Development of an ICD Coding Definition for Inflammatory Bowel ...

such as epidemiological and statistical analysis of morbidities and mortalities,
reimbursements, and surveillance. The variety and extensiveness of the ICD codes enable
us to draw a fair picture of the patient‘s medical status. The International Classification of
Diseases is published and maintained by the World Health Organization and is revised
periodically [38].
2.3.1 International Classification of Diseases, 9 th revision, clinical modification (ICD-
9-CM)
In 1977 ICD-9 was published by the WHO. This version was extended with extra
morbidity codes and a section of procedure codes. The extension was called ICD-9-CM,
which has over 14,000 codes than can be shown with a maximum of 5 digits based on the
level of specificity. (Appendix 1)
2.3.2 International Classification of Diseases, 10 th revision (ICD-10)
Development of ICD-10 began in 1983 and was completed in 1992; however, transition
from the ninth to tenth revision of ICD has not been implemented in several health care
databases such as physician claims database.
Canada has introduced an enhanced version of ICD-10 called ICD-10-CA. It benefits
from an alpha-numeric format ranging from 3 to 6 characters [39] (Appendix1).
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