MEDINFO 2001 V. Patel et al. (Eds) Amsterdam: IOS Press © 2001 IMIA. All rights reserved
A Survey to Identify the Clinical Coding and Classification Systems Currently in Use Across Europe Simon de Lusignana, Christopher Minmaghb, John Kennedyc, Marco Zeimetd, Hans Bommezijne, John Bryantf a
b
General Practice, St George's Hospital Medical School, London, England Information Technology Lead Kirkby Primary Care Group. Merseyside, England c North Lincolnshire Primary Care Group, South Humber, England d Projet de Rechere en Nursing, Clinique Ste Thérèse, Luxembourg e Dutch Army Headquarters, Holland f EHIMS, University Surrey, Guildford, England
modifications to coding and classification systems, as this practice risks significantly slowing progress towards easy transfer of records between computer systems.
Abstract Introduction: This is a survey to identify what clinical coding systems are currently in use across the European Union, and the states seeking membership to it. We sought to identify what systems are currently used and to what extent they were subject to local adaptation.
Keywords: Coding, Classification, Computerised Medical Record, Standards.
Introduction
Background: Clinical coding should facilitate identifying key medical events in a computerised medical record, and aggregating information across groups of records. The emerging new driver is as the enabler of the life-long computerised medical record. A prerequisite for this level of functionality is the transfer of information between different computer systems. This transfer can be facilitated either by working on the interoperability problems between disparate systems or by harmonising the underlying data. This paper examines the extent to which the latter has occurred across Europe.
This paper examines what clinical coding and classification systems are currently in use across the EU (European Union) including those countries intending to join. What classification systems are in use is an important issue as computerised medical records are being created across Europe. All incorporate some system form of clinical coding [1]. These computerised record systems are migrating from being medical records within single institutions to become the life-long health records. The latter requires components of the new record to be at worse compatible, but at best fully integrated, the need for which has been articulated for some time [2]. This can either be achieved through the adoption of a single coding system or from developing mechanisms for effectively mapping from one system to another. The first step towards achieving integration is to documents what clinical coding and classification systems are in place at present.
Method: Literature and Internet search. Requests for information via electronic mail to pan-European mailing lists of health informatics professionals. Results: Coding systems are now a de facto part of health information systems across Europe. There are relatively few coding systems in existence across Europe. ICD9 and ICD 10, ICPC and Read were the most established. However the local adaptation of these classification systems either on a by country or by computer software manufacturer basis; significantly reduces the ability for the meaning coded with patients computer records to be easily transferred from one medical record system to another.
Here not only is how many different classifications in use recorded but also evidence of local adaptations had been sought. The latter is of critical importance as it can seriously undermine the progress towards delivering an integrated health record. It can create the illusion of sameness, whilst hiding the reality of incompatibility. The importance of this practice and it long term negative influence on compatibility is highlighted within this survey [3].
Conclusions: There is no longer any debate as to whether a coding or classification system should be used. Convergence of different classifications systems should be encouraged. Countries and computer manufacturers within the EU should be encouraged to stop making local
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search engine [9] were searched for entries on coding classification and standards.
Background The following are the major coding and classification systems in use in Europe:
Centres for Coding and Classification An Internet based search using standard web-based searchengines (Google, Alltheweb, Metager and Infind) for national and pan-European standards bodies, professional organisations and coding and classification centres was undertaken. The key words again were coding classification and standards.
ICD-10 The International Classification of Diseases (ICD) was developed within the WHO (World Health Organisation. It provides a uniform classification scheme for diseases, injuries, impairments, symptoms, and causes of death, with a stated purpose to become "an International Classification of Disease, Disorders, and Health Problems." This continuing extension of what can be termed as disease, or what needs classifying, results in part from the growing demand for medical information.
e-mail survey Triangulation of the methodology was achieved by contacting health informatics experts, governmental bodies and primary care physicians across Europe by e-mail. This was targeted on countries where we had no, or only a single source of information. They were asked to identify the coding and classification systems in use in their country, to report any local adaptations or variations and of other experts, web or literature resources that we should consider.
ICD-10 [4] is the Tenth Revision of the ICD or International Statistical Classification of Diseases and Related Health Problems, to give its full title. It is the latest in a series that was formalised as long ago as 1893 as the Bertillon Classification or International List of Causes of Death. The familiar abbreviation "ICD" has been retained even though it now represents a much broader classification.
