Understanding SDTM EX and EC Domain Annotations

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Understanding SDTM EX and EC Domain Annotations

Understanding SDTM EX and EC Domain Annotations

By StudySAS Team | January 7, 2025

Introduction to SDTM Domains

In clinical data management, the Study Data Tabulation Model (SDTM) is a crucial standard for organizing and formatting data to streamline regulatory submissions. Among its various domains, the EX (Exposure) and EC (Exposure Events) domains play significant roles in documenting participant exposures and related events during a study.

This blog post delves into when and how to annotate these domains, providing detailed examples and best practices based on the SDTM Implementation Guide (IG) Version 3.3.

Understanding the EX Domain

The EX (Exposure) domain is essential for capturing detailed information about the administration of investigational products, concomitant medications, or other exposures participants receive during a clinical study.

When to Annotate the EX Domain

  • Required: If your study involves any form of product or treatment administration.
  • Commonly used in most clinical trials to document dosage, route, frequency, and duration of treatments.
  • Includes data elements such as dosage, route of administration, frequency, duration, and start/end dates of treatment.

Examples When EX Domain Annotations are Required

1. Clinical Trials Involving Investigational Products

Example: A Phase III clinical trial testing the efficacy and safety of a new oncology drug.

  • Data Elements: EXDOSE, EXROUTE, EXSTART, EXEND

2. Studies Involving Concomitant Medications

Example: A clinical trial assessing a new antihypertensive drug where participants continue existing blood pressure medications.

  • Data Elements: EXTRT, EXDOSE, EXSTART, EXEND

Key Considerations for EX Domain Annotation

  • Comprehensive Data Capture: Document all relevant aspects of exposure.
  • Study Protocol Alignment: Ensure annotations align with study protocols.
  • Regulatory Compliance: Adhere to SDTM IG 3.3 and regulatory guidelines.
  • Data Quality and Integrity: Maintain consistency and accuracy in data mapping.
  • Collaboration: Work with clinical operations and data management teams.

Understanding the EC Domain

The EC (Exposure Events) domain is designed to capture specific events or deviations related to participant exposures. These can include missed doses, dose modifications, discontinuations, or any deviations from the prescribed exposure protocol.

When is EC Domain Annotation Required?

  • Mandatory:
    • Deviation from exposure protocol, such as missed doses or dose modifications.
    • Dose adjustments based on participant tolerance, efficacy, or safety concerns.
    • Temporary interruptions due to adverse reactions or concurrent medical conditions.
  • Study Design:
    • Studies with detailed monitoring of exposure compliance.
    • Trials involving complex exposure regimens like combination therapies.
    • Studies where exposure deviations significantly impact participant safety or study integrity.

When is EC Domain Annotation Beneficial?

  • Enhanced Data Transparency: Provides a complete picture of participant exposure and deviations.
  • Improved Regulatory Compliance: Facilitates smoother regulatory audits and reviews.
  • Better Risk Management: Helps in early detection of safety signals related to exposure deviations.
  • Data Integration: Enhances interoperability by linking with other SDTM domains.

Examples and Scenarios for EC Domain Annotation

1. Clinical Trials with Dose Escalation Protocols

Example: A Phase I oncology trial determining the maximum tolerated dose (MTD) of a new chemotherapy agent.

  • Data Elements: ECMOD, ECRPT

2. Studies Monitoring Treatment Adherence

Example: A study assessing the efficacy of a daily oral antihypertensive medication.

  • Data Elements: ECSEQ, ECLINKID

Best Practices for EC Domain Annotation

  • Comprehensive Mapping: Identify and map all potential exposure events from CRFs to EC domain.
  • Clear Documentation: Document the rationale for each exposure event annotation.
  • Collaboration: Work with cross-functional teams to ensure accurate annotation.
  • Standardized Coding: Use controlled terminologies like MedDRA for reasons.
  • Utilize Automation: Employ tools for automated mapping and validation to reduce errors.

When to Use EC Domain Without EX Domain

While the **EC (Exposure Events)** domain is typically used in conjunction with the **EX (Exposure)** domain, there are specific scenarios where EC annotations might be included without corresponding EX annotations on the **annotated Case Report Form (aCRF)**.

Scenarios for EC Domain Without EX Domain

1. Studies Utilizing External or Predefined Exposure Data

Example: A retrospective observational study assessing exposure to environmental pollutants where exposure data is sourced from external databases.

  • Why EC Only: Exposures are predefined and documented externally; the study focuses on tracking related events.
  • Data Elements: ECSEQ, ECSTDY, ECRPT, ECMOD

2. Protocol Deviations Without Specific Exposure Data

Example: A clinical trial where site closures or supply interruptions affect treatment administration but do not alter exposure details.

  • Why EC Only: Focus on documenting protocol deviations impacting exposure without changing the exposure data.
  • Data Elements: ECSEQ, ECSTDY, ECRPT, ECMOD

3. High-Level Exposure Event Tracking in Specific Study Designs

Example: A public health study monitoring major exposure-related incidents like widespread environmental changes.

  • Why EC Only: Records high-level exposure events without individual exposure metrics.
  • Data Elements: ECSEQ, ECSTDY, ECRPT, ECMOD

Key Considerations and Best Practices

  • Regulatory Compliance: Ensure alignment with SDTM IG 3.3 and consult regulatory authorities if deviating from standard practices.
  • Clear Documentation: Justify the exclusion of EX annotations and provide detailed metadata.
  • Data Integrity: Maintain consistent and meaningful EC records even without EX annotations.
  • Collaboration: Engage with all relevant teams to ensure a shared understanding and accurate implementation.
  • Review and Validation: Implement robust validation processes to ensure accuracy and compliance.

Conclusion

Annotating the EX (Exposure) and EC (Exposure Events) domains is pivotal for comprehensive and compliant clinical data management. While the EX domain is generally essential for documenting participant exposures, the EC domain provides additional depth by capturing related events and deviations. Understanding when and how to use these domains, especially the specific cases where EC can be used without EX, ensures data integrity, regulatory compliance, and facilitates robust data analysis.

For more detailed guidelines, always refer to the CDISC SDTM Implementation Guide, Version 3.3 and consult with regulatory bodies as needed.

© 2025 StudySAS. All rights reserved.

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