Medical classification

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 medical record, such as the transcription of the doctor's notes, laboratory results, radiologic results, and other sources. Diagnosis codes are used to track diseases, whether they are everyday 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 and medical informatics


 * statistical analysis of diseases and therapeutic actions
 * reimbursement, e.g. based on DRGs
 * knowledge-based and decision support systems
 * direct surveillance of epidemic or pandemic outbreaks

Types of classification

 * Diagnostic codes
 * Procedural codes
 * Pharmaceutical codes
 * Topographical codes

Reference Classifications

 * International Statistical Classification of Diseases and Related Health Problems (ICD, includes ICD9 and ICD9-CM, currently used in US)
 * International Classification of Functioning, Disability, and Health (ICF)
 * International Classification of Health Interventions (ICHI) -- under development

Related Classifications

 * International Classification of Primary Care (ICPC-2)
 * International Classification of External Causes of Injury (ICECI)
 * Anatomical Therapeutic Chemical Classification System (ATC/DDD)
 * Technical aids for persons with disabilities: Classification and terminology (ISO9999)

Derived Classifications

 * International Classification of Diseases for Oncology, 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)
 * International Classification of Functioning, Disability and Health for Children and Youth (ICF-CY)

Other

 * ICD-10 Procedure Coding System (ICD-10-PCS)
 * Diagnostic and Statistical Manual of Mental Disorders (DSM)
 * Systematized Nomenclature of Medicine (SNOMED)
 * TNM Classification of Malignant Tumours
 * Medical Dictionary for Regulatory Activities (MedDRA)
 * Medical Subject Headings (MeSH)
 * Unified Medical Language System (UMLS)
 * Mendelian Inheritance in Man (OMIM)
 * Current Procedural Terminology (CPT-4)
 * Health Care Procedure Coding System (HCPCS)
 * North American Nursing Diagnosis Association (NANDA)
 * Read Codes
 * Logical Observation Identifiers Names and Codes (LOINC)
 * TIME-ITEM for medical education
 * International Classification of Headache Disorders 2nd Edition (ICHD-II)

Library classification that have medical components

 * Dewey Decimal System and Universal Decimal Classification (section 610-620)
 * National Library of Medicine classification