Code Systems
Health Gorilla uses nationally recognized code systems to ensure semantic consistency, interoperability, and structured data exchange. All coded elements in FHIR® resources follow standardized vocabularies defined by HL7 and other regulatory bodies.
Supported Code Systems
| Code System | Description |
|---|---|
| LOINC® | Represents laboratory tests, vital signs, and clinical document types. |
| SNOMED CT® | Identifies conditions, procedures, allergies, and encounter reasons. |
| RxNorm | Defines medications, ingredients, and dosage forms. |
| ICD-10-CM | Used primarily for diagnosis and condition coding. May appear in Observations and Conditions. |
| CPT® / HCPCS | Represents procedures, services, and billing codes commonly used in claims and encounter documentation. |
| CVX | Codes for vaccines, used in immunization resources. |
| NDC | National Drug Codes, used in some lab orders and medication records. |
| UCUM | Unified Code for Units of Measure, used in quantitative results and observations. |
| HL7 Value Sets | Includes standardized values for administrative fields such as gender, marital status, and communication preferences. |
| Health Gorilla Custom Codes | Used for workflow routing, result tagging, and document classification. Always scoped using a custom system URI. |
Coded Field Structure
Most coded elements use a CodeableConcept that contains one or more coding objects, each with the following fields:
code: The code value from the source vocabularysystem: The URI representing the code systemdisplay: An optional human-readable description
Multiple codings may be included in a single field to support mapping across code systems. Always preserve the original code and system values to ensure accurate rendering, validation, and interoperability.
Note: Units of measure use UCUM codes in the Quantity datatype (valueQuantity.system, valueQuantity.code) instead of a CodeableConcept.
Value Sets and Constraints
Many fields are constrained by HL7-defined value sets or Health Gorilla-specific profiles. When submitting or validating FHIR resources, confirm that coded values align with the expected value set for each field. Examples include:
- Immunizations: Bound to CVX codes.
- Procedures: May require CPT or SNOMED CT codes.
- Medications: Must include RxNorm or NDC identifiers.
- Laboratory tests and results: Require LOINC codes.
- Units of measure: Must use UCUM codes.