International statistical classification of diseases and related health problems, tenth revision / Gerlind R. Brämer

- 32 - INTERNATIONAL STATISTICAL CLASSIFICATION OF DISEASES AND RELATED HEALTH PROBLEMS TENTH REVISION Gerlind R. Bramer3 The International Classification of Diseases (ICD) has, under various names, been for many decades the essen- tial tool for national and international comparability in public health. It has been the basis for the collection, classification, presentation and statistical analysis of mortality data for more than 80 years, has been used for morbidity statistics and studies for almost 40 years and is today one of the most quoted references in scientific journals on public health and epidemiology. The ability to exchange comparable data from region to region and from country to country, to allow comparisons from one population to another and to permit study of diseases over long periods is the particular strength of the ICD. This statistical classification has customarily been re- vised every 10 years in order to try to keep up with advances in medicine. Since its creation, the World Health Organization has carried out its statutory mandate of periodic revision of the ICD and the related nomenclature regulations, medi- cal certification and rules, as well as definitions and recommendations in the field of vital events. The Sixth Revision of the ICD in 1948 was the first to be carried out under the auspices of WHO. Since then the Organization has been responsible for the Seventh Revision (1955), the Eighth Revision (1965) and the Ninth Revision (1975), which came into force in 1979. The World Health Organization is now proceeding with the Tenth Revision and is assisted in this work by eight WHO col- laborating centres in different parts of the world. The preparation of a decennial revision of the ICD involves a set of remarkably varied activities, such as: meetings of the heads of WHO collaborating centres for the classification of diseases, Expert Committee meet- ings, presentation of proposals which in turn elicit the presentation of counterproposals, field trials, submis- sion of successive drafts to WHO Member States, analy- sis of comments and suggestions from nongovernmen- tal and governmental organizations and institutions as well as from individuals. Thus, each revision represents a series of transactions amongst multiple opinions. As the culmination of the work a final draft is presented for the approval of an International Revision Conference and then for adoption by the World Health Assembly. The International Conference for the Tenth Revision has been scheduled for 1989 and ICD-10 is expected to come into force in countries in 1993. In the course of the last revisions, the traditional uses of the ICD have been expanded. Beyond the obvious epi- demiological uses, the classification is used nowadays for the planning and management of health services, the storage and retrieval of patient records, and in a wide variety of settings in medicine and public health. Compared with its predecessors, the Ninth Revision (ICD-9) presented many new features in its content and • Medical Officer, Development of Epidemiological and Health Statis- tical Services, World Health Organization, Geneva. quality as well as its structure, making it more flexible, up-to-date and also more adaptable to various purpose- oriented uses. However, already during the preparation of ICD-9 it became apparent that in the future only a family of classifications could meet the needs of the ever-increasing number and variety of professional groups in the health field, and satisfy the demands for uniform assessment of health problems for decision making in prevention, in provision of health care and in research on particular problems. In the build-up to the Tenth Revision a number of meet- ings have been held that evaluated the experience of countries in the use of ICD-9 and considered the direction the classification should take in the future. The prepara- tory meeting on ICD-10 held in 1983 dealt with the results of those meetings and recommended that the ICD-10 should follow the well-established pattern of ICD, but be developed as a core of a family of classifi- cations from which a series of modules could be derived, each reaching a different degree of specificity and ad- apted to a particular speciality or type of user. In order to facilitate the function of the future ICD as a core classification the first Expert Committee on ICD-10 held in San Francisco in 1984 decided to base the ICD on an alphanumeric coding scheme using an alphabetic character followed by two numbers at the basic level instead of the traditional code of three numbers. Further detail would still be provided by means of decimal num- eric subdivisions at the four-character level. The use of codes ranging from A00-299 would more than double the size of the coding frame compared with ICD-9 and would provide the space for the regular ICD chapters as well as for the two supplementary classifications of ICD-9 - External causes of injury and poisoning and Fac- tors influencing health status and contact with health services. As the contents of the ICD-10 will cover more than just categories of diseases, the Committee recom- mended that the title of ICD be amended to "International Statistical Classification of Diseases and Related Health Problems· but its abbreviation should still be "ICD". The family of disease and health-related classifications (Fig. 1) should include speciality-based adaptations (e.g. oncology, dentistry, etc.), where the chief difference lies in the further expansion of the ICD itself, and also clas- sifications such as for general medical practice where the difference lies more in condensation of categories and in giving emphasis to some less precise diagnostic termi- nology. Those speciality-based adaptations of ICD-10 should not amend the classification at the fourth-charac- ter level but only provide extension of detail at the fifth character and beyond. A further group of classifications would cover information not presented in the main ICD but having important medical or health implications (e.g. disabilities, handicaps, procedures in medicine and rea- sons for encounters). The ICD will be further supplemented by the International Nomenclature of Diseases (IND) which should be clearly distinguished from the ICD. The ICD is particularly de- signed for the recording and reporting of morbidity and Rapp. trimest. statist. sanit. mond .. 41 ( 19881 - 33 - FIG.1 SCHEMA FOR A FAMILY OF DISEASE AND HEALTH-RELATED CLASSIFICATIONS INTERNATIONAL STATISTICAL CLASSIFICATION OF DISEASES AND RELATED HEAL TH PROBLEMS INFORMATION SUPPORT TO ICD 3-CHARACTER CORE SPECIALITY-BASED PRIMARY HEAL TH CARE Diagnoses ADAPTATIONS Lay reporting Symptoms Oncology Community-based information <---- Impairments - Dentistry and stomatology for health Abnormal laboratory findings Ophthalmology (country- or community-based Injuries and poisonings Dermatology schemes) External factors influencing health Paediatrics status SHORT TABULATION LISTS OTHER HEALTH-RELATED CLASSIFICATIONS Disablement Procedures Reason for encounter mortality statistics, and for this purpose it groups dis- eases into categories; its primary concern is not the name that should be given to a disease, but the category under which an occurrence of the disease should be reported. The IND is a nomenclature, not a classification; it is a list of recommended names for all diseases, with no attempt to specify the manner in which those dis- eases should be classified for the purposes of statistical reporting. The difference between ICD and IND can be seen from the fact that ICD contains inclusion and exclu- sion notes as well as subcategories for other diseases of a particular organ or system which group but do not name the diseases. In August 1984 a first draft proposal for ICD-10 contain- ing three-character category titles only was circulated to WHO Member States, WHO collaborating centres for the classification of diseases, nongovernmental organi- zations (NGOs) in official relations with WHO, and other interested groups and individuals. The main purpose of that circulation was to obtain views on the proposed alphanumeric structure, the relative number of catego- ries provided for each chapter and the amount of space left for future expansions and revisions within chapters. The vast majority of replies supported the alphanumeric approach and were in agreement with the general direc- tion that the Tenth Revision was taking. While it was known that the alphanumeric scheme of the future ICD would cause some difficulties and increased costs, par- ticularly in computer processing, the advantages of the expanded coding frame were considered to outweigh the disadvantages. Wld hlth statist. quart .