Managing MedDRA Version Updates in Clinical Trials

Why MedDRA Versions Are Updated

The Medical Dictionary for Regulatory Activities (MedDRA) is updated twice a year—typically in March and September. These updates ensure that the dictionary evolves with medical science, incorporating new terms, restructuring hierarchies, and refining definitions. For sponsors, CROs, and regulators, version updates improve data accuracy, harmonize coding, and support signal detection across therapeutic areas.

Updates may include new Preferred Terms (PTs), modifications to System Organ Classes (SOCs), or reclassification of existing terms. For example, emerging conditions such as “COVID-19 pneumonia” were added in recent versions. Sponsors must adopt these updates in a timely manner to remain compliant with regulatory expectations. Agencies such as the FDA, EMA, and PMDA require that safety data submissions specify the MedDRA version used for coding.

Failure to manage version updates can result in inconsistent datasets, delayed submissions, and inspection findings. Thus, implementing structured processes for MedDRA updates is essential for regulatory compliance and pharmacovigilance.

Impact of Version Updates on Clinical Trials

Each MedDRA update can affect ongoing trials in several ways:

• New terms: Coders gain access to updated LLTs and PTs reflecting current medical knowledge.
• Retired terms: Certain LLTs may be deprecated, requiring recoding of existing events.
• Hierarchical shifts: PTs may be reassigned to different SOCs, changing how aggregate analyses are performed.
• Cross-study comparisons: Trials coded with different versions may produce inconsistent datasets unless reconciled.

For example, if “Myocardial infarction type 2” is added as a PT in a new version, coders must reassign prior cases coded under general “Myocardial infarction” PTs to ensure consistency in safety analyses.

Version changes may also impact DSURs, PSURs, and aggregate reports. Regulators often question whether sponsors have adequately managed version transitions when inconsistencies appear in safety datasets.

Case Example: MedDRA Version Transition in an Oncology Trial

Consider a Phase III oncology trial using MedDRA version 23.0. Midway through the trial, version 24.0 introduces new PTs for immune-related adverse events, including “Immune checkpoint inhibitor colitis.” The sponsor must:

1. Update the safety database to MedDRA v24.0.
2. Recode historical events from general terms like “Colitis” to the new PT where appropriate.
3. Train coders on the new version and updated coding conventions.
4. Document the reconciliation process in the Trial Master File (TMF).

This case illustrates how timely adoption of new versions ensures accurate pharmacovigilance and regulatory compliance, particularly in emerging therapeutic areas.

Regulatory Expectations on MedDRA Version Management

Regulatory agencies expect sponsors to demonstrate traceability and consistency in handling MedDRA updates. Common expectations include:

• Version documentation: Submissions must clearly state the MedDRA version used for coding.
• Transition management: Sponsors should document how and when version updates were implemented.
• Reconciliation: Safety datasets must be reconciled to avoid inconsistencies across versions.
• Training: Coders must be trained on new terms, structures, and conventions introduced in each update.
• Audit readiness: Regulators may review version transition logs during inspections.

Inspection findings often highlight failures in version management, such as continued use of outdated versions or lack of documentation on recoding decisions. For global compliance, sponsors should align coding practices across all regions, ensuring FDA, EMA, and CDSCO submissions use harmonized MedDRA versions.

Best Practices for Handling Version Updates

To effectively manage MedDRA updates, sponsors should adopt the following practices:

• Establish SOPs: Define clear procedures for adopting new MedDRA versions.
• Plan updates: Implement updates immediately after March and September releases.
• Reconcile datasets: Perform systematic recoding of historical cases impacted by new or retired terms.
• Train coders: Provide refresher training with examples of new terms and hierarchical changes.
• Audit processes: Maintain version control logs, reconciliation records, and coding decision documentation.

For instance, a sponsor may maintain a version reconciliation log that documents all PTs changed during an upgrade, along with rationale for recoding decisions. Such logs serve as valuable inspection artifacts.

Challenges in Managing Updates

Despite best practices, challenges remain:

• Resource burden: Updating databases and training coders requires time and staff.
• Cross-study consistency: Reconciling coding across multiple ongoing trials can be complex.
• Regulatory timelines: Version updates often coincide with critical submission deadlines.
• Automation risks: Auto-recoding features may misclassify terms without manual review.

These challenges highlight the importance of proactive planning, sponsor oversight, and hybrid manual/automated reconciliation processes.

External Resources and References

Coders and safety professionals should leverage external resources to stay aligned with regulatory expectations. The ISRCTN Registry often references MedDRA coding standards in trial protocols, demonstrating global alignment on terminology usage.

