Reviewing the ICD-10 classification of haematological neoplasms on its way to ICD-11
Tokyo, Japan 16-22 October 2005
Thus the content of the Blue Book for Lymphomas and Leukaemias , the structures of ICD-O-3 and the existing ICD-10 could be respected.
Bringing this section in line with ICD-O-3 and the current state of science will achieve a smoother transition to ICD-11 as crosswalks at the level of entities will prevent major breaks in health statistics.
The significant entities in haemato-oncology at the current state of science could be placed in the existing part of ICD-10. Because of the restrictions imposed by existing 3- and 4-character categories, the main focus was set on the correct placement of the content. The overall view of modifications in figure 1 gives a first impression of the approach and identifies “hot spots”. Numbers of changes made are as follows (figure 2): Of 20 3-character categories 7 (35%) were modified, 2 new categories were introduced and none were removed. Overall percentage of changes of relevant 3-character categories was 45 (%). Of 126 4-character subcategories 57 (45%) were modified, 31 (24%) new subcategories were introduced and 12 (9%) were removed from the classification. Overall percentage of changes of relevant subcategories was 79 (%).
This number of changes might seem overwhelming at first sight.
Indeed changes of content at a 3 character category level reflect the new knowledge in the field. They do not always affect the content of a 3 character category. A good example would be the change of the title of C84. The old as well as the new title reflect the same content only the text had to be adapted to new knowledge. As the number of available 4 character subcategories of C84 was not sufficient to list all relevant entities, the new C86 was created. The entities listed under this new code were comprised in C84.5 in the past (C84.old=C84.new+C86.new).
A price for the integration of all entities into the somewhat outdated system of the ICD-10 is the separation of closely related diagnoses into different 3- character categories on one side and grouping of relatively unrelated entities into one 3-character category on the other side.
C88.1, Alpha heavy chain disease, is now known to mean exactly the same as C88.3, Immunoproliferative small intestinal disease (Mediterranean disease). The name of this disease was different according to the region the patient was diagnosed. The frequencies for C88.3 in the countries concerned apparently have decreased significantly, nevertheless it was decided to keep this code
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