Adverse Reaction Terminology: MedDRA and WHO-ART

Detection and reporting on adverse drug reactions (ADRs) is an integral part of modern medicine. It is equally important in everyday healthcare practice and when conducting clinical trials for new therapeutics.

Healthcare professionals are required to report adverse reactions they encounter in practice with as much detail as they can acquire. Consequently, pharmaceutical companies around the globe receive numerous reports from doctors and pharmacists about suspected ADRs. Each company is required to submit these reports to the drug regulatory agency of the country, or countries, in which the drug is used.

However, healthcare professionals from different countries use different medical terminology in reporting their ADRs.

Today, when reporting of such events is done electronically, the operating systems need to use and interpret standardized terminology for a more synchronized reporting.

The true value of the ADR-reporting system depends on its ability to understand medical terms deposited in the official adverse reaction thesauri. In other words, terms used by a local system need to be mapped in the back end of the system to a corresponding term in the official medical vocabulary.

The major thesauri that have contributed to the improvement of global adverse reaction reporting are MedDRA and WHO-ART.

Further in this article, we relate to the main traits of these medical terminologies.

What Is MedDRA?

Medical Dictionary for Regulatory Activities (MedDRA)  is a clinically-validated international dictionary of medical terminology. It is used for the classification of adverse event information associated with the use of pharmaceuticals and medical devices.

MedDRA is also a sophisticated thesaurus of highly specific, standardized medical terms that facilitates the sharing of regulatory information for pharmaceutical products. It is used for registration, documentation, and safety monitoring of medicinal products.

MedDRA is considered a standard in the biopharmaceutical industry, and it can be used before and after the products’ authorization. It also assists researchers and healthcare professionals for more accurate data entry, retrieval, evaluation, and presentation.

Its use is essential in the development and regulation of pharmaceuticals, vaccines, biologics, and medical devices. Therefore, its primary beneficiaries are pharmaceutical companies and CROs, while its integration in healthcare systems helps healthcare professionals in their routine work.

MedDRA History

MedDRA was developed by the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) in the late 1990s. Its founding members are the leading regulatory agencies and health associations across the world, such as the EU, FDA, EFPIA, WHO, JPMA, etc.

Today, it is regulated by the ICH MedDRA Management Committee that oversees the operations of the MedDRA Maintenance and Support Services Organization (MSSO). MSSO updates MedDRA and distributes it through sets of extended ASCII delimited files.

The system is continually being enhanced to meet the needs of evolving medical research. MSSO oversees a vast network of users on its forum that update each other on the best practices on MedDRA use.

Who Uses MedDRA?

The dictionary is mastered in English and translated initially to Japanese. Today, MedDRA is a multilingual platform, as it has been translated into Chinese, German, French, Korean, Italian, Hungarian, Czech, Dutch, Portuguese (including Brazilian dialect), Russian, and Spanish.

Multiple language options assist users in operating MedDRA in their native language, while the primary medical term remains unaltered in the form of a code. This type of interoperability makes this technology the most desirable in clinical trials.

How Does MedDRA Work?

Adverse event data is MedDRA coded by trained professionals from medical histories, clinical trial data, or other applicable sources that have been collected by healthcare practitioners.

Each MedDRA term is displayed as an eight-digit numerical code. The codes are structured in a sophisticated hierarchy, which is essential for flexible data retrieval and transparent presentation of data. Moreover, distinct hierarchies make it available to retrieve data by group according to specific criteria. MedDRA is used for analyzing individual medical events, or it can be queried for the retrieval of more generalized information that relates to a particular organ group.

Its hierarchy has five levels:

• System Organ Class (SOC)
• High-Level Group Terms (HLGT)
• High-Level Terms (HLT)
• Preferred Terms (PT)
• Lowest Level Terms (LLT)

Each level has its way of specificity, with LLT being the most specific term. The Standardized MedDRA Queries (SMQs) are groups of terms that facilitate quick search.

Today, MedDRA is an integral part of the ICH e-submission standards: eCTD (ICH M8) and ICSRs (ICH E2B).

What Is WHO-ART?

The World Health Organization Adverse Reaction Terminology (WHO-ART) was developed in 1968 and since then maintained by the Uppsala Monitoring Centre (UMC), the WHO Collaborating Centre for International Drug Monitoring.

Originally developed in English, WHO-ART was translated into French, German, Spanish, Portuguese, and Italian.

WHO-ART’s design is flexible, and dynamic by nature, open for constant improvement.

It is an open-ended terminology thesaurus for coding of adverse reaction terms, built as a four-level hierarchical structure:

• System Organ Class (SOC)
• High-Level Terms (HLT)
• Preferred Terms (PT)
• Included Terms (IT)

The system served for over thirty years as the main dictionary of terminology for coding adverse events. However, since 2008, when MedDRA was officially implemented, WHO-ART is no longer actively maintained.

Since MedDRA has more granularity in its design, easier data exchange preferences, and enables data mining using large databases, it is considered as the preferred choice for a more accurate ADR monitoring.

In order to facilitate the transition between the two thesauri, WHO Uppsala Monitoring Centre (UMC) has developed with ICH/MSSO a mapping bridge from WHO-ART to MedDRA that allows conversion of legacy data from WHO-ART to MedDRA.

Although the mapping procedure does not go in the reverse direction (from MedDRA to WHO-ART), the WHO-ART databases have been updated with MedDRA terms that appear in WHO adverse reactions reports.

Leveraging Adverse Reactions Terminology in Modern Healthcare

Electronic reporting is becoming the main route for exchanging adverse information reports between healthcare systems, pharmaceutical and medical device companies, sponsors of clinical trials, and regulatory authorities worldwide.

Therefore, it’s safe to say that modern ADR reporting needs to rely on the use of advanced technology solutions. In other words, clinical software, including those used by investigators in clinical trials, should have a clear, streamlined MedDRA coding feature.

This way, reporting of adverse events will be improved across global healthcare systems, and not burdened with paperwork or low-level administrative works.

By implementing adverse reaction terminology in systems that clinical professionals use every day, all stakeholders could leverage the costs and benefits of treatments on a larger scale.