This blog includes:
- A breakdown of the MedDRA layered system.
- A quick overview of each term in the hierarchy.
- A visual demonstration for a clear and easy understanding of the entire content.
Table of Contents:
- Introduction
- Understanding MedDRA: A General Overview
- Overview of the Hierarchical System within MedDRA
- Closing Thoughts
- FAQ
Introduction
Hierarchy in structured data involves the precise refinement of information, progressing from a broader scope to a more detailed and specific level.
In the context of MedDRA, hierarchy is a structured classification system divided into five levels, each representing a progressively more specific term as you move from the top level to the bottom.
Understanding MedDRA term
- Objective: is to promote accurate and consistent term selection to facilitate a common understanding of shared data.
- Purpose: Shorter version focusing on general coding principles to promote accurate and consistent use of MedDRA worldwide.
- Developed by a working group of the ICH Management Committee.
- If terms are incorrectly placed, submit a change request to the MSSO.
- If no exact match in MedDRA, use medical judgment to match to an existing term that adequately represents the concept.
The Layered System of MedDRA
The hierarchical structure in MedDRA is as follows:
- System Organ Class (SOC)
- High-Level Group Term (HLGT)
- High-Level Term (HLT)
- Preferred Term (PT)
- Lowest-Level Term (LLT)
1. System Organ Class (SOC)
It is the broadest level of classification, representing medical conditions, symptoms, and adverse events based on the anatomical or physiological system. There 27 major classifications under SOC.
2. High-Level Group Term (HLGT)
A High-Level Group Term (HLGT) is an intermediate secondary level within the MedDRA (Medical Dictionary for Regulatory Activities) hierarchy used for the classification and organization of medical terms related terms within a SOC.
Specifically, it falls between the System Organ Class (SOC) and the High-Level Term (HLT) in the MedDRA hierarchy.
3. High-Level Term (HLT)
In the context of the Medical Dictionary for Regulatory Activities (MedDRA), a High-Level Term (HLT) is at middle order after (HLGT). HLT is be more specific in orders of classification than the upper orders such as SOC and HLGT.
MedDRA serves as an indispensable resource, not only aiding coders but also acting as a lifeline for the entire healthcare ecosystem in terms of ensuring safety.
Unlocking the Power of MedDRA with Drugvigil: Your Path to Becoming an Expert
4. Preferred Term (PT)
In the hierarchy of MedDRA, the Preferred Term (PT) holds significant importance, positioned at the fourth level. Especially when populating E2B formats for pharmacovigilance and regulatory reporting.
Each PT represents a single clinical concept or entity.
5. Lowest-Level Term (LLT)
Selecting the Lowest Level Term (LLT) is a pivotal step in the process, and within LLTs, there can be up to 4 to 5 subcategories. Importantly, when you choose an LLT, it does not alter the hierarchy above it. The LLT should be chosen with utmost precision, guided by the source data information.
For instance, consider the Preferred Term (PT) “Arrhythmia,” which offers four potential LLTs:
- Arrhythmic NOS – Not specified
- Arrhythmia
- Other specified cardiac dysrhythmias
- Dysrhythmias.
When making this selection, it’s essential to pick the LLT that best aligns with the specific source data, ensuring accuracy and consistency in coding and reporting.
Closing Thoughts:
In this blog, we’ve dive into the explanation hierarchical structure of MedDRA, shedding light on its extensive array of available terms and the organisation of classes within it. It’s essential to keep in mind that MedDRA is a dynamic system, subject to periodic updates that may result in fluctuations in the number of terms, either increasing or decreasing.
As we conclude, I’d welcome your input on any additional topics or aspects you believe should be included in this blog.
Feel free to leave your comments and suggestions below.
References:
FAQ:
What is MedDRA?
Is MedDRA primarily a drug coding dictionary?
What are the levels within MedDRA system?
2. High-Level Group Term (HLGT)
3. High-Level Term (HLT)
4. Preferred Term (PT)
5. Lowest-Level Term (LLT)
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