WHODrug Global contains codes for a wide range of drugs, and is available in different scopes such as WHODrug Enhanced and WHODrug Herbal, which enable coding of everything from conventional medicines to herbal treatments. WHODrug Global is a drug reference dictionary that was first created in 1968, and uses the Anatomical Therapeutic Chemicalclassification system to classify drugs. MedDRA has undergone multiple revisions since it first began, and is updated every six months. MedDRA is maintained, distributed, and supported by the MSSO (MedDRA Maintenance and Support Services Organization) and the JMO (Japanese Maintenance Organization). This dictionary was originally based on a set of terminology used in the United Kingdom in the 1990s, and the ICH (the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) spearheaded the effort to bring this standard set of medical coding terms into use worldwide. gastrointestinal disorders) down to lowest level terms (e.g. The MedDRA dictionary is based on a five-tier hierarchical structure (Figure 1) that goes from system organ class (e.g.
MedDRA, the Medical Dictionary for Regulatory Activities, is a multilingual dictionary of standard terminology that is used to code medical events in humans, including patients’ medical histories and adverse events. Two of the most widely used medical dictionaries in clinical trial systems are MedDRA and WHODrug Global. Coding means taking the free text entered into electronic case report files (eCRFs) and mapping it to one or more entries in a medical dictionary. Using medical dictionaries to code clinical trial data is a key way to ensure that your clinical trial records and databases are easy to interpret and analyze.