Medical classification
Encyclopedia
Medical classification, or medical coding, is the process of transforming descriptions of medical diagnoses
and procedures
into universal medical code numbers. The diagnoses and procedures are usually taken from a variety of sources within the health care
record, such as the transcription of the physician's notes, laboratory results, radiologic results, and other sources.
Diagnosis codes
are used to track disease
s and other health conditions, whether they are chronic diseases such as diabetes mellitus
and heart disease
, to contagious diseases such as norovirus, the flu, and athlete's foot
. These diagnosis and procedure codes are used by government health programs, private health insurance companies, workers' compensation carriers and others.
Medical classification systems are used for a variety of applications in medicine
, public health
and medical informatics, including:
A statistical classification brings together similar clinical concepts and groups them into categories. The number of categories is limited so that the classification does not become too big. An example of this is the International Statistical Classification of Diseases and Related Health Problems (known as ICD). It groups diseases of the circulatory system into one "chapter" (known as Chapter IX
, covering codes I00–I99). Within this chaper, there is for instance, code I47.1. The code title (rubric
) is Supraventricular tachycardia. However, there are several other clinical concepts that are also classified here. Amongst them are paroxysmal atrial tachycardia, paroxysmal junctional tachycardia, auricular tachycardia and nodal tachycardia.
Another feature of statistical classifications is the provision of residual categories for "other" and "unspecified" conditions that do not have a specific category in the particular classification.
In a nomenclature
there is a separate listing and code for every clinical concept. So, in the previous example, each of the tachycardia listed would have its own code. This makes nomenclatures unwieldy for compiling health statistics.
Types of coding systems specific to health care include:
(WHO) maintains several internationally endorsed classifications designed to facilitate the comparison of health related data within and across populations and over time as well as the compilation of nationally consistent data. This "Family of International Classifications" (FIC) include three main (or reference) classifications on basic parameters of health
prepared by the organization and approved by the World Health Assembly
for international use, as well as a number of derived and related classifications providing additional details. Some of these international standards have been revised and adapted by countries for national use.
s, disorders, symptoms and medical signs. In addition to the ICD
and its national variants, they include:
. In addition to the ICHI
and ICPC
, they include:
Library classification
Medical diagnosis
Medical diagnosis refers both to the process of attempting to determine or identify a possible disease or disorder , and to the opinion reached by this process...
and procedures
Medical procedure
A medical procedure is a course of action intended to achieve a result in the care of persons with health problems.A medical procedure with the intention of determining, measuring or diagnosing a patient condition or parameter is also called a medical test...
into universal medical code numbers. The diagnoses and procedures are usually taken from a variety of sources within the health care
Health care
Health care is the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments in humans. Health care is delivered by practitioners in medicine, chiropractic, dentistry, nursing, pharmacy, allied health, and other care providers...
record, such as the transcription of the physician's notes, laboratory results, radiologic results, and other sources.
Diagnosis codes
Diagnosis codes
In healthcare, diagnostic codes are used to group and identify diseases, disorders, symptoms, human response patterns, and medical signs, and are used to measure morbidity and mortality...
are used to track disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s and other health conditions, whether they are chronic diseases such as diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
and heart disease
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, to contagious diseases such as norovirus, the flu, and athlete's foot
Athlete's foot
Athlete's foot is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas. It is caused by fungi in the genus Trichophyton and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses...
. These diagnosis and procedure codes are used by government health programs, private health insurance companies, workers' compensation carriers and others.
Medical classification systems are used for a variety of applications in medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, public health
Public health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
and medical informatics, including:
- statistical analysis of diseases and therapeutic actions
- reimbursement; e.g., based on diagnosis-related groupDiagnosis-related groupDiagnosis-related group is a system to classify hospital cases into one of originally 467 groups. The 467th was "Ungroupable." The system of classification was developed as a collaborative project by Robert B Fetter, PhD of the Yale School of Management, and John D Thompson, MPH of the Yale...
s - knowledge-based and decision support systemDecision support systemA decision support system is a computer-based information system that supports business or organizational decision-making activities. DSSs serve the management, operations, and planning levels of an organization and help to make decisions, which may be rapidly changing and not easily specified in...
s - direct surveillance of epidemic or pandemic outbreaks
Classification types
There are many different medical classifications, but they fall into two main groupings: Statistical classifications and Nomenclatures.A statistical classification brings together similar clinical concepts and groups them into categories. The number of categories is limited so that the classification does not become too big. An example of this is the International Statistical Classification of Diseases and Related Health Problems (known as ICD). It groups diseases of the circulatory system into one "chapter" (known as Chapter IX
ICD-10 Chapter IX: Diseases of the circulatory system
- Acute rheumatic fever :* Rheumatic fever without mention of heart involvement* Rheumatic fever with heart involvement** Acute rheumatic pericarditis** Acute rheumatic endocarditis ** Acute rheumatic myocarditis...
