What is the four-eyes principle in IFU review?

The four-eyes principle means that every translated IFU is reviewed by at least two independent persons before release. Typically, a qualified specialist translator reviews linguistic quality while a subject matter expert (e.g., Regulatory Affairs Specialist or product specialist) reviews content and regulatory correctness. This principle is a central component of quality assurance under ISO 13485.

Who should be involved in an IFU review?

A complete IFU review workflow typically involves the following roles: the specialist translator (linguistic review), an in-country reviewer (native-language review in the target market), a Regulatory Affairs Specialist (regulatory compliance), a product expert (technical accuracy), and a final release authority. Depending on the risk class of the device, individual steps may be consolidated or expanded.

How do I document the IFU review process for audits?

Document every review step with date, reviewer name, role, reviewed version, and result (approved, changes required, rejected). Use an electronic system with audit trail functionality that traceably logs changes and approvals. manualworks provides integrated review documentation that automatically records all steps and makes them available for audits.

Workflow

The Perfect IFU Review Workflow

Implementing Structured Quality Assurance for Translated Instructions for Use

6 min read

Why a Structured Review Workflow Is Indispensable

The quality of a translated IFU is not determined solely during translation — it is determined during review. Even experienced specialist translators make mistakes, and even the best translation memory cannot always correctly capture context-dependent nuances. A structured review workflow ensures that linguistic, technical, and regulatory errors are identified and corrected before the IFU reaches the market.

The MDR 2017/745 and the harmonized standard ISO 13485 require manufacturers to maintain a documented quality management system covering all processes that affect product safety. The translation and review of instructions for use unquestionably falls within this scope. Notified Bodies are increasingly verifying whether manufacturers have established a traceable review process for their IFU translations.

The Roles in the Review Process

An effective IFU review workflow defines clear roles and responsibilities. Each role contributes a specific perspective that is indispensable for the overall quality of the translated IFU.

The Specialist Translator

The specialist translator produces the initial translation and is responsible for linguistic quality. They must not only master the target language but also possess sound knowledge of medical device terminology. Ideally, they use a translation memory system that ensures consistent terminology and flags deviations from established glossary entries.

The In-Country Reviewer

The in-country reviewer is a native speaker in the target market who reviews the translation for natural language usage, local conventions, and cultural appropriateness. This role is particularly important for markets where regional language variants exist — such as Portuguese for Portugal vs. Brazil, or French for France vs. Belgium/Switzerland.

The Regulatory Affairs Specialist

The RA Specialist reviews the translation not for linguistic quality but for regulatory compliance. They ensure that warnings are correctly formulated, that symbols are used in accordance with ISO 15223-1, and that country-specific regulatory requirements are met. This review is independent of the linguistic review and should be conducted even when linguistic quality has already been rated as good.

The Product Expert

For complex medical devices, involving a product expert who confirms the technical accuracy of the translation is advisable. This expert knows the product in detail and can assess whether a formulation, while linguistically correct, is technically misleading.

The Four-Eyes Principle in Practice

The four-eyes principle is a minimum standard regarded as best practice in medical technology. It means that every translation is reviewed by at least one additional person who was not involved in its creation. For products of higher risk classes, an extended six-eyes principle involving three independent reviewers is recommended.

Reviewer independence is crucial: the reviewer must not be the translator themselves, and ideally should have no personal or business relationship with the translator that could compromise their objectivity. In practice, this means that internal translations should be reviewed by external reviewers and vice versa.

Defining Review Criteria

Every reviewer needs clear review criteria. Create checklists covering the specific aspects each role should examine. Linguistic reviewers check grammar, spelling, terminology consistency, and natural language usage. Regulatory reviewers verify compliance with applicable standards and regulations. Technical reviewers assess technical accuracy and comprehensibility.

The Sign-Off Process

The sign-off process is the formal release of a translated IFU for use. It must be documented and traceable. An effective sign-off process includes the following elements: unique identification of the reviewed version (document number, revision number, language), confirmation from each reviewer that the review is complete, a list of all errors found and resolved, and formal release by the release authority with date and signature.

Electronic sign-off systems offer significant advantages over paper-based processes: they are faster, more tamper-proof, and enable centralized archiving of the entire audit trail. manualworks integrates the sign-off process directly into the translation workflow, allowing all participants to view the current status of each language version in real time.

Common Mistakes in the Review Workflow

Even with a defined process, weaknesses frequently creep in. The most common include: unclear responsibilities (no one feels accountable), missing deadlines (reviews delay the overall process), superficial reviews (reviewers confirm without careful examination), and missing escalation paths (what happens when the reviewer and translator disagree?).

Avoid these pitfalls by establishing clear responsibilities, binding deadlines, and defined escalation routes. Train your reviewers regularly and measure review quality against objective criteria.

Conclusion

A perfect IFU review workflow is not a luxury — it is a regulatory necessity and a guarantor of patient safety. Invest in clear role assignments, defined review criteria, and a documented sign-off process. The time you invest in a structured review will be saved many times over during audits, approval procedures, and the avoidance of corrective actions.