From ICD-6 to ICD-11: history and what improved

Older than WHO itself

The classification is older than the World Health Organization itself. Counting causes of death began long before ICD-11.

From Bills of Mortality to a list

In 1662, John Graunt's work on the London Bills of Mortality began the statistical study of disease. In 1855, the International Statistical Congress adopted a list of a hundred and thirty-nine rubrics, and William Farr's arrangement, by aetiology and then anatomical site, survived. In 1893 came the Bertillon classification of causes of death, adopted by several countries and cities.

• 1662 · Graunt · His study of London's Bills of Mortality began the statistics of disease.
• 1855 · Farr · A list of 139 rubrics was adopted. Farr's arrangement, by aetiology then site, survived.
• 1893 · Bertillon · His classification of causes of death was adopted by several countries and cities.

Conferences, then WHO

In 1900, the first International Conference revised the list: twenty-six countries, a hundred and seventy-nine groups, with a revision every ten years. After 1946, the World Health Organization took over responsibility. The Sixth Revision was adopted in Paris in 1948, and the first World Health Assembly adopted regulations to follow it.

• 1900 · Conference · The first International Conference for the revision of the list: 26 countries, 179 groups, with revisions every ten years.
• 1946 to 1948 · WHO · The WHO Interim Commission was entrusted with the revision. The Sixth Revision was adopted in Paris in 1948, and the first World Health Assembly adopted regulations.

Six revisions, six dates

Under WHO there have been six revisions. The sixth in 1948. The seventh in effect from nineteen fifty-eight. The eighth from nineteen sixty-eight. The ninth from nineteen seventy-nine. The tenth from nineteen ninety-three. And the eleventh from the first of January twenty twenty-two, adopted by the World Health Assembly in May twenty nineteen.

• 6th revision: 1948
• 7th revision: in effect 1 Jan 1958
• 8th revision: in effect 1 Jan 1968
• 9th revision: in effect 1 Jan 1979
• 10th revision: in effect 1 Jan 1993
• 11th revision: in effect 1 Jan 2022

The same job, rebuilt

What improved? WHO's own table of major changes lists a new code structure: four-character stem codes, a letter in the second position, and extension codes. Postcoordination and clusters replace the dagger and asterisk system, while the ability to code a cause and a manifestation remains. And the main diagnosis is now defined as the reason for admission, after assessment at the end of the stay.

• The structure · New scheme · Four-character stem codes, a letter second, extension codes.
• Combining · Clusters · Postcoordination replaces dagger and asterisk. Cause and manifestation can still be coded.
• Main diagnosis · Admission · The reason for admission, after assessment at the end of the stay.

Check yourself

Pause and think. In ICD-11, how is the main diagnosis for morbidity defined? The answer: The reason for admission, after assessment at the end of the stay. WHO's table of changes states the main diagnosis is the reason for admission, after assessment at the end of the stay.

• The most resource-intensive condition
• The first condition recorded on the chart
• The reason for admission, after assessment at the end of the stay
• The most severe condition regardless of admission

Keep these in mind

Counting causes of death began in the seventeenth century. The international list dates from 1893 and 1900. WHO has run the revisions since 1948. And ICD-11 has been in effect since the first of January twenty twenty-two.

• Counting causes of death began in the 17th century
• The international list dates from 1893 and 1900
• WHO has run the revisions since 1948
• ICD-11: in effect from 1 January 2022