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March 1995 |
International Classification of Diseases, Tenth Revision
The Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) is the most recent revision of the work begun in 1893 with the Bertillon Classification, or International List of Causes of Death. Over the past 100 years, ten revisions have been made, augmenting the 161 causes of death in Bertillon’s original list to the current 2,036 categories, presented in 21 chapters.
Until the Fifth, the international revision conferences were convened by the Government of France; beginning with the Sixth Revision, in 1948, the World Health Organization has been responsible for the revision, publication, and dissemination of this work.
The need to expand the number of categories in the Classification, owing to the discovery of new diseases (such as AIDS) and a better understanding of many others, as well as to include new factors that impact health status, led to the adoption of an alphanumeric coding system in the Tenth Revision. Utilizing a letter as the first character, followed by two (or three) digits, a total of 2,600 three-character categories and 26,000 four-character subcategories are available (versus 1,000 and 10,000, respectively, in ICD-9). Twenty-five of the 26 available letters were used; the letter "U" was left vacant for future additions and changes and for special studies between revisions. Consequently, 2,500 categories are actually available, 2,036 of which have been used.
The sequence of chapters in ICD-10 is almost the same as in ICD-9. However, disorders of the immune mechanism, which in the ICE-9 had been included with endocrine, nutritional and metabolic diseases, in the ICD-10 are included with diseases of the blood and blood-forming organs. The new chapter, III. Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism follows the "Neoplasms" chapter and shares the letter D with it. It was not possible to accommodate all the required detail for the chapter on diseases of the nervous system and sense organs under one letter in 100 three-character categories’; hence, three separate chapters were created: VI Diseases of the nervous system, having the letter G, and the two chapters VII Diseases of the eye and adnexa and VIII Diseases of the ear and mastoid process sharing the letter H. Also, chapters Diseases of the genitourinary system, pregnancy, childbirth and the puerperium, Certain Conditions originating in the perinatal period, and Congenital malformations, deformations and chromosomal abnormalities were brought together as contiguous chapters XIV to XVII.
Substantial changes were introduced in chapters V Mental and behavioral disorders, XIX Injury, poisoning and certain other consequences of external causes, and XX External causes of morbidity and mortality. In ICD-9 the latter was a supplementary classification of external causes of injury and poisoning. The ICD-9 supplementary classification of factors influencing health status and contact with health services became chapter XXIICD-10.
The dual classification scheme introduced ion the Ninth Revision for etiology and manifestation, known as the "dagger and asterisk," has been retained and expanded in the ICD-10. The basic cause or underlying disease process is assigned a code marked with a dagger (†), and its clinical manifestation another, marked with an asterisk (*), with the two used jointly. An example of this is the coding of tuberculosis of the spinal column, which is coded as A18.0† (Chapter I – Certain infectious and parasitic diseases) as the basic cause and as M49.0* (Chapter XIII – Diseases of the musculoskeletal system and connective tissue) as its clinical manifestation.
The Revision Conference agreed to retain the definitions of live birth and fetal death, as well as of maternal death, as they appeared in the Ninth Revision. However, two additional definitions were adopted, for "pregnancy-related death" and "late maternal death." The purpose of these is to improve the quality of maternal mortality data and provide alternative methods of collecting data on deaths during pregnancy or related to it, as well as to encourage the recording of deaths from obstetric causes occurring more than 42 days following termination of pregnancy. The Conference recommended that countries consider the inclusion on death certificates of questions regarding current pregnancy and pregnancy within one year preceding death. In addition, according to the ICD-10 the perinatal period commences at 22 completed weeks (154 days) of gestation (the time when birth weight is normally 500 g), and ends seven completed days after birth.
Another important point related to the ICD-10 is the concept of a "family of classifications", of which the list of three-character categories is the core. It has been clear for some time, especially since the 1970s when the Ninth Revision was prepared, that no single classification can meet all the needs related to the organization of knowledge in health, including detailed information on all known diseases as well as external causes, social and environmental factors that impact health, procedures in medicine, disabilities, lay reporting, etc.
Hence, the International Conference for the Tenth Revision of the International Classification of Diseases (Geneva, Switzerland, 1989) recommended, and the 43rd World Health Assembly (1990) approved, in relation to this subject:
"Endorsed the recommendations of the Conference regarding
The scheme with the "members" of the family of classifications is shown in Figure 1.
