The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or disease. Under this system, every health condition can be assigned to a unique category and given a code, up to six characters long. Such categories can include a set of similar diseases.
The International Classification of Diseases is published by the World Health Organization (WHO) and used worldwide for morbidity and mortality statistics, reimbursement systems and automated decision support in medicine. This system is designed to promote international comparability in the collection, processing, classification, and presentation of these statistics. The ICD is a core classification of the WHO Family of International Classifications (WHO-FIC).
The ICD is revised periodically and is currently in its tenth edition. The ICD-10, as it is therefore known, was developed in 1992 to track mortality statistics. ICD-11 is planned for 2015 and will be revised using Web 2.0 principles. Annual minor updates and three-yearly major updates are published by the WHO. The ICD is part of a “family” of guides that can be used to complement each other, including also the International Classification of Functioning, Disability and Health which focuses on the domains of functioning (disability) associated with health conditions, from both medical and social perspectives.
In 1893, a French physician, Jacques Bertillon, introduced the Bertillon Classification of Causes of Death at theInternational Statistical Institute in Chicago. A number of countries adopted Dr. Bertillon’s system, and in 1898, theAmerican Public Health Association (APHA) recommended that the registrars of Canada, Mexico, and the United States also adopt it. The APHA also recommended revising the system every ten years to ensure the system remained current with medical practice advances.
As a result, the first international conference to revise the International Classification of Causes of Death convened in 1900; with revisions occurring every ten years thereafter. At that time the classification system was contained in one book, which included an Alphabetic Index as well as a Tabular List. The book was small compared with current coding texts.
The revisions that followed contained minor changes, until the sixth revision of the classification system. With the sixth revision, the classification system expanded to two volumes. The sixth revision included morbidity and mortality conditions, and its title was modified to reflect the changes: Manual of International Statistical Classification of Diseases, Injuries and Causes of Death (ICD).
Prior to the sixth revision, responsibility for ICD revisions fell to the Mixed Commission, a group composed of representatives from the International Statistical Institute and the Health Organization of the League of Nations. In 1948, the World Health Organization (WHO) assumed responsibility for preparing and publishing the revisions to the ICD every ten years. WHO sponsored the seventh and eighth revisions in 1957 and 1968, respectively.
In 1959, the U.S. Public Health Service published The International Classification of Diseases, Adapted for Indexing of Hospital Records and Operation Classification (ICDA). It was completed in 1962 and a revision of this adaptation – considered to be the seventh revision of ICD – expanded a number of areas to more completely meet the indexing needs of hospitals.
The U.S. Public Health Service later published the Eighth Revision, International Classification of Diseases, Adapted for Use in the United States. Commonly referred to as ICDA-8, this classification system fulfilled its purpose to code diagnostic and operative procedural data for official morbidity and mortality statistics in the United States.