Tracking Global Health: is ICD-10 and its Modifications the Solution?

Kathy Giannangelo, RHIA, CCS

The International Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) is collaborative product between the World Health Organization (WHO) and 10 international centers. ICD was developed in the early 20 th century as a way to collect data on the causes of death. Today ICD-10 is used to record both mortality and morbidity data. Having an international coding system provides a way in which data can be collected, analyzed, interpreted, and compared.  

Countries around the world began implementing the ICD-10 for the coding of national mortality data in 1994. According to the WHO Web site, over 35 countries use ICD-10 for the coding of national mortality statistics.1 Some of these same countries use ICD-10 to report morbidity data.

WHO publishes four specialty-based adaptations. They include ICD for Oncology (ICD-O), Application of the ICD for Dentistry and Stomatology (ICD-DA), Psychiatry (ICD-10 Chapter V codes for Mental Disorders), and Application of the ICD to Neurology (ICD-NA). Other specialty-based non-WHO publications that have been developed are Dermatology, Pediatrics, and Rheumatology and Orthopedics.2

Since WHO holds the copyrights to ICD-10, those who would like to modify the system must request permission prior to doing so. All modifications to ICD-10 must conform to WHO conventions for the ICD. In addition, certain restrictions apply whereby WHO tries to limit the type of modification to prevent change in concept and meaning of three-digit categories and four-digit codes.

Over the last several years, a number of countries have received such authorization and created modifications to ICD-10. These include Australia (ICD-10-AM), Canada (ICD-10-CA), Thailand (ICD-10-TM), United States (ICD-10-CM), Germany (ICD-10-GM), as well as others.

During a meeting of the WHO Collaborating Centres in 2002, the need for keeping track of the modifications made by the various countries was recognized. The development of a metadatabase, being referred to as ICD-10-XM, is under the auspices of the WHO Collaborating Centres ICD-10 Electronic Tools Committee chaired by Michael Schöpen from the German Institute for Medical Documentation and Information.3 This product is expected to be available to countries that do not want to develop their own clinical modification and also to help to retain comparability among those who have.

Public Health Surveillance and Monitoring

There are a number of global health problems that are tracked nationally and internationally. For example, WHO has reporting requirements related to certain communicable diseases. To be compliant with WHO's International Health Regulations (IHR), WHO Member States must report three conditions: cholera, plague, and yellow fever.4 Relapsing fever, typhus, and smallpox originally included have been removed from the list.

In addition, in 2001 the World Health Assembly made recommendations to WHO and its Member States regarding the reporting of certain diseases to advance global health security. The vision of WHO's Department of Communicable Disease Surveillance and Response (CSR) is that "every country should be able to detect, verify rapidly, and respond appropriately to epidemic-prone and emerging disease threats when they arise to minimize their impact on the health and economy of the world's population." The following diseases are covered by CSR.5

  • Anthrax
  • Avian influenza
  • Crimean-Congo hemorrhagic fever (CCHF)
  • Dengue/dengue hemorrhagic fever
  • Ebola hemorrhagic fever
  • Hepatitis
  • Influenza
  • Lassa fever
  • Meningococcal disease
  • Plague
  • Rift Valley fever
  • Severe Acute Respiratory Syndrome (SARS)
  • Smallpox
  • Tularaemia
  • Yellow fever

Finally, while the global health agenda is still focused primarily on communicable diseases, the 2003 World Health Report made note of other global epidemics in need of attention. These include cardiovascular disease, tobacco consumption, and road traffic casualties and traffic-related environmental hazards.6 And, in the 2004 report "Changing History," the spotlight is on HIV/AIDS as the world's most urgent public health challenge.7

ICD-10 Codes for Public Health Surveillance and Monitoring

Conditions classified within ICD-10 are grouped in a way that is most appropriate for general epidemiological purposes and the evaluation of healthcare. According to Merriam-Webster's online dictionary, epidemiology is a branch of medical science that deals with the incidence, distribution, and control of disease in a population.8 Therefore, one would expect ICD-10 to contain the codes necessary for use in public health surveillance and monitoring.

Taking examples of conditions relevant to global health from each of the WHO initiatives described previously, the following table compares the codes in ICD-10 and three of its modifications.

Table 1. Comparison of Codes in ICD-10 and Three of Its Modifications

Disease ICD-109 ICD-10-CM10 ICD-10-AM11 ICD-10-CA12

Cholera

A00.0-A00.9

A00.0-A00.9

A00.0-A00.9

A00.0-A00.9

Anthrax

A22.0-A22.9

A22.0-A22.9

A22.0-A22.9

A22.0-A22.9

Severe Acute Respiratory Syndrome (SARS)

U04
U04.9

None presently listed

U04
U04.9
U04
U04.9
U04.90
U04.91

Cardiovascular disease (limited to atherosclerotic cardiovascular heart disease)

I25
I25.0
I25.1

I25

I25.1

I25.10
I25.11
I25.110
I25.111
I25.118
I25.119
I25
I25.0
I25.1
I25.10
I25.11
I25.12
I25.13
I25
I25.0
I25.1
I25.10
I25.11
I25.12
I25.13
I25.14
I25.19

HIV/AIDS

B20.0-B20.9
B21.0-B21.3, B21.7-B21.9
B22.0-B22.2, B22.9
B23.0-B23.2, B23.9
B24

B20

B20
B21

B22

B23.0, B23.8

B24

 

 

 


B24

As the above table shows, the codes for cholera and anthrax are the same in ICD-10 as they are in the three modifications. However, this is not true for the other diseases. Each will be analyzed to determine the similarities and differences between the four coding systems and how they identify conditions relevant to global health.