• 41 ( 1988) Otorhinolaryngology Neurology, etc. General medical practice ICD 4-CHARACTER LEVEL INTERNATIONAL NOMENCLA- TURE OF DISEASES (IND) The second draft proposal for ICD-10 containing both three- and four-character category titles was distributed in July 1986 in the same way as the first proposal. It incorporated comments received on the first draft pro- posal from countries; recommendations of the annual meetings of WHO collaborating centres for the classifi- cation of diseases; input from WHO divisions and units; and contributions from temporary advisers and other sources. The Second Expert Committee on ICD-10 held in Geneva from 23-27 November 1987 considered the updated draft proposal for ICD-10 at the three- and four- character levels with inclusion terms and exclusion notes, the revised mortality and morbidity coding rules and the definitions to be used with the Tenth Revision. The draft proposal for ICD-10 which was submitted to the Second Expert Committee for ICD-10 and which will, with further minor amendments, be presented to the International Conference on the Tenth Revision of ICD to be held in 1989, has been constructed so that the man- datory tabulations requested by WHO for international comparisons can be based exclusively on three-charac- ter categories. The dagger/asterisk system of dual clas- sification that was introduced at ICD-9 has been refined and extended. The asterisk classification is contained in homogeneous categories at the three-character level for ease of use and interpretation. The draft proposal for ICD-10, comprising 21 chapters, is outlined in the Annex and shows a different chapter arrangement to that of ICD-9. The two supplementary classifications of ICD-9 are included under the characters V, W, X, Y and Z. The - 34 - Tenth Revision of ICD has used (where available) the names of diseases recommended by IND and tries thus to promote the internationally-agreed nomenclature. The volumes of the IND that have been completed so far cover infectious and parasitic diseases as well as dis- eases of the lower respiratory tract. Those in prepara- tion now comprise diseases of the cardiovascular, digestive, nervous and female genital systems. In discussing the advantages and disadvantages of the ICD one has to bear in mind that: • the ICD is primarily an international standard statistical tool and thus subject to international agreement; • it has to serve many purposes in countries at different stages of economic development throughout the world; • it has to be applied by physicians educated at different medical schools, at different times and with different interests in the application of ICD; • it is faced on the one hand with sophisticated com- puter users and on the other hand still has to serve manual and summary uses - thus the ICD can be, at best, only a compromise. For the establishment of the family of classifications, WHO activities are planned as follows: Assistance and guidance in the development and revision of country-specific instruments facilitating data collection in the field of primary health care. Development of special tabulation lists on the basis of ICD-10 to be submitted to the International Con- ference for the Tenth Revision. Assistance to nongovernmental organizations and other international bodies producing adaptations and applications of ICD-10 for special purposes. Further consultation on the use and revision of the International Classification of Impairments, Disabili- ties and Handicaps (ICIDH) that was published for trial purposes by WHO in 1980. Further development of the IND in cooperation with the Council for International Organizations of Medical Sciences. Assistance to countries producing national-language versions of ICD-10. Familiarization and reorientation courses on the Tenth Revision of ICD to be organized at regional, intercountry and country level during 1991-1992 by WHO Regional Offices, WHO collaborating centres for the classification of diseases and countries. SUMMARY The International Classification of Diseases has, under various names, been for many decades the essential tool for national and international comparability in public health. This statistical tool has been customarily revised every 10 years in order to keep up with the advances of medi- cine. At first intended primarily for the classification of causes of death, its scope has been progressively wi- dening to include coding and tabulation of causes of morbidity as well as medical record indexing and retrie- val. The ability to exchange comparable data from region to region and from country to country, to allow compari- son from one population to another and to permit study of diseases over long periods, is one of the strengths of the International Statistical Classification of Diseases, Injuries, and Causes of Death (ICD). WHO has been responsible for the organization, coordi- nation and execution of activities related