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Terminologies and Coded Values

FHIR® resources extensively utilize coded values to effectively represent various healthcare concepts. These values adhere to FHIR®'s standardized data format, allowing for consistent and interoperable healthcare data representation. A code system is a structured collection of codes relevant to a particular domain, each associated with a specific meaning.

What Are Coded Values?​

Coded values are standardized representations of healthcare data concepts. They enable consistent interpretation and facilitate efficient data exchange across systems. For instance:

  • A lab test could be represented with a specific LOINC code.
  • Medical diagnoses might be encoded using ICD (International Classification of Diseases) standards.

By adhering to standard coding systems, healthcare data becomes more interoperable and machine-readable.

Understanding Code Systems​

A code system is a collection of codes used to represent data within a domain, along with definitions for each code. These systems standardize how information is conveyed, enabling smoother data exchange and analysis.

Examples of Code Systems:​

  1. LOINC (Logical Observation Identifiers Names and Codes)

    • Used for lab tests, measurements, survey answers, and other observable data.
    • Ensures uniform representation of clinical observations across systems.

  2. ICD (International Classification of Diseases)

    • Encodes medical conditions and diagnoses.
    • Widely used for epidemiology, health management, and billing.

  3. SNOMED CT (Systematized Nomenclature of Medicine—Clinical Terms)

    • Provides comprehensive coverage of clinical terms.
    • Supports detailed and precise representation of healthcare data.

  4. RxNorm

    • Represents drugs and clinical drug delivery systems.
    • Facilitates communication between pharmacy systems and healthcare providers.

Locally-Defined Code Systems:​

While many code systems are created by international organizations, FHIR® also allows for the use of locally-defined systems. These systems can address unique requirements or scenarios within specific organizations or regions.

Operations with Coded Values​

FHIR® supports a range of operations to handle coded values effectively:

  • Code Validation: Ensures codes used in data are valid according to their respective code systems.
  • Mapping: Maps codes between different code systems to support data exchange.
  • Expansion: Expands a ValueSet, returning all codes within a specific set of data.
  • Translation: Translates codes from one terminology system to another, enabling interoperability.

Benefits of Using Coded Values in FHIR®​

  1. Interoperability:

    • Standardized codes facilitate seamless data exchange between disparate systems.

  2. Consistency:

    • Eliminates ambiguity in how healthcare data is represented and interpreted.

  3. Scalability:

    • Supports the integration of additional systems and data sources over time.

  4. Efficiency:

    • Simplifies data analysis and processing through structured representation.

For more information on how FHIR® supports terminologies and coded values, feel free to contact us.