ICD-11: Classifying disease to map the way we live and die

July 17, 2018

There are few truer snapshots of a country’s well being than its health statistics. While broad economic indicators such as Gross Domestic Product may skew impressions of individual prosperity, data on disease and death reveal how a population is truly faring.

The International Statistical Classification of Diseases and Related Health Problems (ICD) is the bedrock for health statistics. It maps the human condition from birth to death: any injury or disease we encounter in life — and anything we might die of — is coded. Not only that, the ICD also captures factors influencing health, or external causes of mortality and morbidity, providing a holistic look at every aspect of life that can affect health.

These health statistics form the basis for almost every decision made in healthcare today — understanding what people get sick from, and what eventually kills them, is at the core of mapping disease trends and epidemics, deciding how to program health services, allocate healthcare spending, and invest in R&D.

ICD codes can have enormous financial importance, since they are used to determine where best to invest increasingly scant resources. In countries such as the USA, meanwhile, ICD codes are the foundation of health insurance billing, and thus critically tied up with healthcare finances.

Crucially, in a world of 7.4 billion people speaking nearly 7000 languages, the ICD provides a common vocabulary for recording, reporting and monitoring health problems. Fifty years ago, it would be unlikely that a disease such as schizophrenia would be diagnosed similarly in Japan, Kenya and Brazil. Now, however, if a doctor in another country cannot read a person’s medical records, they will know what the ICD code means. Without the ICD’s ability to provide standardized, consistent data, each country or region would have its own classifications that would most likely only be relevant where it is used. Standardization is the key that unlocks global health data analysis.

On June 18, 2018, 18 years after the launch of ICD-10, WHO released a version of ICD-11 to allow Member States time to plan implementation. This is anticipating the presentation of ICD-11 to the World Health Assembly in 2019 for adoption by countries. Over a decade in the making, this version is a vast improvement on ICD-10.

First, it has been updated for the 21st century and reflects critical advances in science and medicine. Second, it can now be well integrated with electronic health applications and information systems. This new version is fully electronic, significantly easier to implement which will lead to fewer mistakes, allows more detail to be recorded, all of which will make the tool much more accessible, particularly for low-resource settings.

A third, important feature is that ICD-11 has been produced through a transparent, collaborative manner, the scope of which is unprecedented in its history. The complexity of the ICD has sometimes made it seem like an esoteric health tool requiring months of training — of the number of deaths reported in the world, those coded correctly were about one third. An overriding motive in this revision was to make the ICD easier to use.