System Organ Class

System Organ Class (SOC) is a hierarchical classification system used in the field of pharmacovigilance and clinical trials to categorize the nature of adverse events reported in the development, testing, and post-marketing surveillance of pharmaceuticals. The SOC system is part of the Medical Dictionary for Regulatory Activities (MedDRA), which is a globally accepted standard for the classification of medical information related to regulatory activities and safety reporting.

Overview

The SOC classification organizes adverse events into groups based on the biological system or organ class that they affect. This system allows for a systematic tracking and analysis of adverse events, facilitating the identification of potential safety signals and trends that may be associated with the use of a particular drug or therapeutic intervention.

Structure

The SOC hierarchy is structured into several levels, with the top level being the system organ class itself. Each SOC is divided into High-Level Group Terms (HLGTs), which are further subdivided into High-Level Terms (HLTs). Below HLTs are Preferred Terms (PTs), which describe specific adverse events. At the lowest level of the hierarchy are the Lowest Level Terms (LLTs), which are synonyms or lexical variants of the PTs.

Common System Organ Classes

Some of the major system organ classes include, but are not limited to:

• Cardiac disorders
• Gastrointestinal disorders
• Nervous system disorders
• Psychiatric disorders
• Respiratory, thoracic and mediastinal disorders
• Skin and subcutaneous tissue disorders

Usage

SOCs are used extensively in the regulatory submission of drugs for approval, in the ongoing monitoring of drug safety post-approval, and in the conduct of clinical trials. They provide a standardized language that facilitates the communication of safety information among healthcare professionals, regulatory authorities, and the pharmaceutical industry.

Advantages

The use of SOCs and the broader MedDRA system offers several advantages:

• Standardization of terminology, which reduces ambiguity in adverse event reporting.
• Facilitation of the global exchange of safety information.
• Ability to track and analyze trends in adverse event reporting over time.

Challenges

Despite its advantages, the use of the SOC system also presents challenges:

• The broad categories of SOCs can sometimes obscure the specific nature of an adverse event.
• The hierarchical structure requires careful navigation to ensure accurate coding of adverse events.

Conclusion

The System Organ Class classification within MedDRA is a critical tool in the field of pharmacovigilance, offering a structured approach to the categorization and analysis of adverse events. Its widespread adoption underscores its value in promoting drug safety and protecting public health.