The history of the International Classification of Diseases and its evolution over time
The International Classification of Diseases (ICD) is one of the most significant tools used in healthcare today, providing a standardized language for documenting diseases, injuries, symptoms, and causes of death. Developed by the World Health Organization (WHO), ICD has evolved significantly over time to reflect advances in medical science and changes in societal needs.
The first iteration of ICD was created in 1893 by Dr. Jacob Biggs Morison at a time when different countries were using their own disease classifications that lacked standardization. The initial purpose of this classification system was to facilitate the exchange of health information between countries, which had become increasingly important due to advances in transportation and migration.
The first version of ICD, known as ICD-1, consisted of 50 categories including accidents, infectious diseases, neoplasms (tumors), and mental disorders.
It was not without its limitations, however, as it failed to recognize certain conditions such as diabetes mellitus or heart disease.
Nevertheless, ICD-1 served as a basis for subsequent revisions that would address these shortcomings while expanding the scope of the classification system.
ICD-2 was published in 1905 and introduced several new categories including diseases of the nervous system and certain genetic disorders.
It also included codes for external causes of morbidity such as injuries, poisonings, and other adverse environmental factors.
This version saw increased adoption by countries around the world, particularly in Europe and North America.
ICD-3 was published in 1928 during a time when medical knowledge was rapidly expanding due to advances in microbiology and immunology.
It included codes for diseases of the blood and blood-forming organs as well as congenital malformations and deformities.
This version also introduced diagnostic criteria, which defined specific symptoms or laboratory findings associated with each disease entity.
ICD-4 was published in 1938 and marked a significant departure from previous versions by incorporating both clinical and pathological data into the classification system.
It included codes for diseases of the respiratory, digestive, musculoskeletal, and other organ systems. This version also introduced diagnostic criteria that were more specific and detailed than those in ICD-3.
ICD-5 was published in 1948 and reflected postwar advances in medicine including the discovery of antibiotics and vaccines. It included codes for new diseases such as poliomyelitis, tuberculosis, and other infectious diseases that were becoming more prevalent at the time.
ICD-6 was published in 1957 and introduced significant changes to the classification system including a move away from purely descriptive diagnoses towards more specific diagnostic criteria. It also included codes for new conditions such as birth defects, mental retardation, and genetic disorders. This version saw widespread adoption by countries around the world and became the de facto standard for disease classification in healthcare settings.
ICD-7 was published in 1965 and included codes for new conditions such as heart failure, stroke, and other cardiovascular diseases that were becoming increasingly prevalent due to changes in lifestyle factors such as diet and physical activity. It also introduced codes for environmental health hazards including air pollution and radiation exposure.
ICD-8 was published in 1975 and included codes for new conditions such as AIDS, which had emerged as a global health crisis during the decade prior. It also incorporated diagnostic criteria from ICD-6 into its structure to provide more specific diagnoses. This version saw widespread adoption by countries around the world and became the standard for disease classification in many healthcare settings.
ICD-9 was published in 1978 and included codes for new conditions such as cerebral palsy, autism spectrum disorder, and other developmental disabilities that were becoming more recognized at the time. It also introduced more specific diagnostic criteria to improve accuracy and consistency of diagnoses across different healthcare settings.
ICD-10 was published in 1993 and represented a significant departure from previous versions due to its increased focus on clinical relevance and the inclusion of procedures, medical devices, and other non-disease related categories. It included codes for new conditions such as Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative disorders that were becoming more prevalent in aging populations.
ICD-11 was published in 2018 and represents the most recent iteration of ICD. It includes codes for new conditions such as e-cigarette or vaping product use-associated lung injury (EVALI), COVID-19, and other emerging diseases that have gained prominence during the past decade. The latest version also incorporates advances in genomic medicine including codes for pharmacogenetic testing and personalized healthcare services.
In conclusion, ICD has evolved significantly over time to reflect advances in medical science and changes in societal needs. From its humble beginnings as a tool for facilitating the exchange of health information between countries, it has grown into one of the most important diagnostic tools used in modern healthcare settings around the world. With each new iteration, ICD becomes more comprehensive and accurate, helping healthcare providers deliver better care to patients while also supporting public health initiatives at a global level.
The ICD serves various purposes, such as:
Standardization of diagnosis and treatment: The ICD helps to standardize the clinical documentation and coding of diseases, injuries, and related conditions. This ensures that patients receive appropriate care based on their diagnoses and improves communication between healthcare providers.
Epidemiological research: The ICD is widely used in epidemiological studies to monitor trends and patterns of disease occurrence and control measures’ effectiveness.
Resource allocation: Governments, insurance companies, and other organizations use the ICD to allocate resources for healthcare services based on the prevalence and burden of different diseases.
International comparison: The ICD facilitates international comparisons in disease incidence, mortality, and morbidity rates across countries and regions. This helps identify areas that need improved public health interventions and resource allocation.
