Origins and evolution of the International Classification of Diseases system

ICD: History And Revision

History of the ICD - how far back does it go?

The International Statistical Classification of Diseases and Related Health Problems (ICD-10) was created initially by the United Nations and then used by the World Health Organization (WHO) as a method of coding diseases in a comprehensive and comprehensible manner for international health organizations. The fundamental principles behind the ICD are as old as the World Health Organization itself.

The current ICD-10 began being used by WHO Member States in 1994. However, the desire to create an international classification system for diseases is actually far older. ICD-10 is "the latest in a series which has its origins in the 1850s. The first edition, known as the International List of Causes of Death, was adopted by the International Statistical Institute in 1893. WHO took over the responsibility for the ICD at its creation in 1948 when the Sixth Revision, which included causes of morbidity for the first time, was published. The World Health Assembly adopted in 1967 the WHO Nomenclature Regulations that stipulate use of ICD in its most current revision for mortality and morbidity statistics by all Member States" (ICD, 2011, WHO).

The reason the ICD lasted so long is because it was allowed to be a 'living' document, constantly evolving and adding to the different symptoms, causes, social factors, other external causes, and mitigating or enhancing factors that accompany diseases. The diverse range of codes ensures that new diseases and diagnoses can be recorded. The earliest records of disease only recorded mortality. Although details about causes of death were kept in the 19th century, not until 1945 was it decided that "it would be advantageous to consider classifications from the point-of-view of morbidity and mortality, since the problem of joint causes pertained to both types of statistics" (History of the development of the ICD, 2011, WHO).

Why are we switching?

For most of its history, the ICD has been revised approximately every ten years. The new version to be implemented to replace the ICD-10 will reflect expanded knowledge about genetically-specific medicine, genome sequencing and disease gene mapping, "novel disease and epidemiology and intervention effectiveness modeling (e.g. GBD, cost-effectiveness), as well as web-driven information sharing and computer-based analysis" which have affected "many aspects of our current understanding and interpretation of health" (ICD Revision Project Plan, 2010, WHO). It is essential that the ICD reflect the most current knowledge we possess as a society about biotechnology and also that it reflects impact the Internet has had upon medicine.

Costs of the ICD-10?

While data-tracking can be expensive, the knowledge gained from health statistics is so valuable it can ultimately save lives, and result in cost savings for nations around the world. In fact, it is partially because of the costs of data-gathering that it is so essential that an international body like WHO is able to keep track of statistics, if developing world nations cannot do so themselves. Furthermore, the data amassed also pertains to medical record-keeping and the costs of different ways of providing healthcare, so the connection between resource allocation at a national level and public health can be assessed. For example, although the United States spends more on health care than any other country in the world, average U.S. life expectancy ranks 27th in the world, at 77 years, which many attribute to America's lack of nationalized, comprehensive healthcare for all its citizens (Healthcare spending, 2011, UC Atlas of Inequality).

Implementation issues

Another reason for the revision is the desire to involve developing countries more actively in the revision process, so that the ICD-11 will be well-suited to their needs. This, it is hoped, will foster greater utility of the system. Additionally, national modifications will be allowed and WHO is currently embarking upon creating ICD-10-XM, a cross-country version, which incorporates all of the national code modifications (ICD Revision Project Plan, 2010, WHO). All member nations of WHO must use the ICD system, and the greater accessibility of knowledge facilitated by the Internet will hopefully help, rather than isolate the nations most desperately in need of innovative health solutions. Frequent online revisions and greater connectivity will be a source of greater knowledge and insight.