Severe Acute Respiratory Syndrome (SARS)

According to the 2003 World Health Report "Shaping the Future," new diseases have been emerging at the rate of one per year for the last 20 years or more.13 Last year, severe acute respiratory syndrome (SARS) surfaced and caused major concerns around the world.

At the International Conference for the Tenth Revision of the International Classification of Diseases, an updating process between revisions was put in place to better address the emergence of new diseases. WHO established an Update Reference Committee (URC) for ICD-10. The URC considers proposals and submits recommendations on proposed ICD updates for mortality and morbidity to the Heads of Collaborating Centres each year. In addition, WHO set the letter "U" aside for the provisional assignment of new diseases of uncertain etiology (U00-U49) or special research (U50-U99).

During the Heads of Collaborating Centres meeting in October 2003, chapter XXII Codes for Special Purposes (U00-U99) was approved along with explanatory text, code range U00-U49, category U04 (Severe acute respiratory syndrome [SARS]), and code U04.9 (Severe acute respiratory syndrome [SARS], unspecified).14

The following table compares the codes among the three of the four coding systems. The current draft version of ICD-10-CM does not contain any codes for SARS. As one can see while slightly different, all of the codes represent conditions relevant to global health.

Table 2. Comparison of Codes for Three Systems

 

ICD-1015

-AM16

-CA17

U04 Severe acute respiratory syndrome (SARS)

X

X

X

U04.9   Severe acute respiratory syndrome (SARS)

X
unspecified

X
unspecified

X

U04.90   Suspected severe acute respiratory syndrome (SARS)

   

X

U04.91 Probable severe acute respiratory syndrome (SARS)

   

X

Atherosclerotic Cardiovascular Heart Disease

The 2003 World Health Report "Shaping the Future" identified cardiovascular diseases (CVD) as a growing problem in both industrialized as well as developing countries. This report indicates that today most deaths are due to noncommunicable diseases and just over half of these are the result of CVD.18

The following table compares the codes among the four coding systems. It demonstrates while all of the codes represent conditions relevant to global health, some of the expansion codes have different descriptors and therefore different meanings.

Table 3. CVD: Comparison of Codes

 

ICD-1019

-CM20

-AM21

-CA22

I25 Chronic ischaemic heart disease

X

X

X

X

I25.0 Atherosclerotic cardiovascular disease, so described

X

 

X

X

I25.1 Atherosclerotic heart disease

X

X
of native coronary artery

X

X

I25.10 Atherosclerotic heart disease

 

X
of native coronary artery without angina pectoris

X
of unspecified vessel

X
of native coronary artery

I25.11 Atherosclerotic heart disease

 

X
of native coronary artery with angina pectoris

X
of native coronary artery

X
of autologous vein bypass graft

I25.110 Atherosclerotic heart disease of native coronary artery with unstable angina pectoris

 

X

   

I25.111 Atherosclerotic heart disease of native coronary artery with angina pectoris with documented spasm

 

X

   

I25.118 Atherosclerotic heart disease of native coronary artery with other forms of angina pectoris

 

X

   

I25.119 Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris

 

X

   

I25.12 Atherosclerotic heart disease

   

X
of autologous bypass graft

X
of nonautologous bypass graft

I25.13

   

X
of nonautologous bypass graft

X
of artery bypass graft

I25.14

     

X
of unspecified type of bypass graft

I25.19

     

X
of unspecified type of vessel, native or graft

HIV/AIDS

As stated previously the 2004 World Health Report "Changing History" identified HIV/AIDS as the world's most urgent public health challenge. In this report, the following disturbing statistics are reported:23

  • The disease has killed more than 20 million people.
  • An estimated 34-46 million others are living with HIV/AIDS.
  • In 2003, 3 million people died and 5 million others became infected.
  • Unknown a quarter of a century ago, HIV/AIDS is now the leading cause of death and lost years of productive life for adults aged 15-59 years worldwide.

Recognizing HIV/AIDS as a global health problem, the following table compares the codes among the four coding systems. It reveals differences in the way countries have decided how to report HIV/AIDS.

