Although there continues to be some interest in the development of an international classification of procedures to accompany ICD-10, particularly from smaller countries, WHO only recently began testing of an International Classification of Health Interventions (ICHI). ICHI contains approximately 600 codes. Review of international initiatives and literature indicates that the application of procedure classifications varies widely from country to country. The availability and rapid evolution of technology is also somewhat country specific. This factor generates a need for ongoing updating of the classification standards to ensure continued relevance and usefulness. Therefore, many countries are developing one or more procedure classifications for use in various settings. This highlights the importance of developing a new procedure classification relevant to Canadian needs and controlled by Canadians for the necessary updating to reflect medical and technologic advances. This task has been undertaken by the CIHI as part of its mandate relating to the maintenance and development of national health information standards.

Improved Scope and Content

When the CCP was originally developed, in the 1970s, it was designed primarily for use in the acute, inpatient setting. Its scope was heavily weighted toward surgical procedures. Diagnostic and therapeutic procedures, especially those done by nonphysicians, were not as well covered.

The new CCI provides for a comprehensive range of interventions. It reflects the broad spectrum of providers and the variety of its potential applications across the continuum of health care services.

The structure of the current CCP and that of the procedure section of the ICD-9-CM are relatively inflexible and prohibit comprehensive updating to accommodate new procedures and techniques. Over the past few years there has been a significant move to perform many operative procedures in a minimally invasive way, through the use of endoscopic approaches and lasers, for example. Such technologic advances mean more procedures can now be carried out as day-surgery procedures rather than as inpatient procedures, with an associated shift in resource use. The lack of space within the existing coding structure hampers the systematic capture of this detail. CCI provides for the identification of this type of information. It also includes significant enhancements and additions in the area of diagnostic and therapeutic services.

Structure and Presentation

In 1993 Statistics Canada and the Hospital Medical Records Institute (one of CIHI's founding organizations) investigated options for the best way to approach the overall coding structure of the new classification. An approach involving the use of a prefix to define broad types of procedures or interventions (e.g., diagnostic, therapeutic) was finally adopted. This prefix would become an integral part of each intervention code.

This approach has the advantage of allowing sections or modules of the classification to be developed and published independently of each other while still maintaining conformity with the overall coding structure.

Because of the additional level of detail that is provided in CCI (more than 18,000 codes, compared with 4,000 in CCP), electronic search capabilities are provided to facilitate its use. The "built-in" hierarchic structure also allow data aggregation and analysis to an extent that is not easily done with the previous classifications.

Development and Validation

Development of the draft classification, which started in early 1996, was completed at the end of 1997. Revisions to various sections were then made in response to comments received during an external review process. This review process involved various users or interested parties, including clinicians, health records personnel, governments and researchers.

As well, a national advisory group was established to provide overall guidance to the CCI project team, and a number of forums and meetings with various health care professional groups were held. These forums provided input into the development of CCI, ensuring that the classification meets the information needs of users, including utilization management, quality reviews and research.