MEDDEV 2.7.1 Rev. 4 remains the most important technical guidance document for conducting literature searches within the European medical device regulatory framework. Although MEDDEV documents were originally aligned with the former Medical Device Directive (MDD) and Active Implantable Medical Device Directive (AIMDD), they continue to serve as key reference documents for manufacturers, notified bodies, and regulators.

While MEDDEV guidance is not legally binding, it provides practical and widely accepted direction on best practices throughout the conformity assessment process. At present, the Medical Device Coordination Group (MDCG) has not issued detailed guidance specifically describing how literature searches should be conducted. As a result, MEDDEV 2.7.1 Rev. 4 remains the primary source of general guidance on literature search and literature review protocols.

The guidance outlines how literature searches and reviews should be used to identify relevant information on:

  • The medical device under evaluation

  • Equivalent devices

  • The current state of the art, including alternative examination and treatment methods

This information is essential for demonstrating equivalence, safety, and regulatory compliance.

As part of the transition from the MDD to the Medical Device Regulation (MDR), MDCG guidance documents are gradually replacing MEDDEV documents and reflect the latest regulatory thinking of the European Commission. Nevertheless, until more detailed MDCG guidance on literature search methodology becomes available, MEDDEV 2.7.1 Rev. 4 continues to play a central role in clinical evaluation activities.

Key Elements of Literature Search Documentation

The most important requirements for documenting a literature search are described in Annex V of MEDDEV 2.7.1 Rev. 4. In particular, the guidance focuses on the following elements:

  • search categories (e.g. medical device–specific searches or state-of-the-art searches related to the clinical condition)

  • scope of the search strategy

  • search and review methods

  • documentation of the literature search

Introduction to Clinical Evaluation

Clinical evaluation is a cornerstone of the regulatory process for medical devices, serving as the foundation for demonstrating both safety and clinical performance. For medical device manufacturers, conducting a robust clinical evaluation is not only a regulatory requirement but also a critical step in ensuring that their devices deliver the intended benefits to patients while minimizing risks.

At the heart of this process is the clinical evaluation report (CER), a comprehensive document that summarizes the assessment of clinical data and provides a clear justification for the safety and performance of the device. The CER is essential for both initial CE marking and ongoing CE certification, as it demonstrates that sufficient clinical evidence supports the device’s intended use and compliance with relevant regulations.

The European Commission, through MEDDEV guidance documents such as MEDDEV 2.7.1 Rev. 4, has established a common approach to clinical evaluation. These guidelines outline the general principles for identifying, appraising, and analyzing clinical data—whether sourced from clinical investigations, literature reviews, or data on equivalent or similar devices. The process is systematic and ongoing, requiring manufacturers to continually evaluate new data and update their CERs to reflect the current state of knowledge and market experience.

Notified bodies play a pivotal role in conformity assessment procedures, relying on the CER and supporting documentation to verify that medical devices meet the stringent requirements for safety and performance. As the regulatory landscape evolves, MDCG guidance documents are supplementing and, in some cases, replacing MEDDEV documents, providing further clarity on clinical performance, data assessment, and the demonstration of sufficient clinical evidence.

Manufacturers must recognize that clinical evaluation is not a one-time event but a continuous process. The frequency of CER updates depends on factors such as the device’s risk classification, market feedback, design modifications, and the emergence of new clinical data. Regularly updating the clinical evaluation report ensures ongoing compliance, supports CE certification, and ultimately safeguards patient safety.

In summary, clinical evaluation is a vital process for medical device manufacturers, underpinning the demonstration of safety, performance, and regulatory compliance. By following the guidelines set out in MEDDEV 2.7.1 Rev. 4 and related documents, manufacturers can ensure that their devices meet the expectations of notified bodies and the European Commission, maintain market access, and deliver meaningful benefits to patients.

An important amendment in MEDDEV 2.7.1:

An important amendment introduced in MEDDEV 2.7.1 Rev. 4 is the requirement for a Europe-centric literature search. This emphasizes the identification of European clinical data, which is not always comprehensively captured in PubMed.

Prior to this amendment, PubMed was often used as the sole database for literature searches due to its broad coverage and access to high-impact scientific publications. In many cases, this approach was considered sufficient and was accepted by notified bodies.

However, MEDDEV 2.7.1 Rev. 4 highlights important limitations of relying exclusively on PubMed. Studies reporting negative results, post-market user experience, or region-specific clinical outcomes may be less likely to be published in high-impact international journals and therefore may not be adequately represented in PubMed. As a result, manufacturers are expected to extend their searches beyond a single database.

To support a Europe-centric approach, MEDDEV 2.7.1 Rev. 4 recommends the use of European databases such as Embase. Embase provides broader European journal coverage and improved access to regionally relevant clinical data, making it particularly suitable for regulatory literature searches conducted under the MDR.

Although PubMed allows free searching and registration, access to full-text articles is not always free of charge. For this reason, PubMed should be considered a supplementary resource, rather than a standalone solution, within a compliant Europe-centric literature search strategy.

Essential Objectives of the literature search:

In accordance with MEDDEV 2.7.1 Rev. 4, the literature search must address at least two essential objectives:

  • Demonstrate the state of the art relevant to the medical device under clinical evaluation, enabling comparison with current clinical practice, existing technologies, and alternative examination or treatment methods.

  • Demonstrate the clinical safety, performance, and clinical benefit of the medical device under evaluation in order to support claims of equivalence. This requires relevant statements and clinical evidence relating to the device itself and to equivalent devices where applicable.

The clinical evaluation report must summarize the evaluation of relevant clinical data and its output.

Documenting the objectives of the literature search:

In accordance with the guideline, the objectives of the literature search(es) must be documented. These objectives could range from:

  • Providing clinical data on the medical device under evaluation

  • Identifying important data for the risk management process with a focus on patient population and existing interventions

  • Providing information for the clinical evaluation of the benefit/risk profile

  • Giving an overview of the current safety specifications

  • Enabling comparison of possible side effects

  • Providing information on benchmark medical devices.

When documenting these objectives, it is essential to respect the intended use of the device, particularly when assessing its safety and performance in compliance with MEDDEV 2.7.1 Rev. 4 standards.

Depending on the objective different search terms are used.

Additionally, the clinical evaluation and its documentation must be updated throughout the lifecycle of the device according to EU MDR.

A methodical approach is essential for the literature search process.

The sequence of literature search and selection

Beginning with a suitable research question, it is crucial to select appropriate databases and formulate promising search terms to effectively perform and carry out the literature search and evaluation. In addition to databases, bibliographies, targeted manual searches, or catalogues from the manufacturers may also contain informative publications. It is important that search methods, search terms, strategies, and particularized results be documented in detail in the final report.

Despite the new EU MDR regulations, the general principles of carrying out a clinical evaluation have not changed.

How should I identify relevant publications?

Relevant publications should be identified through a structured and systematic screening process.

An initial database search should be performed to identify potentially relevant publications based on titles and abstracts. Publications that are clearly not relevant can be excluded at this stage. The remaining publications should then be assessed using full-text review to determine their suitability for inclusion in the literature review.

Criteria for relevance should include whether the publication provides:

  • appropriate background or contextual information

  • meaningful evidence relating to clinical safety, performance, or clinical benefit

  • data relevant to the intended use of the medical device

Relevance must always be assessed in relation to the intended use of the device, ensuring that the conclusions drawn from the clinical evaluation are appropriate for demonstrating safety and performance.

To support a structured literature search, MEDDEV 2.7.1 Rev. 4 recommends the use of the PICO framework(Patient/Population, Intervention, Comparison, Outcome). This approach, widely used in evidence-based medicine, helps define focused search criteria and is particularly useful when identifying literature related to the state of the art.

It is important to note that, despite the introduction of the EU MDR, the general principles of conducting a clinical evaluation remain unchanged.

Quick Tips for an Effective Literature Search:

Use (Boolean) operators

Boolean operators are logical connectors (AND, OR, NOT) used in literature searches to combine or exclude search terms and control the scope and relevance of search results. Boolean operators help refine and control the scope of a literature search. They can be used to narrow results by increasing specificity or to broaden results when insufficient literature is retrieved.

The most commonly used Boolean operators are:

  • AND
    Combines search terms and retrieves results that contain all specified terms.

  • OR
    Broadens the search by retrieving results that contain any of the specified terms.

  • NOT
    Excludes results that contain a specific term, helping to eliminate irrelevant publications.

Additional search tools can further improve the relevance and precision of search results:

  • Quotation marks (” “)
    Force the database to search for terms in the exact wording and order specified.

  • Round brackets ( )
    Group search terms and define how Boolean operators are applied within a search strategy.

Because different databases may apply Boolean operators and symbols differently, users should consult the relevant database guidance to ensure correct usage. The presence or absence of brackets can significantly affect how search phrases are interpreted and, consequently, the search results obtained.

Exclude unrelated publications at an early stage to save time

Since a literature search often returns several hundred publications, it is important to funnel down the long list and exclude the non – relevant publications at the outset to save precious time. Based on the abstract, if publications do not relate to the state of the art or the medical device under clinical, they should be excluded from the literature review process.

Standard Mistakes during Literature Search

Several recurring issues are frequently identified during regulatory review of literature searches and clinical evaluation documentation.

Lack of a Defined Literature Search Methodology

One of the most common mistakes is the absence of a clearly defined and documented literature search and review methodology. Literature search protocols that do not specify selected keywords, inclusion and exclusion criteria, and suitability criteria are difficult to reproduce and evaluate. A lack of methodological transparency can significantly compromise the assessment of the literature search and clinical evaluation. Such deficiencies may jeopardize initial CE marking, as a robust and reproducible methodology is essential for demonstrating regulatory compliance.

Use of Non-Equivalent Device Literature

Another common error is the use of literature from medical devices that do not demonstrate equivalence to the device under clinical evaluation. Both MEDDEV guidance documents and the MDR explicitly state that only literature relating to equivalent medical devices may be used to generate clinical evidence for the device under evaluation.

While literature from non-equivalent devices may be referenced for background information within the clinical evaluation report, it cannot be used as evidence of clinical safety or performance. In addition, manufacturers must have appropriate contracts in place to access clinical and technical data for any equivalent competitor device, as required by MEDDEV 2.7.1 Rev. 4.

Failure to Incorporate Post-Market Surveillance Data

For CE-marked medical devices, companies sometimes fail to adequately consider post-market surveillance (PMS) data. Manufacturers are required to proactively collect and review PMS data from their own devices as well as from equivalent or competing devices. Supplementary literature searches and reviews of incident databases, such as MAUDE, can help ensure that PMS data remains current and comprehensive.

Incomplete Documentation of the Literature Search

MDCG 2020-13 explicitly requires notified bodies to review literature search documentation as part of conformity assessment activities. Incomplete documentation may therefore result in non-conformities, leading to additional queries or audit findings.
To avoid this, manufacturers should ensure that literature search protocols include comprehensive metadata, such as:

  • search terms used

  • databases searched

  • inclusion and exclusion criteria

  • management of duplicate publications

  • literature review procedures and documentation

  • evaluation of search methods

Summary

MEDDEV 2.7.1 Rev. 4 remains a key technical guidance document for conducting literature searches and supporting clinical evaluation activities under the EU MDR. While not legally binding, it provides practical and widely accepted direction that helps manufacturers demonstrate compliance throughout the conformity assessment process.

The principles and recommendations outlined in this article support a structured, reproducible, and regulatory sound literature search. Key considerations include defining clear objectives, using appropriate search strategies and databases, controlling the scope and specificity of search results through tools such as Boolean operators, and excluding irrelevant publications at an early stage of the review process.

In addition to demonstrating the state of the art, manufacturers must ensure that clinical evidence relating to equivalent medical devices is appropriately evaluated. In practice, this typically requires at least two complementary literature searches—one addressing the state of the art and another focusing on the medical device under evaluation or equivalent devices.

By following the guidance in MEDDEV 2.7.1 Rev. 4, manufacturers can strengthen their clinical evaluation documentation, reduce the risk of non-conformities, and support successful CE certification and ongoing market access.

Frequently Asked Questions

Who is MEDDEV 2.7 1 revision 4 for?

MEDDEV 2.7.1 Rev. 4 is intended for manufacturers, regulatory professionals, and other stakeholders involved in the clinical evaluation of medical devices.

Are there any upcoming updates for MEDDEV 2.7 1 revision 4?

At present, there are no officially scheduled updates. However, there are indications that further guidance may be developed to better align existing recommendations with the requirements of the EU Medical Device Regulation (MDR).

Does MEDDEV 2.7 1 revision 4 also described the Clinical Evaluation Report?

Yes. MEDDEV 2.7.1 Rev. 4 includes guidance on the preparation of the Clinical Evaluation Report, including a proposed table of contents and illustrative content examples.

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