Table 4. HIV/AIDS: Comparison of Codes

 

ICD-1024

-CM25

-AM26

-CA27

B20 Human immunodeficiency virus (HIV) disease resulting in infectious and parasitic diseases

X
Fourth characters 0-9

X
Human immunodeficiency virus [HIV] disease
Additional code(s) are used to ID all manifestations

X
No fourth characters
Additional
code(s) are used to ID all manifestations

 

B21 Human immuno-deficiency virus (HIV) disease resulting in malignant neoplasms

X
Fourth characters 0-3, 7-9

 

X
No fourth characters
Additional
code(s) are used to ID all manifestations

 

B22 Human immuno-deficiency virus (HIV) disease resulting in other specified diseases

X
Fourth characters 0-2, 7

 

X
No fourth characters

 

B23 Human immunodeficiency virus (HIV) disease resulting in other conditions

X
Fourth characters 0-3, 8

 

X
Fourth characters 0, 8

 

B24 Unspecified human immunodeficiency virus (HIV) disease

X

 

X

X
Human immunodeficiency virus [HIV] disease
Additional code(s) are used to ID all manifestations

Conclusion

During a keynote address at a HL7 Meeting, Dr. Ustun from WHO stated that 150 years of international collaboration and 10 revisions have yielded a common standard to classify diseases, ICD-10.28 Dr. Ustun also declared the information gathered through the use of the classifications might be useful in a meta-synthesis on the global health information:

  • To produce summary measures of population health such as health adjusted life expectancy and monitor trends
  • To study cost-effectiveness of health interventions
  • To study risks to health and comparative assessment of risk factors

There is no question that there is a need for worldwide comparability of healthcare data to provide information for improving the effectiveness of global public health policies and programs. As one can see from the data presented here, the universal use of ICD-10 and its modifications provides information for tracking global health problems. This is accomplished by the following:

  • Codes selected. The collection of essential information for effective public health policies and programs begins at the country level and is dependent upon the mandated coding system.
  • Codes reported. The reporting of ICD codes necessary for improving public health surveillance and monitoring also starts at the country level.
  • Codes exchanged. A collaborative of international, country, and local public health agencies, providers, and others focused on reporting public health information results in the exchange of information for enhancing health policy decision making and medical research.

Having an international classification, such as ICD-10, to report conditions relevant to global health supports the capacity to detect, investigate, and monitor disease, as well as their causes, and to respond appropriately to problems when identified. However, while WHO has certain restrictions to limit the type of modification to ICD-10 to prevent change in concept and meaning, caution should be exercised when codes from ICD-10 modifications are used to compare healthcare data worldwide.

Endnotes

  1. "Implementation of ICD-10 by WHO Member States." World Health Organization home page. Available at www.who.int/whosis/icd10/implemen.htm .
  2. "Implementation of ICD-10 by WHO Member States."
  3. "WHO Collaborating Centres Meeting." Coding Matters 9, no. 3 (2002): 1-3.
  4. WHO's International Health Regulations. Available at http://www.who.int/csr/ihr/en/
  5. Department of Communicable Disease Surveillance and Response (CSR). Available at http://www.who.int/csr/about/en/
  6. The World Health Report 2003. Available at http://www.who.int/whr/2003/en/
  7. The World Health Report 2004. Available at http://www.who.int/whr/2004/en/
  8. Merriam-Webster's OnLine Dictionary. Available at http://www.m-w.com/
  9. ICD-10, World Health Organization, 1992.
  10. ICD-10-CM, Pre-release draft, June 2003. Available at http://www.cdc.gov/nchs/about/otheract/icd9/icd10cm.htm
  11. ICD-10-AM, Third Edition, National Centre for Classification in Health.
  12. ICD-10-CA, Version 2003 and Errata and Addenda #1, Canadian Institute for Health Information. Available at http://secure.cihi.ca/cihiweb/en/downloads/bl_class_22aug2003_Errata1folio_e.pdf
  13. The World Health Report 2003. Available at http://www.who.int/whr/2003/en/
  14. Ratified by WHO-FIC Network at the annual meeting in Cologne, October 2003.
  15. ICD-10, World Health Organization, 1992.
  16. ICD-10-AM, Third Edition, National Centre for Classification in Health.
  17. ICD-10-CA, Version 2003, Errata and Addenda #1, Canadian Institute for Health Information. Available at http://secure.cihi.ca/cihiweb/en/downloads/bl_class_22aug2003_Errata1folio_e.pdf
  18. The World Health Report 2003. Available at http://www.who.int/whr/2003/en/
  19. ICD-10, World Health Organization, 1992.
  20. ICD-10-CM, Pre-release draft, June 2003. Available at http://www.cdc.gov/nchs/about/otheract/icd9/icd10cm.htm
  21. ICD-10-AM, Third Edition, National Centre for Classification in Health.
  22. ICD-10-CA, Version 2003, Canadian Institute for Health Information.
  23. The World Health Report 2004. Available at http://www.who.int/whr/2004/en/
  24. ICD-10, World Health Organization, 1992.
  25. ICD-10-CM, Pre-release draft, June 2003. Available at http://www.cdc.gov/nchs/about/otheract/icd9/icd10cm.htm
  26. ICD-10-AM, Third Edition, National Centre for Classification in Health.
  27. ICD-10-CA, Version 2003, Canadian Institute for Health Information.
  28. Ustun, Bedirhan. HL7 17 th Annual Plenary and Working Group Meeting, 2003.

Source: 2004 IFHRO Congress & AHIMA Convention Proceedings, October 2004