Overview
athenahealth delivers its clinical and administrative data through the standard HL7 v2.x messaging format. While many integration partners use the FHIR layer that athena offers, a substantial number of legacy systems still rely on the native HL7 messages that are generated directly from the athena EHR.
These native messages follow the traditional HL7 segmentfieldcomponent hierarchy, but athena adds a few customizations to support its proprietary workflows. Understanding the structure helps developers build reliable interfaces, troubleshoot message rejections, and create accurate data mappings.
Key Segments in athena Native HL7
The most common message types you will encounter are:
- ADT^A01 / ADT^A04 Patient admission, registration, and demographic updates.
- ORU^R01 Observation results, primarily lab and imaging reports.
- SIU^S12 Scheduling information (appointments, cancellations).
- DFT^P03 Billing and claim submission data.
Typical Segment Layout
MSH|^~\&|athenahealth|ATHENA|LAB|LAB|202405291200||ADT^A01|12345|P|2.5.1EVN|A01|202405291200PID|1||123456^^^ATHENA MRN||Doe^John||19800101|M|||123 Main St^^Anytown^NY^12345||555-1234PV1|1|I|ER^^^01^01||||001^Smith^Jane|||MED|||||123456|A0|
Notice the use of the standard MSH field separators (^~\&) and the inclusion of athenaspecific identifiers (e.g., ATHENA MRN).
HL7 Data Types Used by athena
athena adheres to the HL7 v2.x data type definitions but makes occasional use of the following extended types:
| Data Type | Description | Typical Use in athena |
|---|---|---|
| ST | String (text) | Patient names, comments. |
| NM | Numeric | Quantities, ages. |
| DT | Date (YYYYMMDD) | Birth date, service date. |
| TM | Time (HHMMSS) | Visit start/end time. |
| TS | Timestamp (date+time) | Message creation time. |
| CE | Coded Element | Diagnosis codes, procedure codes. |
| EI | Entity Identifier | Internal athena IDs (e.g., appointment ID). |
| XPN | Extended Person Name | Full patient name with prefix/suffix. |
| XTN | Extended Telecommunication Number | Phone numbers, email. |
When a field is optional in the HL7 standard, athena often populates it with a placeholder (e.g., empty string) rather than omitting the field entirely. This is important when parsing messages programmatically.
Mapping HL7 to athena API Objects
Many customers prefer to move from pure HL7 ingestion to a hybrid model that also uses athenas RESTful API. Below is a quick reference that shows how common HL7 fields map to the JSON structures returned by the API.
| HL7 Segment / Field | API Endpoint | JSON Property |
|---|---|---|
| PID-3 (Patient Identifier List) | /patients/{id} | patient_id |
| PID-5 (Patient Name) | /patients/{id} | first_name / last_name |
| PID-7 (Date of Birth) | /patients/{id} | date_of_birth |
| PV1-3 (Assigned Patient Location) | /encounters/{id} | department_id |
| OBR-4 (Universal Service ID) | /labs/{id} | test_code |
| OBX-5 (Observation Value) | /labs/{id} | result.value |
| AL1-3 (Allergy Code) | /allergies/{id} | allergy_code |
Because the HL7 message may contain multiple repeating segments (e.g., multiple OBX lines for a single lab order), the mapping logic should aggregate them into an array under the appropriate JSON property.
message endpoint to retrieve the raw HL7 payload for a given encounter. This can aid debugging when the API response appears out of sync with the source message. Best Practices for Working with athena HL7
- Validate MSH fields first. Ensure the sending and receiving application IDs match the contract you have with athena. A mismatched
Sending Applicationwill cause immediate rejection. - Handle optional segments gracefully. For example, the
NK1(NextofKin) segment is often omitted for adult outpatient visits, but the message may still contain placeholder delimiters. - Use the
Message Control ID(MSH-10) as your deduplication key. Even if the same patient record is sent multiple times (e.g., after an update), the control ID will be unique for each transmission. - Pay attention to the character set. athena defaults to
ISO-8859-1. If you need Unicode, set theMSH-18field toUTF-8and confirm the partner system accepts it. - Leverage the
QBP^Q22query message. When you need historic data, athena supports QBP queries that return a batch of ADT or ORU messages based on date ranges. - Log full raw messages. Because many integration issues are caused by hidden control characters, keeping the original message (including carriage returns) is invaluable for support.
- Test in the athena Sandbox. The sandbox mirrors production segment rules but allows you to send test MRNs without affecting real patient data.
Conclusion
athenahealths native HL7 implementation follows the standard v2.x conventions while embedding a few proprietary identifiers that make integration straightforward once they are understood. By familiarizing yourself with the core segments, data types, and the mapping to athenas REST API, you can build robust interfaces that handle patient demographics, appointments, lab results, and billing information reliably.
Remember to keep your parsing logic flexible, validate critical header fields, and always test against the sandbox before moving to production. With those safeguards in place, the athena HL7 native data structure becomes a powerful, standardsbased conduit for exchanging health information.