, covering codes I00–I99). Within this chaper, there is for instance, code I47.1. The code title (rubric
Rubric
A rubric is a word or section of text which is traditionally written or printed in red ink to highlight it. The word derives from the , meaning red ochre or red chalk, and originates in Medieval illuminated manuscripts from the 13th century or earlier...
) is Supraventricular tachycardia. However, there are several other clinical concepts that are also classified here. Amongst them are paroxysmal atrial tachycardia, paroxysmal junctional tachycardia, auricular tachycardia and nodal tachycardia.
Another feature of statistical classifications is the provision of residual categories for "other" and "unspecified" conditions that do not have a specific category in the particular classification.
In a nomenclature
Medical terminology
Medical terminology is a vocabulary for accurately describing the human body and associated components, conditions, processes and process in a science-based manner. Some examples are: R.I.C.E., trapezius, and latissimus dorsi. It is to be used in the medical and nursing fields...
there is a separate listing and code for every clinical concept. So, in the previous example, each of the tachycardia listed would have its own code. This makes nomenclatures unwieldy for compiling health statistics.
Types of coding systems specific to health care include:
- Diagnostic codesDiagnosis codesIn healthcare, diagnostic codes are used to group and identify diseases, disorders, symptoms, human response patterns, and medical signs, and are used to measure morbidity and mortality...
- Procedural codesProcedure codesProcedure codes are numbers or alphanumeric codes used to identify specific health interventions taken by medical professionals.-International:...
- Pharmaceutical codesPharmaceutical codesPharmaceutical codes are used in medical classification to uniquely identify medication. Examples of coding systems include:* Anatomical Therapeutic Chemical Classification System -- administered by World Health Organization...
- Topographical codesTopographical codesIn medicine, "topographical codes" are codes that indicate a specific location in the body.-Examples:Only the first of these is a system dedicated only to topography. The others are more generalized systems that contain topographic axes.* Nomina Anatomica * ICD-O* SNOMED* MeSH...
WHO Family of International Classifications
The World Health OrganizationWorld Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
(WHO) maintains several internationally endorsed classifications designed to facilitate the comparison of health related data within and across populations and over time as well as the compilation of nationally consistent data. This "Family of International Classifications" (FIC) include three main (or reference) classifications on basic parameters of health
Health
Health is the level of functional or metabolic efficiency of a living being. In humans, it is the general condition of a person's mind, body and spirit, usually meaning to be free from illness, injury or pain...
prepared by the organization and approved by the World Health Assembly
World Health Assembly
The World Health Assembly is the forum through which the World Health Organization is governed by its 194 member states. It is the world's highest health policy setting body and is composed of health ministers from member states....
for international use, as well as a number of derived and related classifications providing additional details. Some of these international standards have been revised and adapted by countries for national use.
Reference classifications
- International Statistical Classification of Diseases and Related Health ProblemsICDThe International Statistical Classification of Diseases and Related Health Problems is a medical classification that provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or disease...
(ICD)- ICD-9 (9th revision, published in 1977)
- ICD-9-CM (Clinical Modification, used in the US)
- ICD-10ICD-10The International Statistical Classification of Diseases and Related Health Problems, 10th Revision is a medical classification list for the coding of diseases, signs and symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or diseases, as maintained by the...
(10th revision, in use by WHO since 1994)- ICD-10-CM (Clinical Modification, used in the US)
- ICD-10-PCS (Procedure Coding System, used in the US)
- ICD-10-CA (used for morbidity classification in Canada).
- ICD-10-AM (used in Australia and New Zealand)
- EUROCAT - an extension of the ICD-10 Q chapter for congenital disorders
- ICD-9 (9th revision, published in 1977)
- International Classification of Functioning, Disability and HealthInternational Classification of Functioning, Disability and HealthInternational Classification of Functioning, Disability and Health, also known as ICF, is a classification of the health components of functioning and disability....
(ICF) - International Classification of Health InterventionsInternational Classification of Health InterventionsThe International Classification of Health Interventions is a system of classifying procedure codes being developed by the World Health Organization...
(ICHI) (previously known as International Classification of Procedures in Medicine)
Derived classifications
Derived classifications are based on the WHO reference classifications (i.e. ICD and ICF). They include:- International Classification of Diseases for OncologyInternational Classification of Diseases for OncologyThe International Classification of Diseases for Oncology is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by cancer registries.It is currently in its third revision ....