to ICD since 1948 (Sixth Revision of the ICD) and is now proceeding with the Tenth Revision. For the first time in its history the ICD will be based on an alphanumeric coding scheme and will have to function as a core classification from which a series of modules can be derived, each reaching a different degree of specificity and adapted to a particu- lar speciality or type of user. It is proposed that the chapters on external causes of injury and poisoning, and factors influencing health status and contact with health services, which were supplementary classifications in ICD-9, should form an integral part of ICD-10. The title of ICD has been amended to "International Statistical Clas- sification of Diseases and Related Health Problems'·, but the abbreviation "ICD" will be retained. The use of the codes ranging from AOO-Z99 doubles the size of the coding frame compared with ICD-9. The draft proposals for ICD-10 chapters at three- and four-character levels were distributed worldwide in 1984 and 1986 respec- tively and the comments received were incorporated in a draft proposal presented to the Second Expert Commit- tee on ICD-10 in November 1987. A slightly revised draft will be submitted to the Interna- tional Conference on the Tenth Revision scheduled for 1989. The Tenth Revision of ICD itself will come into use in countries in 1993. RESUME Classification statistique internationale des maladies et autres problemes de sante - Dixieme revision Bien que son titre ait varie plusieurs fois, la Classification internationale des maladies est depuis de nombreuses decennies !'instrument essentiel de comparaison des donnees nationales et internationales en sante publi- que. Cet instrument statistique est normalement revise tous les 10 ans pour tenir compte des progres de la medecine. Destine essentiellement au depart a fournir une classifi- cation des causes de deces, ii a peu a peu ete elargi pour servir au codage et a la mise en tableaux des caus~s de morbidite ainsi qu'a l'indexage des dossiers medicaux. La possibilite d'echanger des donnees comparables de region a region et de pays a pays, de faire des compa- raisons entre populations et d' etudier les maladies sur de longues periodes est l'une des forces de la Classification statistique internationale des maladies, traumatismes et causes de deces (CIM). L'OMS a pris en main !'organisation, la coordination et I' execution des activites interessant la CIM en 1948 (Sixieme revision de la CIM) et travaille actuellement a la Dixieme revision. Pour la premiere fois de son histoire, la CIM sera etablie d'apres un systeme de codage alpha- Rapp. trimest. statist. sanit. mond .. 41 (1988) - 35 - numerique et elle servira de classification de base dont pourront ~tre derives une serie de modules, chacun Visant Un degre de specificite different OU etant adapte a une specialite OU a un type d'utilisateurs donne. II est prevu que les chapitres « causes exterieures de trauma- tismes et empoisonnements» et «facteurs influant sur I' etat de sante et motifs de recours aux services de san- te », qui etaient des classifications supplementaires dans la CIM-9, fassent partie integrante de la CIM-10, dont ii a ete decide par ailleurs de modifier le titre (Classification statistique internationale des maladies et autres proble- mes de sante), tout en conservant !'abbreviation «CIM». La possibilite d'utiliser des codes allant AOO a Z99 dou- ble I' espace de codage par rapport a la CIM-9. Les avant- projets des chapitres de la CIM-10 a trois et a quatre caracteres ont.ete distribues dans le monde entier, res- pectivement en 1984 et 1986, et ii a ete tenu compte des observations rec;ues dans le texte propose au Deuxieme comite d'experts sur la CIM-10, en novembre 1987. Un texte legerement remanie sera soumis a la Confe- rence internationale sur la dixieme revision, prevue pour 1989, la Dixieme revision elle-m~me entrant en vigueur dans les pays en 1993. FIG.1 SCHEMA D'UNE ccFAMILLE•• DE CLASSIFICATION DES MALADIES ET AUTRES CLASSIFICATIONS SANITAIRES CONNEXES CLASSIFICATION ST A TISTIOUE INTERNATIONALE DES MALADIES ET AUTRES PROBLEMES OE SANTE APPUI INFORMATIONNEL AUX SOINS DE SANTE PRIMA IRES RUBRIOUES CIM OE BASE A 3 CARACTERES ADAPTATIONS PAR SPECIALITE Diagnostics Sympt6mes Oeficiences Oncologie Renseignements fournis par des non-medecins Informations pour la sante re- cueillies sur place Resultats laboratoire anormaux Traumatismes et empoisonne- Oentisterie et stomatologie Ophtalmologie Dermatologie Pediatrie O.R.l. ments (systemes a base nationale ou communautaire) Facteurs exterieurs influant sur r etat de sante Neurologie, etc. AUTRES CLASSIFICATIONS SANIT AIRES CONNEXES lncapacites Procedures Motifs de l'examen I LISTES ABREGEES POUR LA MISE EN TABLEAUX CIM RUBRIOUES A 4 CARACTERES Medecine generale NOMENCLATURE INTERN A TIONALE DES MALADIES (NIM) BIBLIOGRAPHY - BIBLIOGRAPHIE 1 . WORLD HEAL TH ORGANIZATION. Manual of the interna- tional classification of diseases, injuries and causes of death. Ninth Revision. Geneva, WHO, 1977. ORGANISATION MONDI ALE DE LA SANTE. Manuel de Ja clas- sification statistique internationale des maladies, traumatismes et causes de deces. Neuvieme revi- sion. Geneve, OMS, 1977. 