Classifying diseases to map how humans live, die

There are renewed efforts to classify diseases and to map how humans live and die.

According to latest figures from the World Health Organisation (WHO), there are few truer snapshots of a country’s wellbeing than its health statistics.

While broad economic indicators such as Gross Domestic Product (GDP) may skew impressions of individual prosperity, data on disease and death reveal how a population is truly faring.

It has been demonstrated that the data captured through International Statistical Classification of Diseases and Related Health Problems (ICD) codes is of huge importance for countries.

It allows for the mapping of disease trends and causes of death around the world, which are key indicators both of the health of a population, but also the social determinants that link closely to health, such as the education, nutrition, and public infrastructure – in short, a snapshot of where a country’s vulnerabilities lie.

A country in which people live in crowded, inadequate housing with no clean water are inevitably likely to have a higher incidence of diarrhoeal disease.

The Global Health Observatory is WHO’s gateway to health-related statistics for over 1,000 indicators.

Data coded through the ICD populates the Global Health Observatory allowing WHO to report World Health Statistics annually.

These statistics are critical in tracking progress towards key targets such as the Sustainable Development Goals.

According to latest figures from the WHO, mortality data in the Global Health Observatory shows that while ischaemic heart disease and stroke are the top two killers worldwide, together accounting for 15 million deaths in 2015, zooming into the statistics by continent can show radically different pictures.

In Africa, lower respiratory infections and Human Immuno-deficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) cause the most deaths, whereas violence is in the top 10 causes of death in the Region of the Americas and the Eastern Mediterranean region.

Data clearly has huge significance in directing energy and resources in global health. Yet data also shows us a picture of what is happening in the world that is unhampered by bias or assumption.

For instance, data from the WHO’s 2018 World Health Statistics on global deaths on homicide and conflict show that the statistics do not always match the way these mortality data are reported in the media, for instance.

Indeed, 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.

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 health care 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 programme health services, allocate health care spending, and invest in Research and Development (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 health care 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.