Data sharing: The ICD promotes data sharing between countries, enabling the exchange of information on various aspects of public health.
Global health priorities: The ICD informs global health priorities by providing a framework for identifying emerging diseases, epidemics, and pandemics.
Quality improvement: The ICD supports quality improvement initiatives in healthcare by providing a standardized language for recording clinical data and monitoring outcomes.
Legal and regulatory purposes: The ICD is used for legal and regulatory purposes, such as medical malpractice litigation or the approval of pharmaceutical products.
Health policy development: The ICD supports evidence-based health policymaking by providing a comprehensive database on diseases, injuries, and related conditions that affect populations globally.
Public awareness and education: The ICD contributes to public awareness and education about various health issues by facilitating the dissemination of information and data to the general population.
The eleventh edition of the ICD (ICD-11)
Expanded coverage: The ICD-11 provides more comprehensive coverage of mental and behavioral disorders, including new categories for gaming disorder, disruptive mood dysregulation disorder in children, and other neurodevelopmental disorders.
Revised structure: The ICD-11 introduces a revised chapter structure that better reflects current medical knowledge and enhances its usability by healthcare professionals.
Improved precision: The ICD-11 includes more precise diagnostic criteria for various conditions, leading to improved accuracy in diagnosis and treatment planning.
Integration of new technologies: The ICD-11 integrates emerging technologies such as artificial intelligence (AI) and machine learning into its development process, ensuring that the classification system stays up-to-date with advances in healthcare.
Inclusion of environmental factors: The ICD-11 acknowledges the role of environmental factors in disease causation by including new codes for exposure to non-ionizing radiation and other environmental hazards.
Enhanced cultural sensitivity: The ICD-11 takes into account cultural and social diversity by providing more extensive descriptions of various conditions that may manifest differently across different cultures.
Challenges and Future Developments:
While the ICD has proven to be an invaluable asset in healthcare, it is not without challenges. Keeping the classification system updated with rapidly evolving medical knowledge and emerging diseases remains a continuous task. Additionally, the implementation of the ICD in different healthcare systems worldwide can be complex, requiring ongoing efforts to ensure uniformity and accuracy.
Looking ahead, advancements in technology, such as artificial intelligence and machine learning, may play a role in enhancing the efficiency of coding and classification processes.
American Academy of Professional Coders (AAPC)
AAPC is the world’s largest training and credentialing organization for the business of healthcare, with members worldwide working in medical coding, billing, auditing, compliance, clinical documentation improvement, revenue cycle management, and practice management.
https://www.aapc.com
AAPC’s Official CPC® Certification Study Guide
International Classification of Diseases certification examples
AHIMA (American Health Information Management Association):
Certified Coding Specialist (CCS)
Certified Coding Specialist – Physician-based (CCS-P)
AAPC (American Academy of Professional Coders):
Certified Professional Coder (CPC)
CCA (AHIMA’s Certified Coding Associate):
Certified Coding Associate
HCS-D (Home Care Coding Specialist – Diagnosis):
Offered by the Board of Medical Specialty Coding & Compliance (BMSCC)
CCA-P (AHIMA’s Certified Coding Associate – Physician-based):
Certified Coding Associate – Physician-based
International Classification of Diseases certification examples
Before pursuing any certification, it’s essential to check with the respective certification body for the most up-to-date information on their certification programs.
Additionally, healthcare coding and billing practices may evolve, so staying informed about industry changes is crucial.
CD-10-CM Overview
ICD-10-CM is the International Classification of Diseases, Tenth Revision, Clinical Modification. It’s a medical classification system that’s used to code and classify diseases, injuries, and other health conditions.
The ICD-10-CM system is used in the United States by healthcare providers, researchers, and other healthcare professionals to accurately document and report diagnoses and medical conditions. It replaced the previous ICD-9-CM coding system in October 2015.
The ICD-10-CM coding system is made up of alphanumeric codes that represent specific diseases, conditions, and injuries. These codes are used to classify and track medical data for statistical purposes, as well as for reimbursement and billing purposes.
ICD-10-CM codes consist of three to seven characters. The first three characters represent the category of the disease or condition, while the fourth through seventh characters provide additional detail about the diagnosis.
For example, the ICD-10-CM code for diabetes mellitus type 2 is E11.9.
The “E” stands for “endocrine, nutritional, and metabolic diseases,” the “11” represents the category for diabetes mellitus, and the “.9” indicates that the specific type of diabetes mellitus is unspecified.
The ICD-10-CM system is updated annually by the Centers for Medicare and Medicaid Services (CMS) and the National Center for Health Statistics (NCHS). These updates include new codes for emerging diseases and conditions, as well as revisions to existing codes based on new medical research and clinical practices.
ICD-10-CM coding is important for healthcare providers because it ensures that medical information is accurately documented and reported, which helps to improve patient care and outcomes. It also helps to ensure that healthcare providers are reimbursed appropriately for the care they provide.
