Background
The new International Classification of Diseases—11th revision (ICD-11) succeeds ICD-10. In the three decades since ICD-10 was released, demands for detailed information on the clinical history of a morbid patient have increased.
Methods
ICD-11 has now implemented an addendum chapter X called “Extension Codes”. This chapter contains numerous codes containing information on concepts including disease stage, severity, histopathology, medicaments, and anatomical details. When linked to a stem code representing a clinical state, the extension codes add significant detail and allow for multidimensional coding.
Results
This paper discusses the purposes and uses of extension codes and presents three examples of how extension codes can be used in coding clinical detail.
Conclusion
ICD-11 with its extension codes implemented has the potential to improve precision and evidence based health care worldwide.