MedDRA FAQ

MedDRA - the Medical Dictionary for Regulatory Activities - is a medical terminology used to classify adverse event information associated with the use of biopharmaceuticals and other medical products (e.g., medical devices and vaccines). Coding these data to a standard set of MedDRA terms allows health authorities and the biopharmaceutical industry to more readily exchange and analyze data related to the safe use of medical products.

MedDRA, developed by the International Conference on Harmonisation (ICH), is continuously enhanced to meet the evolving needs of its users, who include regulators and industry worldwide. ICH has created a governance structure to nurture and protect the integrity of MedDRA. The ICH MedDRA Management Board, appointed by the ICH Steering Committee, has overall responsibility for the direction of MedDRA, and oversees all the activities of the MedDRA Maintenance and Support Services Organization.

MedDRA is used to report adverse event data from clinical trials, as well as post-marketing and pharmacovigilance.

The following are guidelines for the use of MedDRA in publications (e.g., journal articles, web based articles, blogs, etc.):

MedDRA text terms may be used in examples, but the examples need to be limited in size (less than 1000 terms).

It should be cited in the article that MedDRA® the Medical Dictionary for Regulatory Activities terminology is the international medical terminology developed under the auspices of the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH).

The following acknowledgement statement needs to appear in all articles referencing MedDRA: MedDRA® trademark is owned by IFPMA on behalf of ICH.

If possible, please email copies of articles referencing MedDRA to mssohelp@mssotools.com. 

Official repositories such as regulatory databases or clinical trial registries are exempt from these guidelines.

What are the structural elements of the terminology in MedDRA?

The structural elements of the MedDRA terminology are as follows:

• SOC - Highest level of the terminology, and distinguished by anatomical or physiological system, etiology, or purpose
• HLGT – Subordinate to SOC, superordinate descriptor for one or more HLTs
• HLT – Subordinate to HLGT, superordinate descriptor for one or more PTs
• PT – Represents a single medical concept
• LLT – Lowest level of the terminology, related to a single PT as a synonym, lexical variant, or quasi-synonym (Note: All PTs have an identical LLT).

MedDRA is distributed in sets of flat extended ASCII delimited files. There is a different set of files for each available language. The Chinese, Czech, and Hungarian translations are distributed in UTF-8 format. For detail information as to file names, data record scheme, and record layout, see the MedDRA ASCII and Consecutive Files Documentation document, which can be downloaded from the MedDRA MSSO Web site.

Because MedDRA is intended to be used on multiple platforms, we do not have specific information on loading MedDRA onto every user's specific system or platform. However, if you'll look at the ASCII and Consecutive Files Documentation that comes with MedDRA, it gives information on the table names, field names and attributes, table joins, etc., which are required to create a relational database (using any database product) with the distributed MedDRA files.

For assistance loading MedDRA ASCII files into the MedDRA Browser, please go to the New MedDRA Subscriber Information page.

MedDRA does not have any specific hardware or software requirements. It does not require any particular operating system or version of an operating system. The terminology is delivered as a set of extended ASCII text files, with Chinese, Czech, and Hungarian translations distributed in UTF-8 format. The documentation accompanying the terminology is in .pdf format and describes the relationships between the files, which can then be used to load the files into a database or software application. The MedDRA text files can be loaded into all of the commonly used database management systems (e.g., MS Access ®, MS SQL Server ®, Oracle®). All software applications commonly used in the pharmaceutical industry can either load MedDRA directly or through a load utility.

MedDRA is delivered in text file format. As of MedDRA Version 16.0, the total size of all data files for the English version (excluding the history file) is 13.5 MB.

Chinese, Czech, Dutch, French, German, Hungarian, Italian, Japanese, Portuguese, and Spanish MedDRA translations are currently available on the MSSO Web site Downloads page.

The English versions of MedDRA are made available on 1 March and 1 September of each year.  Available EU, Chinese, and Japanese translations of MedDRA are made available two weeks after the English version, or approximately 15 March and 15 September.

Subscribers may download translations of MedDRA as long as they have their User ID, Password, and the Unzip password. The MedDRA Help Desk only gives this information to the designated point of contact on the subscription; other members are directed to get subscriber specific information from their company's point of contact.

The concept and contents of the Japanese version of MedDRA are exactly the same as English. Because of language, culture, and medical practice, differences between the Japanese and English MedDRA versions exist. The Japanese version of MedDRA, like other translations, contains duplicate translations of terms at the LLT level. However, MedDRA Japanese version provides an additional J-currency field to ensure the MedDRA Japanese current terms are flagged as unique. See the MedDRA/J web page for more of an explanation of the MedDRA Japanese version currency criteria.

Drug coding is out of the scope of MedDRA. There are terminologies designed specifically for coding drugs and chemicals that would assist you in this type of coding.

The MSSO advises a single change-over date when the new version of MedDRA becomes effective; the first Monday of the second month after the release date is advised. Please refer to the MSSO recommendation document for additional information. For the current release change-over date, please visit the MedDRA Subscribers page.

The MSSO recommends organizations to follow the Best Practices which are endorsed by the MedDRA Management Board and provide options and recommendations for the implementation and versioning for clinical trials.