In addition to healthcare providers, ICD-10-CM coding is also used by researchers, public health officials, and policymakers to track and analyze trends in disease prevalence, healthcare utilization, and healthcare costs.
The ICD-10-CM coding guidelines are a set of rules and instructions for coding and reporting diagnoses using the ICD-10-CM coding system.
These guidelines are developed by the Centers for Medicare and Medicaid Services (CMS) and the National Center for Health Statistics (NCHS), and they are updated annually.
The purpose of the ICD-10-CM coding guidelines is to provide uniformity and consistency in the coding and reporting of medical data. They are intended to ensure that healthcare providers and coders are using the correct codes, sequencing codes in the correct order, and documenting the necessary details to support the code assignment. Some of the key ICD-10-CM coding guidelines include:
Code to the highest level of specificity: Coders should use the most specific diagnosis code available that accurately reflects the patient’s condition.
Use all available information: Coders should review all available medical documentation to accurately capture the patient’s condition, including diagnostic tests, physician notes, and other relevant information.
Sequence codes in the correct order: Coders should sequence codes in the order of the patient’s condition and any underlying causes or complications.
Use combination codes when available: Combination codes are codes that describe both the underlying condition and any associated complications or manifestations.
Coders should use combination codes when available to accurately capture the full picture of the patient’s condition.
Follow official coding conventions: Coders should follow the official coding conventions and guidelines outlined in the ICD-10-CM coding manual.
Use unspecified codes sparingly: Unspecified codes should only be used when there is no available documentation to support a more specific code.
Overuse of unspecified codes can lead to inaccurate data and reimbursement denials.
Document laterality: When coding conditions that affect paired organs or body parts, such as eyes, ears,or kidneys, coders should document the laterality, or which side is affected. This helps to ensure accurate coding and reporting.
Use external cause codes when appropriate: External cause codes are codes that describe the circumstances surrounding an injury, such as the cause, intent, place of occurrence, and activity at the time of the injury. These codes are used to identify the cause of the injury and provide data for injury prevention efforts.
Document medical necessity: In order for a service or treatment to be reimbursed, it must be medically necessary. Coders should ensure that the medical documentation supports the medical necessity of the services provided.
Follow coding updates: The ICD-10-CM coding system is updated annually, and it’s important for healthcare providers and coders to stay up-to-date with the latest coding changes and updates. This ensures that they are using the most current and accurate codes for their patients.
Coding Conventions and Format
ICD-10-CM coding conventions refer to the rules and standards that are used to create the alphanumeric codes that represent medical diagnoses and conditions. These conventions include the use of parentheses, brackets, and other symbols to indicate certain information about the codes.
Here are some key ICD-10-CM coding conventions:
Brackets: Brackets are used to enclose synonyms, alternative wording, or explanatory phrases. For example, the code for asthma with acute exacerbation is J45.901 [45.901].
Parentheses: Parentheses are used to enclose supplementary words that may or may not be present in the medical record. For example, the code for chronic obstructive pulmonary disease is J44.9 (chronic obstructive pulmonary disease unspecified).
Colons: Colons are used to separate category codes from subcategory codes. For example, the code for atrial fibrillation is 148, while the subcategory code for chronic or persistent atrial fibrillation is 148.1.
Excludes notes: Excludes notes indicate that a code should not be used with another code, even if the patient has both conditions. For example, the code for malignant neoplasm of the breast is C50.9, while the code for benign neoplasm of the breast is D24.9. The two codes have an excludes note, indicating that they should not be used together.
Combination codes: Combination codes are codes that describe both the underlying condition and any associated complications or manifestations. For example, the code for diabetes mellitus with diabetic retinopathy is E11.36.
ICD-10-CM codes are also formatted in a specific way.
The codes are alphanumeric and consist of three to seven characters. The first character is always a letter, while the second character is always a number. The third through seventh characters can be either letters or numbers. ICD-10-CM codes are organized into categories and on the type of condition or disease.
The first three characters of the code represent the category, while the fourth through seventh characters provide additional detail about the diagnosis.
For example, the category code for neoplasms (tumors) is “C.” The fourth character of the code provides more detail about the specific type of neoplasm, such as whether it’s malignant or benign, where it’s located in the body, and other relevant details.
The ICD-10-CM also includes codes for external causes of injury and poisoning, such as falls, motor vehicle accidents, and drug overdoses. These codes describe the circumstances surrounding the injury or poisoning, such as the cause, intent, place of occurrence, and activity at the time of the event.
The ICD-10-CM also includes codes for factors that influence health status and contact with health services, such as personal history of diseases, complications of surgical and medical care, and routine health examinations.
In addition to the conventions and format of the codes, it’s important for coders to use their clinical knowledge and judgment to accurately code and report diagnoses. Coders should review all available medical documentation to ensure that they are using the most specific code available, documenting the necessary details to support the code assignment, and following the ICD-10-CM coding guidelines.
