent findings
Recurring weaknesses are noted in audits and conformity assessments. These include unclear clinical claims, missing or unjustified endpoints, a literature review without a traceable methodology, and conclusions that are not cleanly derived from the data. Also critical is excessive reliance on equivalence assumptions without adequately demonstrating technical, biological and clinical equivalence. For manufacturers and involved service providers (e.g. Regulatory Affairs, Clinical Affairs, Medical Writing), a strict traceability approach is therefore helpful: every statement in the CER should be traceable to a source or to a documented assessment.
Regulatory references and practical embedding
An interdisciplinary approach is essential for the preparation and maintenance of the CER: Clinical Affairs provides the clinical argumentation, quality management ensures the processes and document control, and Regulatory Affairs translates the Notified Body’s requirements into concrete deliverables. In outsourcing set-ups, this work is often combined with Medical Writing and specialised CRO teams. A common success factor is a pre-agreed CER outline that takes into account the Notified Body’s expectations and clearly describes the interfaces with PMS, PMCF and risk management.
Handling changes is also practically relevant: for product updates (e.g. material changes, a new software version, an additional indication), it must be assessed whether the clinical evidence continues to hold or whether an update to the literature review, an updated data analysis, or additional clinical data are required. A traceable decision matrix helps to justify the need for updates consistently and reduces review cycles.
The CER must be consistent with the technical documentation, the risk management file and the post-market surveillance planning. In particular, the interfaces with risk management (e.g. ISO 14971 in practice) are important: clinical data must address the identified risks, and residual risks must be assessed in the benefit-risk context. For the MDR, the requirements on clinical evaluation and PMCF are also decisive, including the associated guidance documents. In projects, a clear update cadence is recommended (e.g. in the event of significant changes, new safety information, or at defined intervals) so that the CER fulfils the MDR’s lifecycle approach.
FAQ
When is a Clinical Evaluation Report (CER) required?
A CER is generally required for medical devices in the EU, as it documents the clinical evaluation. The scope and depth depend on the risk class, intended purpose, degree of novelty and available evidence.
Is literature alone sufficient as clinical evidence for the CER?
This is possible if the literature is sufficient, current and methodologically robust for the specific intended purpose. In many cases, the Notified Body requires supplementary data, for example for innovative devices or where the transferability of the literature is insufficient.
How often must a CER be updated?
The CER must be kept continuously up to date. Updates are typically envisaged in the event of new safety information, product changes, relevant market observations, or at defined intervals as part of post-market surveillance.