The National Transition from ICD-9 to ICD-10

The World Health Organization’s (WHO) International Classification of Diseases and Related Health Problems, 10^th Revision (ICD-10) is the most recent version available for the medical coding of health diagnoses and procedures. Since 1994, more than 153 countries have used ICD-10. However, the United States is the only industrialized nation to continue using the older version ICD-9 because ICD-9 is deeply imbedded in the electronic systems and processes used for U.S. health care delivery, financing, and reporting.¹

On January 16, 2009, the U.S. Department of Health and Human Services (HHS) published a final rule for implementing ICD-10. This HHS final rule concurrently adopts ICD-10, Clinical Modification (ICD-10-CM) for diagnosis coding and ICD-10, Procedure Coding System (ICD-10-PCS) for inpatient hospital procedure coding.² Thus, on October 1, 2013, ICD-10 will replace ICD-9 in the United States.

In the United States, ICD-9 is used to monitor quality; however, this was not its original purpose. ICD-9 does not allow for the advances in medical technology and procedures that have occurred in the past 30 years. Often, these new procedures are identified by a single code that was developed for older procedures that are no longer commonplace, or the new procedures are coded into a category for other. ICD-9 limits the ability to code innovative procedures uniquely. For example, inaccurate or insufficient data and details can limit the knowledge of diagnoses, procedures, severity, quality, and technology. Emerging health care practices, which rely on aggregating and analyzing clinical data and comparing it with international data, are limited because they cannot be automated by using ICD-9.¹

ICD-9 uses approximately 17,000 codes, whereas ICD-10 has more than 155,000 codes that can accommodate many new diagnoses and procedures. The expanded codes in ICD-10 will help the United States implement electronic health records. These additional codes will provide much more detail, which can be automated for electronic transactions. In addition, a deeper level of analysis will help to improve efficiency by identifying specific health conditions.² Upgrading to ICD-10 is a necessary step to improving the information technology of medical data and records. ICD-10 data are more easily retrieved in electronic format than ICD-9-CM data.³

In addition, HHS released a separate final rule to adopt the updated Health Insurance Portability and Accountability Act (HIPAA) X12 standard, Version 5010 transactions sets.⁴ For electronic claims, Version 5010 will replace the current version (4010/4010A) and accommodate the ICD-10 code structure. This final rule calls for Version 5010 compliance by January 1, 2012, for electronic health care claims. Any electronic claims that do not use Version 5010 standards after that date cannot be paid. ICD-10 diagnosis and procedure codes must be used for all health care services provided in the United States on or after October 1, 2013. Claims with ICD-9 codes for services provided on or after October 1, 2013, will not be paid.⁵ Former HHS Secretary Mike Leavitt said, “We are taking a giant step forward developing a health care system that focuses on quality and affordability through implementation of health information technology.”² Leavitt also said, “Conversion to ICD-10 is essential to the development of a nationwide electronic health information environment, and the updated X12 transaction standards are a critical step in the implementation of the new codes.”²

The switch to ICD-10 codes should be beneficial to cancer registries. ICD-10 codes will not look very different to cancer registries because the International Classification of Diseases for Oncology (ICD-O, second and third editions) topography codes are based upon the malignant neoplasm section of ICD-10. ICD-O has been in use for U.S. cancer surveillance since 1992 (second edition) and 2001 (third edition).⁶

Code analysis is an essential component of research because there is no direct access to the patient records. A primary difference between ICD-9 and ICD-10 codes is that ICD-10 uses alphanumeric codes that have more data fields than ICD-9 codes. ICD-10 reflects advances in clinical knowledge and medical practice by reclassifying diseases. Thus, ICD-10 codes will be much more specific than ICD-9 codes and will require precise clinical documentation to assign the proper code.³

ICD-10-CM codes will enhance cancer registry data. For instance, behavioral risks, such as smoking history, lack of exercise, or poor dietary habits, are more specifically defined in ICD-10.³ This information is valuable to tracking public health risks for cancer. Other new ICD-10 features include the ability to include laterality and gender within the code, such as C50.511 (malignant neoplasm of lower-outer quadrant of right female breast).

The ICD-9-CM “V” codes, or Factors Influencing Health Status and Contact with Health Services codes, are incorporated into the main classification. For instance, ICD-10-CM code C91.41 (hairy cell leukemia, in remission) can be used rather than a V10 code for history of leukemia. Some of the ICD-10-CM diagnosis codes will differ from the ICD-O-3 primary site codes. For example, ICD-10-CM codes in the C43 range denote melanoma of the skin, whereas ICD-O-3 codes skin to C44 with a histology code. ICD-10-CM will require new training materials for registries, especially for case finding and matching with vital statistics for death clearance activities.

ICD-10 will expand considerably our knowledge about the health of the population and the care they receive. Benefits will come from a more meaningful specificity of the codes, which permits more patient information to be recorded and transferred.⁷ Referring to the final rules for ICD-10 and X12 Version 5050 for transactions, Leavitt again said, “These regulations will move the nation toward a more efficient, quality-focused health care system by helping to accelerate the widespread adoption of health information technology.”⁸

A complete, up-to-date classification system is necessary to create electronic health records with the interoperability needed for data sharing in a nationwide health information network. Once registries are beyond the learning curve, links can be optimized through more specific codes for both collecting and greatly enhancing registry data. The detailed ICD-10 will provide a more robust data set for evaluating public health.