What Is ICD?
ICD serves as the foundation for the identification of health statistics and trends globally. It contains about 55,000 codes for diseases, injuries, and causes of death. ICD can be considered as a common language that enables health professionals to share information on health across the globe.
It is developed by the World Health Organization (WHO) as a standard diagnostic tool to monitor the occurrence and prevalence of various diseases and conditions related to them.
International Classification of Diseases intends to classify diseases, conditions related to health, and external reasons for injury and disease so as to gather effective statistics on morbidity and mortality. The categories of ICD are functional for the decision support systems, reimbursement systems, and also serve as a common denominator that is used in language-independent documentation of health-related information.
There are several clinical applications of ICD, and it is not only used by just doctors but also researches, paramedics staff, policymakers, insurance companies. ICD helps to classify disease and gather diagnostic information for epidemiological, quality, and clinical purposes and also for insurance claims reimbursements.
History of ICD
The systematic statistical classification has its roots in the nineteenth century, and early heath statisticians did all the groundwork. These include Jacques Bertillon (1851-1922) and William Darr (1807-83).
The French government held the first International conference for the revision of the International Classification of Causes of Death in August 1900. The second conference took place in 1909, followed by a series of succeeding conferences in 1920, 1929, and 1938, and the French government organized all three of them. However, with its sixth revision, the World Health Organization become the custodian of the International Classification of Diseases (ICD).
The ICD-6 widened the approach for classification of diseases that are nonfatal, and WHO maintained its role for periodic revisions of ICD. A great number of clinical concepts have been introduced since then because of the requirement to establish comparability at the international level in clinical research as well as in public health.
The latest edition, ICD-10, was endorsed by the forty-third World Health Assembly in May 1990. Also, it is cited is more than 20,000 scientific articles. ICD-10 is being used by more than a hundred countries across the globe.
Usage of The ICD
ICD defines international standards for reporting health conditions and diseases and helps to identify health trends and statistics across the globe. It is considered as the diagnostic classification standard for all research and clinical purposes. ICD holds information about various diseases injuries, disorders, and other health conditions, that is listed hierarchically and comprehensively and allows for:
- Easy storage, analysis, and retrieval of information on health for evidence-based and well-informed decision making.
- Comparing and sharing health information between countries and settings, regions, hospitals.
- Data comparisons across different time settings in the same location.
The uses of ICD involve the occurrence and prevalence of the various disease, resource allocation trends, observing reimbursements, and following quality and safety guidelines. Moreover, they include counting of diseases, symptoms, deaths, injuries, causes for an encounter, factors influencing the status of health and other external disease causes.
ICD use in the United States
In 1962, the Public Health Service of the United States published the International Classification of Diseases, which was adapted for hospital records indexing and Operation Classification (ICDA). It further expanded ICD-7 (seventh edition) in various aspects to meet the indexing requirements of hospitals.
The U.S. Public Health service also published the ICDA-8 (eighth revision). It was utilized for official national mortality and morbidity statistics followed by the ICD-9 (ninth revision), Clinical Modification, which was published by the Department of Health and Human Services United States. It was used by hospitals and various other facilities for healthcare to describe the patient’s clinical picture in a better way. ICD-9 diagnosis component is entirely consistent with ICD-9 codes, and it remains a data standard for morbidity reporting.
ICD-10, with revisions that took place in 2003, further progressed to include both clinical code (ICD-10-CM) and the procedure code (ICD-10-PCS). However, in 2009, The Center for Medicare and Medicaid Services United States announced that it would be using ICD-10 by 2013 with complete compliance and involvement of all parties. But the deadline got extended two times. As a result, it did not happen until October 2015.
The causes of death in the United States have been classified according to each of its revision:
- ICD-1 – 1900
- ICD-2 – 1910
- ICD-3 – 1921
- ICD-4 – 1930
- ICD-5 – 1939
- ICD-6 – 1949
- ICD-7 – 1958
- ICD-8A – 1968
- ICD-9 – 1979
- ICD-10 – 1999
In the United States, death certificate that is compiled by the Centers for Disease Control and Prevention (CDC), the cause of death is coded as defined by the ICD that does not incorporate codes for human and system factors that are known as medical errors.
Versions of the ICD
ICD-9
ICD-9-CM (Clinical Modification) was used in the United States as a medical coding standard from 1979 to 2015. It is based o the international ICD specification developed by the World Health Organization (WHO).
ICD-9-CM Volume 1 and Volume 2
ICD-9-CM has three volumes. Volume 1 and 2 provide the same data but in two different formats, and these two volumes involve Diagnoses codes. Volume 1 has a tabular format and it organizes codes on the basis of the code number i.e., begins with 872.00, 872.01, etc. Whereas Volume 2 classifies codes into an index enabling you to search for codes in alphabetical order by their explanation.
ICD-9 Volume 1 has codes of four to five digits and has a format like WXX.YZ. Here ‘W’ reflects a digit or a letter ‘E or V’ and the last digital in optional.
ICD-9-PCS – Volume 3
Volume 3 involves Procedure Codes that map to codes of ICD-10-PCS. Procedure Codes define the treatment type that a patient ha received while he was in a hospital. Each visit to the hospital will have a minimum one Procedure code assigned to the patient as long as any type of treatment was provided. Codes of Volume 3 have three to four digits and they appear in XX.YZ format where the last digit is optional.
ICD-10
It is the tenth revision of the International Statistical Classification of Diseases and Health-Related Problems (ICD). It involves codes that hold crucial information regarding abnormal complaints, findings, epidemiology diseases, managing health external injuries, treating conditions, symptoms, signs, and social circumstances. ICD-10 contains more than 14,400 codes and they can be further extended to about 16,000 codes if using the optional sub-classifications.
ICD-11
WHO released a preview of ICD-11 on June 18, 2018. It has 55,00 codes for injuries and causes of diseases and deaths. ICD-11 simplifies the structure of coding enabling healthcare professionals to record medical conditions more easily.
ICD-11 is one of its kind and entirely electronic. It can integrate digital data sources, and it is free to download for individual use. Moreover, experts can easily contribute to the process of revision via the ICD-11 online platform that enables them to make comments and proposals for categories of ICD and definitions. It also adds gaming disorder to the section of addictive disorders and adds various types of allergies, cancers, diabetes, dementia, immune system disorders, infectious diseases.
It was introduced in May 2019 for global adoption, and it will be effective from January 2022.