Key Takeaways

Handling MedDRA version updates is a critical pharmacovigilance function. Clinical teams must:

• Adopt new MedDRA versions promptly after release.
• Reconcile coding across trials to maintain consistency.
• Document transitions, rationale, and recoding decisions in audit-ready logs.
• Train coders on new terms and hierarchical changes.
• Maintain inspection readiness by aligning global submissions to the same version.

By managing MedDRA updates systematically, sponsors ensure accurate safety data, regulatory compliance, and reliable pharmacovigilance across global clinical development programs.

How to Code Ambiguous Verbiage in MedDRA for Clinical Trials

Introduction to Ambiguous Verbiage in Adverse Event Reporting

In clinical trials, adverse events (AEs) are initially reported by investigators in verbatim language, often reflecting patient statements or clinical notes. These terms are not always precise. Ambiguous expressions such as “feeling unwell,” “stomach upset,” or “heart problem” pose significant challenges during MedDRA coding. Unlike clear terms like “myocardial infarction” or “rash,” ambiguous terms require coder interpretation, which increases the risk of misclassification and regulatory non-compliance.

Regulators including the FDA, EMA, and CDSCO emphasize that accurate and consistent MedDRA coding is critical for pharmacovigilance and safety signal detection. Incorrect coding due to ambiguity can distort safety analyses and undermine the validity of DSURs, PSURs, and IND safety reports. To address this challenge, sponsors must implement SOPs, coding conventions, and training programs that guide coders in interpreting and coding ambiguous terms consistently.

Examples of Ambiguous Verbiage in Clinical Trials

Ambiguity often arises because investigators record patient experiences in lay language. Below are common examples and potential MedDRA interpretations:

These examples highlight the complexity of coding ambiguous terms. Without adequate conventions, coders may apply different PTs across trials, leading to inconsistent datasets.

Risks of Incorrect Coding Due to Ambiguity

Ambiguous coding errors can have serious consequences:

• Signal distortion: Misclassification of AEs can mask or exaggerate safety signals.
• Regulatory findings: Inspectors often flag inconsistencies in coding of ambiguous terms.
• Data fragmentation: Similar events coded differently across trials prevent accurate pooling of safety data.
• Audit deficiencies: Lack of documentation on coding decisions may be cited as a GCP non-compliance.

For instance, if “fainting” is coded as “Loss of consciousness” in one trial and “Syncope” in another, regulators may question the reliability of cross-study safety analyses. Consistency is therefore paramount in ambiguous coding cases.

Strategies for Handling Ambiguous Verbiage

Sponsors and CROs can manage ambiguity by applying structured strategies:

• Request clarification: Where possible, query the investigator for more detail before final coding.
• Use general PTs: When specifics are lacking, coders may assign broader PTs such as “Malaise.”
• Follow SOP conventions: Coding conventions should define how ambiguous terms are consistently coded.
• Flag for review: Ambiguous cases should undergo medical review by safety physicians.
• Document rationale: Coders should record the reasoning for selected PTs in audit trails.

For example, a sponsor SOP may state: “All reports of ‘feeling unwell’ should be coded as PT ‘Malaise’ unless additional clinical details are available.” Such conventions reduce variability and inspection risks.

Regulatory Expectations and Inspections

Regulators expect coders to demonstrate traceability in coding decisions for ambiguous terms. Common inspection findings include:

• Inconsistent PT selection across similar events.
• Failure to query investigators for clarification.
• Lack of documentation explaining coding rationale.
• Use of auto-coding without manual review of ambiguous terms.

To meet expectations, sponsors should establish coding conventions, maintain training records, and conduct routine audits. Inspection readiness requires evidence that ambiguous coding decisions were consistent, justified, and traceable. Public registries such as the NIHR Be Part of Research platform highlight the importance of standardized terminology for global safety data consistency.

Best Practices for Coders

Best practices for handling ambiguous terms include:

• Maintain detailed coding conventions with common ambiguous terms and assigned PTs.
• Provide refresher training to coders on how to handle vague or incomplete terms.
• Ensure coders escalate complex cases to medical safety officers.
• Review ambiguous terms in coding quality audits.
• Update conventions after each MedDRA version release.

These practices ensure that ambiguous terms are consistently coded and that datasets remain reliable across trials and submissions.

Key Takeaways

Coding ambiguous terms in MedDRA requires coders to balance accuracy, consistency, and regulatory compliance. To achieve this, clinical teams must:

• Recognize common sources of ambiguity in investigator-reported terms.
• Develop SOPs and conventions for standardizing ambiguous coding decisions.
• Document rationale and maintain audit trails for inspection readiness.
• Train coders and escalate complex cases to medical experts.
• Perform quality reviews to ensure consistency across trials.

By following structured strategies, sponsors and CROs can minimize the risks of misclassification, ensure reliable pharmacovigilance data, and meet global regulatory expectations.