The World Health Organization (WHO) Eleventh Revision of the International Classification of Diseases (ICD-11) has now come into effect, with the latest update going online today.

The ICD provides a common language that allows health professionals to share standardized information across the world. It is the foundation for identifying health trends and statistics worldwide, containing around 17 000 unique codes for injuries, diseases, and causes of death, underpinned by more than 120 000 codable terms. By using code combinations, more than 1.6 million clinical situations can now be coded.

Compared with previous versions, ICD-11 is entirely digital with a new user-friendly format and multilingual capabilities that reduce the chance of error. It has been compiled and updated with input from over 90 countries and unprecedented involvement of healthcare providers, enabling evolution from a system imposed on clinicians into a truly enabling clinical classification and terminology database that serves a broad range of uses for recording and reporting statistics on health.

“International classification of diseases is the cornerstone of a robust health information system”, said Dr. Samira Asma, the Assistant Director-General for Data, Analytics, and Delivery for Impact at the World Health Organization (WHO). “ICD has been instrumental in helping us respond to the COVID-19 pandemic using standardized data and continues to be crucial for tracking progress towards universal health coverage. We hope all countries will take advantage of ICD-11’s powerful new features.”

Among other updates, ICD-11 improves the clarity of terms for the general public and facilitates the coding of important details such as the spread of cancer or the exact size and type of a fracture. The new version also includes updated diagnostic recommendations for mental health conditions and digital documentation of COVID-19 certificates.

These updates reflect recent progress in medicine and advances in scientific understanding. For example, codes relating to antimicrobial resistance are now aligned with the Global Antimicrobial Resistance Surveillance System (GLASS). ICD-11 is also more capable of capturing data on healthcare safety, thus identifying and reducing unnecessary events that may harm health such as unsafe workflows in hospitals.

ICD is used by health insurers who make reimbursement decisions on the basis of ICD coding, by national health programme managers, by data collection specialists, and by anyone who tracks progress in global health and determines health resource allocation.

“A key principle in this revision was to simplify the coding and provide users with all necessary electronic tooling – this will allow health-care professionals to more easily and completely record conditions,” says Dr. Robert Jakob, Team Lead, Classifications Terminologies and Standards, WHO.

In addition to coding and capability updates, ICD-11 includes new chapters on traditional medicine, sexual health, and gaming disorder – which has now been added to the section on addictive disorders.

ICD-11 was adopted at the World Health Assembly in May 2019 and the Member States committed to start using it for mortality and morbidity reporting in 2022. Since 2019, early adopter countries, translators, and scientific groups have recommended further refinements to produce the version that is posted online today.