About Clinical Coding


The Vault Coder application allows you to ensure pharmacovigilance in a clinical study by standardizing clinical data and reveals statistically significant occurrences of adverse events and the use of concomitant medication to prevent or mitigate the adverse events.

Purpose of Clinical Coding

Terms for concomitant medications and adverse events used in clinical study forms may be different because a study may be conducted at multiple sites in different geographical locations where different languages may be used, and because site staff may use non-traditional terms to describe a medication or medical condition. For example, one site may fill out forms using the term Tylenol, while another site may use a generic term for the same medication, Acetaminophen. These variations in terminology must be standardized to allow for statistical analysis of a study. In the example above, the synonyms Tylenol and Acetaminophen would need to be assigned a common code so that they are identified as being the same drug within study forms. Reported adverse events subjects experience from taking a trial drug may also be coded for and standardized.

WHODrug Code Structure

WHODrug codes use the Anatomical Therapeutic Chemical (ATC) classification system, which classifies the drugs based on the system of the body on which they act and their therapeutic properties. ATC codes are built on a hierarchy, ATC1 to ATC4 (as shown in the image below). The first level of the code begins broadly, denoting the system of the body a drug is used to treat, and moves up in specificity to the therapeutic area for the drug.

WHODrug COde Structure

MedDRA Code Structure

The MedDRA dictionary defines medical conditions. MedDRA codes are organized by System Organ Class (SOC). The code begins with the system of the body affected and becomes more specific. The SOC codes are divided into High-Level Group Terms (HLGT), High-Level Terms (HLT), Preferred Terms (PT) and finally into Lowest Level Terms (LLT).

MedDRA Code Structure