ICD-11: Learning from the past and embracing the future

Health information management (HIM) professionals, it’s time to turn your attention to ICD-11. The World Health Assembly adopted this updated coding system in 2019, and it became effective on Jan. 1, 2022. The new system enhances the recording, analysis, interpretation and comparison of morbidity and mortality data, ensuring more effective interoperability and data analysis. While there is no specific U.S. implementation date for the latest ICD version, it’s never too early for education.
 

A brief history of ICD

The International Classification of Diseases (ICD) has a rich history dating back to 1532 when John Graunt created the London Bills of Mortality, a statistical system for reporting burials in London parishes caused by an outbreak of the plague. Over the next 300 years his work was expanded upon by other great statisticians, leading to the development of a world-renowned, international classification of death (mortality) and disease (morbidity), known as the Bertillon Classification of Causes of Death.

Today, 35 countries are actively using ICD-11, with 64 countries in various states of implementation. More seasoned coders remember the transition from ICD-9 to ICD-10, while newer coders have more experience with ICD-10. However, future coders will become adept at using ICD-11, which has a newly developed foundation that can be expanded upon without a need for significant revisions moving forward.
 

Key features of ICD-11

ICD-11 is designed for a variety of uses, all of which are crucial for an organization’s bottom line and quality patient care, including:

• patient record data mining
• functional assessment and decision support
• disease prevention and research
• patient, drug and device safety
• diagnosis related group (DRG) resources
• public health death data

One highlight of the updated system is improved identification and classification of patient safety events. This is achieved by tracking the cause and injury from documented patient events. Historically, care providers and hospitals in the U.S. have struggled to consistently identify adverse patient events, and this change should be an improvement.

Two unique features of ICD-11 are linearizations and post-coordination rules. Linearizations are subsets in ICD-11 used for specific purposes, such as international mortality and morbidity reporting. The World Health Organization’s (WHO) version of the ICD-10 classification contains 14,000 codes and is used worldwide in healthcare for reporting morbidity and mortality statistics, reimbursement systems and automated medical decision support. While it meets the needs of some countries, others made clinical modifications to meet specific reporting needs, resulting in multiple varying classifications that could not be used to compare data globally. 

Some of these clinically modified classifications include: Canada’s ICD-10-CA, which is available in both English and French, Australia’s ICD-10-AM, which is used by New Zealand, Ireland, Saudi Arabia and several other countries, and the U.S. ICD-10-CM, which contains more than 70,000 codes and is used by India, the Philippines, UAE and several others. 

The WHO’s goal to compare data globally required the creation of a Foundation of entities, which is a broad collection of more than 80,000 diseases, conditions, injuries, etc., from which each country can create a customized linearization (tabular list) specific to their needs. By having all nations derive a tabular list (linearization) from the same Foundation, data can then be compared on a global scale. Of course, prior to implementing ICD-11 in the U.S., additional research will be needed to ensure the Foundation entities meet the U.S.-specific data needs.

Post-coordination is a system that allows more detail to be added to an entity within a linearization, providing flexibility for new codes without determining each combination needed. Post-coordination details include information like the specific anatomic site affected, laterality, manifestation, histopathology and underlying cause. 
 

Coding in ICD-11

ICD-11 contains many of the same disease categories (referred to as entities in the ICD-11 Foundation) included in ICD-10-CM, such as neoplasms, diseases of the circulatory system, pregnancy, and signs and symptoms. It also includes additional core chapters on diseases of the immune system, sleep-wake disorders and conditions related to sexual health. 

For example, “acute sinusitis” can be coded from the ICD-10 or ICD-11 index using the term “sinusitis” and further narrowing the term to “acute.” While ethmoid sinusitis is reported with one code in ICD-10, in ICD-11 it requires three codes to fully describe the condition. It is important for physicians to be specific with anatomic locations and laterality so coders can select the appropriate post-coordination codes.  

Example:

Managing transition and implementation

While the U.S. has not yet adopted ICD-11, organizations should start internal discussions about what is needed for implementation. Being proactive does not require an enormous time or financial commitment, and healthcare organizations should not wait to get their feet wet.

The American Hospital Association (AHA) recently submitted correspondence to the Center for Disease Control and Prevention (CDC) for additional information on ICD-11. The AHA supports the efforts to transition to ICD-11 and the possibility of offering enhanced reportable data and consistency.

One element not yet considered in the transition is the impact of artificial intelligence (AI). In November 2023, the American Health Information Management Association (AHIMA) published survey results on workforce shortages and the use of AI, which revealed that 45 percent of respondents reported the adoption of AI in their electronic health records (EHR) and coding systems.

While it may appear that the transition to ICD-11 is years away, there is no time like the present to start internal discussions and initial education on the new classification. Early preparation could mean the difference between a smooth transition and one that is fraught with chaos and challenges. To begin learning now, explore these free resources: 

• The WHO’s ICD-11 Training Package 
• The WHO’s ICD-11 Implementation or Transition Guide
• ICD-11 fact sheet
   

Karla VonEschen, MS, CCDS-O, CPC, CPMA, is a clinical analyst at Solventum. 

Aimee L. Wilcox, CPMA, CCS-P, CST, MA, MT, is a coding analyst at Solventum.