Relationship of Terminologies and Classifications
Classifications and terminologies are designed for distinctly different purposes and to satisfy diverse user data requirements. Consider them complementary, as neither a clinical terminology nor a classification can, by itself, serve all the purposes for which health information is currently used, or will be used in the future.
Classification systems such as ICD-9-CM, ICD-10-CM, and ICD-10-PCS are considered “output” systems and are not intended or designed for the primary documentation of clinical care. They are typically used for external reporting requirements or other uses where grouping data is advantageous. A classification system arranges or organizes similar or related entities for easy retrieval, and aggregates granular clinical concepts into manageable categories for secondary data purposes. The current use of data derived from classification systems goes beyond the purposes for which such data were used in the 1970s, when ICD-9-CM was first designed and implemented.
How data is used today:
- Measuring the quality, safety (or medical errors), and efficacy of care
- Making clinical decisions based on output from multiple systems
- Enabling the connectivity of information systems for continuity of care
- Designing payment systems and processing claims for reimbursement
- Conducting research, epidemiological studies, and clinical trials
- Setting health policy
- Designing healthcare delivery systems
- Monitoring resource utilization
- Improving clinical, financial, and administrative performance
- Identifying fraudulent or abusive practices
- Managing care and disease processes
- Tracking public health and risks
- Providing data to consumers regarding costs and outcomes of treatment options
In contrast, clinical terminologies such as SNOMED-CT® are “input” systems designed for the primary documentation of clinical care. Since they codify the clinical information captured during the course of patient care, terminologies can only be used in electronic health record (EHR) systems.
Together, standard clinical terminologies and classifications represent a common medical language that allows data to be shared. Therefore, standard, modern clinical terminologies and classifications must be incorporated into EHR systems in order to achieve system interoperability and to realize the benefits of a national health information infrastructure.
The expanded availability of SNOMED-CT®, made possible by the federal government licensing agreement, increases the urgency of replacing ICD-9-CM with ICD-10-CM/PCS, so the development of mapping tools to the ICD-10-CM and ICD-10-PCS can be initiated. For information on mapping, explore the data mapping resources pages.
Resources for more information: