What Notified Bodies Really Look For In Literature Reviews

Uncovering the evaluation criteria that make or break MDR submissions

A recent insight during an AKRA TEAM webinar revealed a fundamental truth on literature reviews under MDR:

“Literature searches tell me how much you know about your device. And they are probably one of the most important elements of your clinical evaluation that helps me build trust in your review.”

- Diane Legere, Senior Clinical Auditor, DNV

These reviews aren't academic exercises—they're critical assessments that directly feed into risk management and clinical evaluation processes. Yet despite widespread industry awareness of MDR requirements, literature reviews remain a consistent stumbling block in regulatory submissions.

[Download the Guide to Medical Literature Review]

What separates successful submissions from those that face delays or rejections? The answer lies in understanding how notified bodies actually evaluate these documents—not just what they contain, but how they're structured, reasoned, and integrated into broader clinical strategies.

Beyond Compliance: Literature Reviews as Competence Indicators

Notified body reviewers use literature reviews as diagnostic tools to assess manufacturer competence. A methodologically sound review signals strategic planning and technical expertise, while poorly executed reviews suggest weak internal controls and potential safety gaps.

A well-prepared review signals diligence, strategic planning, and technical knowledge. Conversely, a poorly executed literature review suggests superficial effort, weak internal controls, and potential gaps in safety and performance justification.

This evaluation extends beyond content verification. Reviewers examine whether manufacturers have critically engaged with evidence, not merely compiled it. They expect transparency in search methods, logical organization, and clear alignment between literature findings and clinical claims—indicators that the evidence generation process is robust and reliable.

The Methodology Mandate: Structure That Builds Confidence 

The first area under reviewer scrutiny is methodology. Literature reviews lacking clear structure or documented search logic raise immediate red flags.

Reviewers look for a clearly stated plan (typically in the form of a Literature Search Plan, or LSP) that outlines where, how, and why literature was selected.

Essential elements include appropriate database selection (PubMed, Embase, and domain-specific sources), precise documentation of search strategies with full Boolean operators and filters, and systematic screening processes.

The screening documentation must show article numbers at each stage—identified, deduplicated, excluded—with logical, consistently applied exclusion criteria.

A flowchart or PRISMA-style diagram is often used to illustrate this process and is considered good practice.

Quality appraisal represents another core expectation. Reviewers demand evidence that included studies underwent systematic assessment for methodological rigor, bias, and relevance. Quality ratings or standardized scoring systems demonstrate that reviews evaluate evidence weight, not just evidence volume.

Most critically, reviewers expect synthesis—connecting literature findings to specific device claims.

Merely listing or summarizing study outcomes does not meet the standard. Reviewers want to see interpretation, comparison, and relevance.

Fatal Flaws: Deficiencies That Derail Submissions

Despite increasing guidance availability, avoidable deficiencies continue undermining submissions. The most frequent failure is inadequate synthesis. Reviews often present detailed data tables and lengthy study summaries without explaining how findings support device performance or safety profiles. 

Without a narrative that ties evidence back to clinical claims, the review remains incomplete.

Missing critical appraisal represents another common weakness. When studies are included without quality assessment, reviewers question whether conclusions rest on strong or biased evidence. Even comprehensive reviews fall short if they fail to distinguish between high-quality clinical trials and lower-quality observational data.

Search strategy problems also trigger reviewer concerns. Overly broad terms generate unmanageable irrelevant volumes, while overly narrow searches potentially exclude key references. Incomplete search logic documentation compounds these issues, as does failure to update searches within regulatory timelines.

Template misuse creates additional problems. While templates ensure consistency, reviewers quickly identify inadequately customized content. Unchanged boilerplate language suggests insufficient diligence. 

Templates should guide, not replace, expert analysis.

Finally, insufficient comparative analysis weakens benefit-risk assessments. Reviews lacking detail about alternative treatments or similar technologies leave questions about device positioning unanswered—critical information for regulators assessing whether devices offer favorable clinical profiles versus existing solutions.

Post-Market Reality: Ongoing Literature Monitoring

Literature review obligations extend beyond initial certification. Under MDR, manufacturers must monitor literature continuously through PMS and PMCF systems. Reviewers examine whether processes enable repeatability and quality system integration.

Reviewers want to see evidence that literature reviews are conducted at appropriate intervals—at least annually, in most cases—and that they are integrated with signal detection and risk management processes.

Updates must maintain methodological consistency with original reviews. Significant changes in appraisal criteria, search terms, or inclusion rules undermine evaluation continuity confidence.

Organizations are expected to maintain the same level of rigor in updates as in the initial review.

Quality Over Quantity: The Reviewer Mindset

Volume doesn't equate to quality in reviewer assessment. Extensive article lists, hundreds of appendix pages, or exhaustive data tables aren't inherently persuasive.

A lean but well-reasoned review often carries more weight than a disorganized compendium of references.

This principle particularly applies to legacy devices or low-risk products with limited literature. Reviewers prioritize realistic, transparent analysis over quantity. Where gaps exist, they want clear plans for addressing them through clinical studies, PMCF activities, or post-market monitoring.

The Strategic Imperative

As MDR enforcement intensifies and notified body scrutiny increases, literature reviews have become pivotal demonstrations of clinical safety and performance. Success requires understanding reviewer evaluation methods and proactively addressing common weaknesses.

By understanding how literature reviews are evaluated—and by proactively addressing common weaknesses—manufacturers can strengthen their submissions and improve review outcomes.

Well-executed literature reviews transcend compliance requirements. They reflect clinical strategy quality and build product confidence—the foundation for safe, effective medical device performance that benefits manufacturers and regulators alike.