, Third Edition (ICD-O-3) - ICD-10 for Mental and Behavioural Disorders
- Application of the International Classification of Diseases to Dentistry and Stomatology, 3rd Edition (ICD-DA)
- Application of the International Classification of Diseases to Neurology (ICD-10-NA)
Related classifications
Related classifications in the WHO-FIC are those that partially refer to the reference classifications, e.g. only at specific levels. They include:- International Classification of Primary CareInternational Classification of Primary CareThe International Classification of Primary Care is a classification method for primary care encounters. It allows for the classification of the patient’s reason for encounter , the problems/diagnosis managed, primary or general health care interventions, and the ordering of the data of the...
(ICPC)- ICPC-2 PLUSICPC-2 PLUSICPC-2 PLUS is an extended terminology classified to ICPC-2 International Classification of Primary Care, which aids data entry, retrieval and analysis. ICPC-2 PLUS takes into account the frequency distribution of problems seen in primary health care...
- ICPC-2 PLUS
- International Classification of External Causes of Injury (ICECI)
- Anatomical Therapeutic Chemical Classification SystemAnatomical Therapeutic Chemical Classification SystemThe Anatomical Therapeutic Chemical Classification System is used for the classification of drugs. It is controlled by the WHO Collaborating Centre for Drug Statistics Methodology , and was first published in 1976....
with Defined Daily Doses (ATC/DDD) - Technical aids for persons with disabilities: Classification and terminology (ISO9999)
- International Classification for Nursing Practice (ICNP)
Diagnosis
The categories in a diagnosis classification classify diseaseDisease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s, disorders, symptoms and medical signs. In addition to the ICD
ICD
The International Statistical Classification of Diseases and Related Health Problems is a medical classification that provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances, and external causes of injury or disease...
and its national variants, they include:
- Diagnostic and Statistical Manual of Mental DisordersDiagnostic and Statistical Manual of Mental DisordersThe Diagnostic and Statistical Manual of Mental Disorders is published by the American Psychiatric Association and provides a common language and standard criteria for the classification of mental disorders...
(DSM)- DSM-IV CodesDSM-IV CodesDiagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, also known as DSM-IV-TR, is a manual published by the American Psychiatric Association that includes all currently recognized mental health disorders...
- DSM-IV Codes
- International Classification of Headache Disorders 2nd Edition (ICHD-II)
- International Classification of Sleep DisordersInternational Classification of Sleep DisordersThe International Classification of Sleep Disorders is "a primary diagnostic, epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine."...
(ICSD) - Online Mendelian Inheritance in Man, database of genetic codes
- Read codesRead codesRead codes are the standard clinical terminology system used in General Practice in the United Kingdom. It supports detailed clinical encoding of multiple patient phenomena including: occupation; social circumstances; ethnicity and religion; clinical signs, symptoms and observations; laboratory...
- Systematized Nomenclature of Medicine - Clinical TermsSNOMED CTSNOMED CT , is a systematically organised computer processable collection of medical terminology covering most areas of clinical information such as diseases, findings, procedures, microorganisms, substances, etc...
(SNoMed-CT)
Procedure
The categories in a procedure classification classify specific health interventions undertaken by health professionalsHealth care provider
A health care provider is an individual or an institution that provides preventive, curative, promotional or rehabilitative health care services in a systematic way to individuals, families or communities....
. In addition to the ICHI
International Classification of Health Interventions
The International Classification of Health Interventions is a system of classifying procedure codes being developed by the World Health Organization...
and ICPC
International Classification of Primary Care
The International Classification of Primary Care is a classification method for primary care encounters. It allows for the classification of the patient’s reason for encounter , the problems/diagnosis managed, primary or general health care interventions, and the ordering of the data of the...
, they include:
- Australian Classification of Health Interventions (ACHI)
- Canadian Classification of Health InterventionsCCICCI can refer to the year 201, in Roman numerals, and it is also a three-letter acronym that stands for:*Canadian Conservation Institute, a Canadian government conservation agency*CCI, the IATA identifier for Capital Cargo International Airlines...
- Current Procedural TerminologyCurrent Procedural TerminologyThe Current Procedural Terminology code set is maintained by the American Medical Association through the CPT Editorial Panel. The CPT code set describes medical, surgical, and diagnostic services and is designed to communicate uniform information about medical services and procedures among...
(CPT) - Health Care Procedure Coding System (HCPCS)
- ICD-10 Procedure Coding SystemICD-10 Procedure Coding SystemThe ICD-10 Procedure Coding System is an American system of medical classification used for procedural codes. The National Center for Health Statistics received permission from the World Health Organization to create the ICD-10-PCS as a successor to Volume 3 of ICD-9-CM and a...
(ICD-10-PCS) - Office of Population, Censuses and Surveys Classification of Surgical Operations and Procedures (OPCS-4)
- Australian Classification of Health Interventions (ACHI)
Other
- Classification of Pharmaco-Therapeutic ReferralsClassification of Pharmaco-Therapeutic ReferralsThe Classification of Pharmaco-Therapeutic Referrals is a taxonomy focused to define and group together situations requiring a referral from pharmacists to physicians regarding the pharmacotherapy used by the patients. It has been published in 2008...
(CPR) - Logical Observation Identifiers Names and CodesLOINCLogical Observation Identifiers Names and Codes is a database and universal standard for identifying medical laboratory observations. It was developed and is maintained by the Regenstrief Institute, a US non-profit medical research organization, in 1994...
(LOINC), standard for identifying medical laboratory observations - Medical Dictionary for Regulatory Activities (MedDRA)
- Medical Subject HeadingsMedical Subject HeadingsMedical Subject Headings is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences; it can also serve as a thesaurus that facilitates searching...
(MeSH) - Nursing Interventions ClassificationNursing Interventions ClassificationThe Nursing Interventions Classification is a care classification system which describes the activities that nurses perform as a part of the planning phase of the nursing process associate with the creation of a nursing care plan. The NIC consists of a standardized list which contains 433...
(NIC) - Nursing Outcomes ClassificationNursing Outcomes ClassificationThe Nursing Outcomes Classification is a classification system which describes patient outcomes sensitive to nursing intervention. The NOC is a system to evaluate the effects of nursing care as a part of the nursing process...
(NOC) - TIME-ITEMTIME-ITEMTIME-ITEM is an ontology of Topics that describes the content of undergraduate medical education. TIME is an acronym for "Topics for Indexing Medical Education"; ITEM is an acronym for "Index de thèmes pour l’éducation médicale." Version 1.0 of the taxonomy has been released and the web...
, ontology of topics in medical education - TNM Classification of Malignant Tumors
- Unified Medical Language SystemUnified Medical Language SystemThe Unified Medical Language System is a compendium of many controlled vocabularies in the biomedical sciences . It provides a mapping structure among these vocabularies and thus allows one to translate among the various terminology systems; it may also be viewed as a comprehensive thesaurus and...
(UMLS) - Victoria Ambulatory Coding System (VACS) / Queensland Ambulatory Coding System (QACS), Australia
Library classificationLibrary classificationA library classification is a system of coding and organizing documents or library materials according to their subject and allocating a call number to that information resource...
that have medical components
- Dewey Decimal System and Universal Decimal ClassificationUniversal Decimal ClassificationThe Universal Decimal Classification is a system of library classification developed by the Belgian bibliographers Paul Otlet and Henri La Fontaine at the end of the 19th century. It is based on the Dewey Decimal Classification, but uses auxiliary signs to indicate various special aspects of a...
(section 610–620) - National Library of Medicine classificationNational Library of Medicine classificationThe National Library of Medicine classification system is a library indexing system covering the fields of medicine and preclinical basic sciences. The NLM classification is patterned after the Library of Congress Classification system: alphabetical letters denote broad subject categories which...
See also
- Acronyms in healthcareAcronyms in healthcareThe following is a partial list of acronyms commonly used in health care. The terms listed are used within the health care systems of various countries.- A :*A&E Accident and Emergency Department...
- Ambulatory Payment Classification, US billing system for outpatient services
- Biological databaseBiological databaseBiological databases are libraries of life sciences information, collected from scientific experiments, published literature, high-throughput experiment technology, and computational analyses. They contain information from research areas including genomics, proteomics, metabolomics, microarray...
- Classification of mental disordersClassification of mental disordersThe classification of mental disorders, also known as psychiatric nosology or taxonomy, is a key aspect of psychiatry and other mental health professions and an important issue for consumers and providers of mental health services...
- Clinical coderClinical coderA clinical coder – also known as diagnostic coder, medical coder or medical records technician – is a health care professional whose main duties are to analyse clinical statements and assign standard codes using a classification system...
- Health information managementHealth Information ManagementHealth information management is the practice of maintenance and care of health records by traditional and electronic means in hospitals, physician's office clinics, health departments, health insurance companies, and other facilities that provide health care or maintenance of health records...
- Health informaticsHealth informatics.Health informatics is a discipline at the intersection of information science, computer science, and health care...
- Human resources for health information systemHRHISA “Human Resource for Health Information System” — also known within the health care sector as “human resource information system” — is a system for collecting, processing, managing and disseminating data and information on human resource for health...
- List of international common standards
- Medical dictionaryMedical dictionaryA medical dictionary is a lexicon for words used in medicine. The three major English language medical dictionaries are Stedman's, Taber's, and Dorland's Pocket Medical Dictionary. Other significant medical dictionaries are distributed by Elsevier, the world's largest publisher of medical and...
- North American Nursing Diagnosis AssociationNANDANANDA International is a professional organization of nurses standardized nursing terminology that was officially founded in 1982 and develops, researches, disseminates and refines the nomenclature, criteria, and taxonomy of nursing diagnoses...
(professional organization) - Nosology