Results Literature review
ICPC
Our review found a large number of hits, but these largely related to comparisons of coding and classification system and were about their taxonomy and ontology. No geographical analysis was found. Papers about comparisons with SNOMED (Systematized Nomenclature in Medicine,) UMLS (Unified Medical Language System,) and Read systems dominated the literature [10].
The International Classification of Primary Care, ICPC, produced by WONCA, was developed in Holland and first published in 1987 [5]. A second edition, ICPC211, appeared in 1997 and an extension, ICPC2-PLUS in 1998, there is a more recent still electronic version [6]. ICPC2-PLUS uses a traditional bi-axial structure with seventeen chapters on one axis, and seven components on the other. An initial single alphabetical character indicates membership of a particular chapter and two numerals then identify components (such as symptoms, test results, administration). In the ever-changing health care environment, this so-called mnemonic approach lacks flexibility, a problem that may not be outweighed by the computational simplicity it affords. The scheme is not concept-based.
Centres for classification and coding Standards organisations were identified for eleven European states. None of these gave a clear indication of what clinical coding systems were in use. Their web addresses are set out in Table 1. Professional bodies were identified within a majority of EU countries, and these were examined for any links related to clinical coding, including training courses. Ten coding and classification centres were identified. There was no comprehensive list by country of what coding system, or local variation to it on any of these.
Read Read Codes are used in the UK. They are arranged as a sub-type hierarchy and include clinical findings (disorders, history, observations), interventions, administration, and additional terms such as occupations, anatomy and drugs. Although primarily intended for use by clinicians in individual patient electronic health care records, crossmapping tables to other classifications (such as ICD1010) are provided to allow collection of aggregate data for population studies [7},[8].
e-mail survey This was sent out to eight target countries, as well as to one general mailing list. Responses were received from all but two countries. Which coding systems are used in which states? The complexity of the coding schemes used across Europe and the extent of their local modification are our principle findings.
Method Information about the coding systems in use was sought from three sources.
The predominant coding systems used in the countries studied are set out below in table 2. Only countries for which we have complete data are listed. They break down into three groups:
Literature review Existing literature knowledge bases, Pub-Med Medline and JAMIA (Journal of the American Informatics Association)
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1.
this is occurring and to try to develop strategies to overcome the practice.
Countries using ICD-10 in secondary and ICPC in primary care,
2. Countries using ICD-10 in both primary and secondary
Table 2 - The predominant Coding and Classification system used in European nations
care, and lastly
3. One country that uses ICD-10 and OPCS-4 (Office of Population, Censuses and Surveys - Classification of Surgical Operations and Procedures - 4th Revision [11]) in secondary care, and uses the Read Codes in primary care.
Coding/Classification system ICD-10 in secondary Care ICPC in primary Care
Table 1 - European and National Standard bodies
ICD-10 in both secondary and primary care ICD-10 and OPCS-4 in secondary care and Read codes in primary care
Standards Organisations CEN
URL http://www.cenorm.be/
Comite Europeen de Normalisation
EHTO European Health Telematics Observatory
Austrian Standard Institute Belgium Croatia Denmark Finland standards France standards German Standards Iceland Italian Norwegian Standards
http://www.ehto.org/ Look for links to CEN 251
Country Belgium - Denmark - France - Greece - Italy - Netherlands - Norway - Portugal - Spain Austria (also ICD-9) Germany United Kingdom
Table 3 - Countries with incomplete or contradictory data for their predominant coding system
http://www.onnorm.at/index.html http://www.ibn.be/ http://www.dznm.hr/
Coding/Classification system ICD-10 listed for secondary care, incomplete data for primary care
http://www.ds.dk/default.stm
http://www.sfs.fi/ http://www.afnor.fr/ http://www.din.de/ http://www.stri.is/ http://www.unicei.it http://www.standard.no/
ICPC for primary care, no data for secondary care
Country Czech - Finland - Iceland Ireland - Luxembourg Macedonia - Malta - Poland Rumania - Sweden Switzerland (also ICD9-CM for procedures) Croatia
There also appears to be a division between the English and non-English speaking parts of Europe, with the UK moving down the Read Code/SNOMED CT (SNOMED Clinical Terms [12]) route while the rest of Europe remains with ICD 9 and 10 and ICPC. This said the SNOMED web-site lists 13 European countries as users (Austria, Belgium, Finland, France, Germany, Greece, Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and UK.) Further demonstrating the complexity of the current situation.