2. WORLD HEAL TH ORGANIZATION. International classifica- tion of impairments, disabilities and handicaps. Geneva, WHO, 1980. ORGANISATION MONDI ALE DE LA SANTE. Classification in- ternationale des deficiences, incapacites et handi- caps. OMS/INSERM, 1981. 3. COUNCIL FOR INTERNATIONAL ORGANIZATIONS OF MEDICAL SCIENCES. International nomenclature of diseases. Vol. /I-infectious diseases. Geneva, CIOMS, 1982. Wldhlthstatist. quan.,41 (19881 4. KUPKA, K. International Classification of Diseases: Ninth Revision. WHO Chronicle, 32: 219-225 (1978). KUPKA, K. Classification internationale des maladies: neuvieme revision. Chronique OMS, 32: 235-242 (1978). 5. WORLD HEALTH ORGANIZATION. Report of the Expert Committee on the International Classification of Dis- eases. Second meeting on the Tenth Revision. (Document WHO/DES/EC/ICD-10/87.38, 1987). 6. ISRAEL, A.A. The International Classification of Disea- ses: two hundred years of development. Public health reports, 93 (2): 150-152 (1978). 7. MANUILA, A. Progress in medical terminology. Basel/Munich/Paris/London/New York/Sydney, S. Karger, 1981. Chapters I II Ill IV v VI VII VIII IX x XI XII XIII XIV xv XVI XVII XVIII XIX xx XXI Chapitres I II Ill IV v VI VII VIII IX x XI XII XIII XIV xv XVI XVII XVIII XIX xx XXI - 36 - ANNEX - ANNEXE Outline of ICD-10 Certain infectious and parasitic diseases Neoplasms Diseases of the blood and blood-forming organs, and certain disorders involving the immune mechanisms Endocrine, nutritional and metabolic diseases Mental, behavioural and developmental disorders Diseases of the nervous system Diseases of the eye and adnexa Diseases of the ear Diseases of the circulatory system Diseases of the respiratory system Diseases of the digestive system Diseases of the skin and subcutaneous tissue Diseases of the musculoskeletal system and connective tissue Diseases of the genitourinary system Pregnancy, childbirth and the puerperium Certain conditions originating in the perinatal period Congenital malformations, deformations, and chromosomal abnormalities Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified Injury, poisoning and certain other consequences of external causes External causes of morbidity and mortality Factors influencing health status and contact with health services Plan de la CIM-10 Certaines maladies infectieuses et parasitaires Tumeurs Maladies du sang et des organes hematopoi"etiques et certains troubles du mecanisme immunitaire Maladies endocriniennes, de la nutrition et du metabolisme Troubles mentaux et troubles du comportement et du developpement Maladies du systeme nerveux Maladies de I' reil et de ses annexes Maladies de l'oreille Maladies de l'appareil circulatoire Maladies de I' appareil respiratoire Maladies de I' appareil digestif Maladies de la peau et du tissu cellulaire sous-cutane Maladies du systeme osteo-articulaire, des muscles et du tissu conjonctif Maladies des organes genito-urinaires Grossesse, accouchement et suites de couches Certaines affections dont l'origine se situe dans la periode perinatale Malformations et deformations congenitales et aberrations chromosomiques Symptomes, signes et resultats anormaux des examens cliniques et des analyses de laboratoire, non classes ailleurs Lesions traumatiques, empoisonnements et certains autres effets dus a des causes externes Causes externes de morbidite et de mortalite Facteurs qui influencent l'etat de sante et le contact avec les services de sante Range of codes AOO-A99, 800-899 COO-C99, 000-049 050-099 EOO-E99 FOO-F99 GOO-G99 HOO-H59 H60-H99 100-199 JOO-J99 KOO-K99 LOO-L99 MOO-M99 NOO-N99 000-099 POO-P99 Q00-099 ROO-R99 SOO-S99, TOO-T99 VOO-V99, WOO-W99, XOO-X99, YOO-Y99 ZOO-Z99 Codes correspondants AOO-A99, 800-899 COO-C99, 000-049 050-099 EOO-E99 FOO-F99 GOO-G99 HOO-H59 H60-H99 100-199 JOO-J99 KOO-K99 LOO-L99 MOO-M99 NOO-N99 000-099 POO-P99 Q00-099 ROO-R99 SOO-S99, TOO-T99 VOO-V99, WOO-W99 XOO-X99, YOO-Y99 ZOO-Z99 Rapp. trimest. statist. sanit. mond., 41 (1988)