For recent changes to MedDRA, refer to the What's New supporting document found in the Terminology Downloads section of the web site. (Login required)

Changes within the version are posted on the Supplemental Changes page. (Login required)

With the advent of the more sophisticated Standardised MedDRA Queries, the current SSCs within MedDRA will no longer be maintained or distributed. The MSSO has archived the existing SSC files. These files are available for download on the Archived SSCs page (Subscriber login required). Please note that the SSCs are based upon linkages at the PT level and that in each subsequent version of MedDRA, PTs may be demoted, and new PTs may be added to better represent the PT concept. Therefore, if you use the archived SSC files with a version other than 9.1, there may be terms that are no longer linked to the SSC as they were in Version 9.1. Subsequently, the SSC may no longer find the same cases as they did in Version 9.1.

Some (but not all) ICD-9 terms were incorporated in the first implementable version of MedDRA (Version 2.1) to support migration of ICD-9 coded data. Since then, updates to ICD-9 terms have not been applied to MedDRA.

One ICD-9 concept can be linked to multiple MedDRA terms at multiple levels. The user needs to be aware that equivalencies between the two (ICD-9 and MedDRA codes) are based on concepts and not string matches.

There are no plans to update the ICD-9 to MedDRA.

The National Cancer Institute developed the Common Terminology Criteria for Adverse Events (CTCAE) which is used for adverse event reporting in oncology clinical trials. A mapping between CTCAE v3.0 and MedDRA v11.0 was established and this mapping can be accessed on the Downloads web page. In May 2009, a major revision of CTCAE was released (CTCAE v4.0) This version of CTCAE is MedDRA v12.0 compatible at the Adverse Event term level where each CTCAE term is a MedDRA LLT. CTCAE v4.0 includes 764 AE terms and 26 'Other, specify' options based on the 26 MedDRA SOCs for reporting text terms not listed in CTCAE. Adverse Event terms in CTCAE v4.0 are grouped according to their primary SOC allocation in MedDRA. Since CTCAE v4.0 is MedDRA compatible, no mapping is needed between the two terminologies. Please refer to the NCI's Cancer Therapy Evaluation Program web site for further information on CTCAE.

The rule to mandate the use of MedDRA has been published in the Federal Register for comment.

MedDRA is an international medical terminology designed to support the classification, retrieval, presentation, and communication of medical information throughout the medical product regulatory cycle. Since November 1997, the FDA has replaced its Spontaneous Reporting System (SRS) and the Coding Symbols for Thesaurus of Adverse Reaction Terms (COSTART) Terminology with the new Adverse Events Reporting System (AERS) and the MedDRA Terminology. The use of MedDRA is inevitable since the rule to mandate the use of MedDRA was in the OMB office and the 90-day review period was up in mid-November 2002. To date, the mandate regarding the use of MedDRA is still a part of the proposed rule for post-marketing reporting.

Currently, there are no published FDA regulations or policies concerning the use of the primary System Organ Class ( SOC ) allocation of individual terms for either pre-marketing or post-marketing adverse event reports.  The understanding that MedDRA was built by consensus between regulators and industry representatives means that the establishment of criteria for the primary allocation of Preferred Terms (PTs) was a consensus decision. To see additional MSSO comments concerning the primary SOC allocation, please see the document Primary SOC Allocation in MedDRA.

Using the Primary SOC allocation:

• Decreases the risk of double counting events in cumulative outputs (when using secondary SOC allocations, there is the potential for finding multiple instances of the same event scattered over a number of SOCs, which may be confusing)
• Provides for consistent representation of specific events between companies and regulators (as MedDRA is a standard terminology)
• Allows secondary SOC allocations to be used for other types of scientific analyses.

The MSSO is not certain about what the "final" rules and regulations will be concerning this issue.  However, we recommend that if users choose to use a secondary SOC allocation for individual terms, they should be able to produce the term under the primary SOC allocation in the event of a regulatory inquiry.   Additionally, regulators from other regions are starting to request reports using only the primary SOC path.

The primary SOC allocation is what is expected and recommended when using an internationally accepted, standardized terminology, but users also have the option of providing documentation as to why they believe the secondary SOC allocation might better represent their data; this documentation should be submitted to the MSSO in the form of a Change Request to change the primary SOC allocation for a specific term.  Some companies set up their systems to either view all SOC allocations, or through pilot conversions, set it up to view the secondary SOC allocations. However, the MSSO would advise caution in this case.  See the MedDRA Points to Consider section for the MedDRA Term Selection:  Points to Consider document, which refers to the recommendation to use the SOC assignments the way they are, and the procedures for correcting them through the Change Request process. 

As a reminder, the "Points to Consider" document is an ICH -endorsed companion document for MedDRA which provides the user community with a standardized approach to term selection/coding with MedDRA.

There is an agreement to the international order of SOCs, which is included with each MedDRA release and can be found in either the Introductory Guide supporting document (Version Documentation) or in the Intl_ord.asc file.

As of right now, there is no required date by which regulators start using the next version of MedDRA. The post-market reporting document authored by the MSSO recommends that organizations update their systems with the latest version of MedDRA by 60 days after the release of MedDRA. This does not mean that all data must be re-coded, just that all organizations would start using the latest version of MedDRA. The EMA has, in some cases, required users to recode data back to 1995.

During the 60 day period, it was envisioned that organizations would review the changes in MedDRA and make what changes they (the organization) thought were necessary. Typically, this involves reviewing and re-coding LLTs that have become non-current, reviewing new direct matches to the verbatims and, if resources allow, reviewing medically “better” terms. These steps are not required but are a typical best practice of many organizations.

Although the third party licensing agreement requires both a Sponsor and a CRO to carry a MedDRA subscription, there are no restrictions on disseminating statistical reports to investigators outside your organization who were involved in a clinical trial. In this case, the intent is of a business nature and not to distribute the MedDRA terminology. The MSSO realized that MedDRA codes sometimes appear in this data.