Additional data is still being collected and will be added. Multiple local variations of the coding schemes were also identified. For many countries we only know the predominant system used in one part of the health system. This incomplete data is set out in Table 3. These countries fall into two groups, the first are countries using ICD-10 in secondary care but for whom we have either no, or conflicting information as to what is used in primary care. One county uses ICPC in primary care, but we have no data as yet as to what is used in secondary care.
Previous research has set out to highlight these differences and to looked to generate a standardisation framework [13]. However there is as yet no objective indication that work had significantly progressed in this area.
Discussion ICD-10 and ICPC are the principle coding systems in use within Europe. Although there are very few clinical coding and classification systems in use, local adaptation is widespread. This ranges from the addition of local codes, to amalgamation of other coding systems for drugs, procedures or codes within specific disease areas. Sometimes when this is done, whole chapters of the base coding system are removed.
Primarily different coding and classification systems arose for different purposes. Read, SNOMED and ICPC for recording clinical events in electronic records, ICD-9, ICD10 and the OPCS-4 codes for collecting aggregated data on health outcomes and activity. Others have arisen for billing purposes e.g. ICD-9CM and TarMed (Medical Tariff system [14].) However a whole raft of adaptations has been identified that seek to expand the utilisation of these codes into new areas.
This phenomenon of local adaptation needs to be documented more systematically and in more detail that in our study, although we have found sufficient evidence to show how widespread the practice is. Further research should be directed to developing an understanding of why
HL7 (Health Level 7 [15]) has been established, to try to ensure interoperability between different systems, and in messaging. The need for such an organisation merely reflects amongst other things the parlous state of the coding
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dynamic clinical JAMIA 1997 Nov-Dec;4(6):465-72
and classification systems within the different systems. Whilst this work is to be applauded, working to standardise the coding and classification systems also has a contribution to make.
vocabulary.
[9] Journal of the American Informatics Association. URL: http://www.jamia.org
Conclusion
[10] Campbell JR, Carpenter P, Sneiderman C et al. Phase II Evaluation of Clinical Coding Schemes: Completemess, Taxonomy, Mapping Definitions and Clarity. JAMIA 1997;4:238-51.
Development of multiple systems for the coding and classification of clinical information cannot be worthwhile, unless the situation thus far is merely regarded as an opportunity to pilot different methodologies. To continue with different coding systems must be regarded as wasteful, as it can only add costs to already over-burdened health systems. It will only make more difficult links to social care and other bodies with which medical records must eventually integrate appropriate information.
[11] NHS Information Authority. OPCS-4 (Office of Population, Censuses and Surveys - Classification of Surgical Operations and Procedures - 4th Revision) http://www.coding.nhsia.nhs.uk/clin_class/opcs_4.asp [12] SNOMED CT (Clinical Terms). URL: http://www.snomed.org/snomedct_txt.html#docs
It cannot be in the interests of individuals and families able to move freely within the boundaries of the EU, that their computerised health record may only have meaning on the system that created it. This may be either because it is structured using a local corruption of an international system or using a classification not used in their current location. Consensus should be sought to reduce the differences between the systems, with the long term goal of eventual amalgamation.
[13] SESAME Project Standardization in Europe on Semantical Aspects of Medicine. University of Nijmegen, Medical Informatics, Epidemiology and Statistics 1995 URL: http://www.ehm.kun.nl/mi/project/sesame/summary.ht m#Abstract
Acknowledgements
[14] TarMed (Medical Tariffs) Swiss Medical Association. FMH. URL: http://www.fmh.ch (Use the search engine - search term TarMed .)
Jos Aarts of Erasmus University, Rotterdam, Holland, for his helpful comments on the research idea and the paper as it was being developed.
[15] HL7 (Health Level 7) an ANSI (American National Standard Institute) standards developing organisation. URL: www.hl7.org
References
Address for Correspondence: Dr Simon de Lusignan Primary Care Informatics General Practice and Primary Care Hunter Wing St George’s Hospital Medical School LONDON SW17 ORE Tel: ++44 (0)20 8725 5661 Fax: ++44(0)20 8767 7697
[email protected]
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