Page Last Reviewed: 3 January 2025

Clinical evaluations are mandatory for all medical devices marketed in Europe under the EU Medical Device Regulation (MDR, 2017/745). The minimum requirements for clinical evaluations are described in Annex XIV, part A, of the MDR and further guidance is provided in MEDDEV 2.7 rev 4.

The output of the clinical evaluation is the Clinical Evaluation Report (CER). It documents 1) your clinical evaluation process and its conclusions, demonstrating the acceptability of the device’s benefit-risk profile and 2) the device’s continued safety and efficacy.

A CER is required for all risk classes, even Class I “self-certified” devices. It is a key component of your European Technical Documentation File, will be reviewed by your Notified Body (if applicable), and is an essential step in obtaining CE Marking.

Clinical Evaluation Report: The Basics

CERs are one of the most time-consuming and challenging regulatory requirements under the EU MDR. You will barely finish and release one report before you are starting the next one. Many medical device manufacturers will consistently have a CER in the pipeline.

When should you start preparing your CER?

The initial preparation can begin during the development phase of your medical device and the creation of its associated technical documentation.  That said, the CER must be continually updated throughout the device’s lifetime with data from the products on the market, any new scientific literature available, and other relevant updates. The CER is a ‘living’ document.

Clinical Evaluation Process

Developing and writing a Clinical Evaluation Report (CER) consists of the following steps:

Development, Writing, and Maintenance

Stage One – Device Development

During the initial development of the device, manufacturers must determine what kind of data should be generated for the CER. Then, what must be collected once the device is on the market. You can also begin making any initial equivalence justification, if claiming equivalence to another device as the basis for the CER. This is also where you first get a sense regarding the strength of connection between all the different documents used in the clinical evaluation.

Stage Two – Drafting of CER

The clinical evaluation report is developed before  conformity assessment review by a Notified Body (if required) and obtaining CE marking. The intent of the final CER is to demonstrate compliance with the MDR’s General Safety and Performance Requirements, and to identify any gaps in the device documentation that must be systematically and continuously assessed.

Stage Three – Continuous Assessment

This occurs throughout the device’s lifetime. High-risk devices must update their clinical evaluation report annually, while lower risk devices must update their reports every two to five years. During these updates, the market behavior of the device is assessed, i.e., the behavior of the device during daily intended use. The continued acceptability of the benefit-risk profile must be confirmed.

Types of Clinical Data

The clinical data included in the CER depends on the risk-classification and novelty of the medical device in question. Higher-risk devices, novel devices, and devices for which there is little to no experience with the technology in the market, are more likely to require clinical investigation data. In contrast, lower risk devices and well-established device technologies can typically rely more heavily on scientific literature and regulatory database (adverse event) information.

‘State of the Art’

Per the MDR, manufacturers must take “into consideration the state of the art”. While ‘state of the art’ is not a legally defined concept in Europe, it is generally considered to be what is currently and generally accepted as good practice in technology and medicine. This does not necessarily mean the most technologically advanced solution. However, it is generally the state of current technical capability, and/or accepted clinical practice, regarding products, processes, and patient management. And it is based on the consolidated findings of science, technology, and experience. Therefore, the CER should show that it considered what is generally acknowledged as ‘state of the art’ for that type of device and procedure.

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Clinical Evaluation Report Structure

Current European CER guidance (MEDDEV 2.7 rev. 4) suggests a structure that meets the minimum compliance requirements. The following sections outline the suggested structure.

It is important to remember that both favorable and non-favorable information must be included in the clinical evaluation report for it to be objective and non-biased.

Executive summary

The executive summary provides a high-level overview of the CER and should:

Scope of the Clinical Evaluation (Clinical Evaluation Plan)

The scope of the clinical evaluation report is established in the Clinical Evaluation Plan (CEP). The CEP serves as a guide for the clinical evaluation process. It also identifies any changes to the clinical data that may have occurred and/or need to be addressed since that last clinical evaluation update.

At a minimum, the scope should include:

Additional Resource: Clinical Evaluation Plans: How to get it right

Clinical Background, Current Knowledge/State-of-the-art

The clinical background and state-of-the-art sections are sometimes considered tedious due to the heavy literature search and review required. Nevertheless, it is an important part of the CER, as it establishes if the medical device aligns with similar devices and current best practice.

Clinical Background

The clinical background section must include a clear identification and description of any relevant medical field(s) and medical conditions associated with the device (and therefore covered by the report).

Literature Search Strategy & Current Knowledge/State of the Art

This section includes a summary and justification of the literature search strategy. The literature search is a key element of the CER, especially where no clinical investigation is conducted. Further explanation on the literature search protocol can be found here.

The literature search is used to retrieve information on the current knowledge of the device/similar devices and the state-of-the-art information. The search protocol defines the sources for the literature (e.g., regulatory databases and online journals), search questions and terms, selection criteria for articles, results, and other relevant items. The details regarding the literature search can also be provided separately in a literature search report and then summarized in the CER.

The state-of-the-art section is largely comprised of the following items:

Clinical Benefits and Risks

The clinical background section must contain 1) descriptions of the device’s clinical benefits and risks, 2) an explanation on the acceptability of the risks and 3) any other undesirable side-effects.

Device Under Evaluation

Type of Evaluation

This section specifies what sources of clinical information are under evaluation within the CER. Sources may include scientific literature, clinical trials, or any mix of all the different types of clinical data available.

Equivalence

This section includes justification, if the device is claiming equivalence to another product already on the market. Note that you cannot claim equivalence to a device unless you have access to that device’s entire technical file. This includes all pre-clinical tests, and any other regulatory documents needed to demonstrate equivalence.

If manufacturers do not have access to the above details for a specific device, they should instead consider the product a ‘similar’ (not equivalent) device in the CER. In most cases, comparison to similar devices is accepted, especially for low-risk devices and products without novel technology. Comparison to similar devices can generally be achieved with information that is publicly available.

If you are unsure whether a comparison to similar devices would be sufficient for your CER, you can discuss your proposed strategy with your Notified Body.

Types of Clinical Data

This section lists the types of clinical data generated and held by the manufacturer. Types of data may be clinical investigations, post-market surveillance, vigilance, and post-market clinical follow-up. 

This section can also include a summary and justification of the literature search strategy used to obtain the clinical data for your medical device and similar devices.  

Summary and Appraisal of Clinical Data

The manufacturer must appraise each piece of clinical data. This should be based on the methodological quality and relevance of the data, and be systematic and unbiased.

The purpose is to assess if the data is 1) suitable (quality and relevance), and 2) contributes to the assessment of the clinical safety and performance of the device.

Many methods can be used for appraising clinical data; however, the most commonly used is, arguably, the appraisal method described in Appendix D of the International Medical Device Regulators Forum (IMDRF) report Clinical Evaluation: Study Group 5 Final Document SG5/N2R8. This method describes a simple grading system for appraising the suitability of the data sets, and the data’s contribution to the demonstration of performance and safety.

Both the clinical data generated by the manufacturer and the scientific literature (and other clinical data identified through the literature search) should be appraised.

Examples of studies that lack the scientific validity to demonstrate clinical safety and performance are those that:

Analysis of clinical data

Now that you have identified and appraised the clinical data, you must analyze it. The data must be analyzed on four key parameters: 1) safety, 2) performance, 3) acceptability of side-effects, and 4) acceptability of the benefit-risk profile.

Each section must summarize how the data demonstrates conformity with the applicable General Safety and Performance Requirements.

Safety Requirements

Includes an analysis of whether:

Performance Requirements

The key element of this section is to demonstrate that there is:

Other details may need to be included based on the device type.

Acceptability of Undesirable Side Effects

Assessment of whether the available clinical data is sufficient to:

Acceptability of the Benefit-Risk Profile

Summarization of the overall experience with the device in the market, including:

This information should be held up against the clinical benefits and safety and performance claims to determine that the benefit-risk profile is, and continues to be, acceptable.

Conclusions

All the data included in the report is summarized in this section and a conclusion is drawn on the acceptability of the CER.

It should include a clear statement regarding the device’s compliance with the General Safety and Performance Requirements and the acceptability of the benefit-risk profile according to the current state-of-the-art.

Administrative details

The last section of the CER includes all the administrative details about the report and who wrote it.

It should include:

Important Considerations

Safety and performance claims must be substantiated

To demonstrate that your device performs as well as, or better than, similar devices in the market, you must provide measurable criteria for your safety and performance objectives, i.e., provide numerical values or other measurable acceptance criteria.

Choose your literature and adverse event databases wisely

To appropriately establish your medical device in the current state-of-the-art, you must choose where and how to search for clinical data. It is not enough to use one scientific literature database and one regulatory database. Not all literature databases share the same focus and searching one might yield vastly different results than searching another.

Your clinical evaluation report must be objective and un-biased

Too many medical device manufacturers become selective during data appraisal and (unconsciously) choose data that suits their narrative. However, your clinical evaluation must be objective and as un-biased as possible to ensure an appropriate evaluation of your device’s benefit-risk profile.