Figure 1
Family of disease and health-related classifications
The ICD-10 is presented in three volumes, with the following contents:
-Volume 1
Introduction; WHO Collaborating Centers for Classification of Diseases; Report of the International Conference for the Tenth Revision of the International Classification of Diseases; List of three-character categories; Tabular list of inclusions and four-character subcategories; Morphology of neoplasms; Special tabulation lists for mortality and morbidity; Definitions; Regulations regarding nomenclature.
-Volume 2
Description of the International Statistical Classification of Diseases and Related Health Problems; How to use the ICD; Rules and guidelines for mortality and morbidity coding; Statistical presentation; History of the development of the ICD.
-Volume 3
Alphabetical index to diseases and nature of injury; External causes of injury; Table of drugs and chemicals; Corrigenda to Volume 1.
Meeting of WHO Collaborating Centers – Caracas, 1994
From 18 to 24 October 1994, in Caracas, Venezuela, the Venezuelan Center for the Classification of Diseases (CEVECE), WHO Collaborating Center for the Classification of Diseases in Spanish, hosted the annual Meeting of Director of Collaborating Centers. In attendance were the Directors of the Collaborating Centers for Classification of Diseases in Brazil, North America, Nordic countries, London, France, Australian, and Kuwait (the new Collaborating Center for the Arabic language), as well as representatives of several national centers, WHO, PAHO and world experts in the field.
At the meeting, each Collaborating Center presented a report on its activities related to special studies on morbidity and mortality, training of personnel, and preparations for the implementation of ICD-10. In addition, reports were presented on the activities of WHO, PAHO, and SEARO (WHO Regional Office for South-East Asia), and national activity reports were presented by representatives of Canada, The Netherlands, Mexico, and Japan.
There were also presentations on various analytical studies, such as on multiple causes of death, use of the dagger and asterisk coding system, use of mortality data as basic and complementary information for epidemiological surveillance, use of the Classification of Procedures in Medicine and the Classification of Impairments, Disabilities and Handicaps, inter alia. Special mention should be made of the following presentations:
Finally, the implementation of ICD-10 was discussed (see below).
Although the International Conference for the Tenth Revision recommended the use of the ICD-10 beginning in January 1993, several problems have delayed implementation. Very few countries have already begun to use the ICD-10 for coding mortality and morbidity. Denmark is one, having begun using the ICD-10 in 1994; the ICD-9 was never used in that country, which went directly from using the Eighth to the Tenth ICD Revision.
Throughout the world, preparations are under way for general use of the Tenth Revision beginning in January 1996, as is expected in virtually the entire Region of the Americas.
To implement the ICD-10 in our Region, PAHO is preparing training workshops for the second half of 1995 to instruct personnel in the use of the Tenth Revision. Three workshops will be conducted in Spanish, as a joint activity of PAHO and CEVECE, and two in English, for Caribbean countries, as a joint effort by PAHO and the Collaborating Center for North America. Following the workshops, countries will undertake national-level training and reorientation of coders.
The Brazilian Center will be in charge of activities for implementation of the ICD-10 (in Portuguese) in Brazil in 1996. In north America, use of the ICD-10 will commence in 1997, with retroactive dual coding (ICD-9 and ICD-10) of data for 1995 and 1996, and in the French-speaking countries of the Hemisphere (with the support of the Centers for North America and France) between 1996 and 1997.
For implementation of the ICD-10,all three volumes of the ICD are needed in each language. As of March 1995 the situation is as follows: English and French, all three volumes are available. Portuguese, Volumes 1 and 2 are available; Volume 3 is in preparation. Spanish, Volume 1 is in press; Volume 2 is under review; and Volume 3 (Index) is in preparation.
It is important to note that the implementation of a new revision of the International Classification of Diseases does not merely imply a change in the codes assigned to diseases and related health problems. Further, it should be taken as an opportunity for review of everything connected to health statistics and health situation analysis, indispensable ingredients in support of decision-making and the implementation of policies and programs geared toward improving the health situation of the population, understanding health as an inherent human right and the basis for personal and social development that is both comprehensive and equitable.
Source: Division of Health and Development, Health Situation Analysis Program, HDP/HDA, PAHO.
