HL7 - Health Level 7

What Is HL7?

HL7, or Health Level Seven, refers to a set of international standards for the exchange, integration, sharing, and retrieval of electronic health information. These standards are developed by Health Level Seven International, a nonprofit organization dedicated to providing a framework for healthcare systems to communicate seamlessly.

HL7 is essential in ensuring that different healthcare software systems, such as electronic health records (EHRs), lab systems, pharmacy systems, and billing platforms, can effectively communicate and share data, even if they are built by different vendors. 

What Does "Health Level Seven" Mean?

The “Seven” in Health Level Seven represents Layer 7 (the application layer) of the OSI (Open Systems Interconnection) model, a framework that defines how different computer systems communicate over a network. This layer is responsible for end-user services like email, file transfers, and in healthcare, data sharing between applications. 

Key HL7 Standards

HL7 includes multiple standards and messaging frameworks, but some of the most widely used include:

1. HL7 Version 2 (V2)

   The most widely implemented standard globally.

   Defines a messaging format that allows healthcare systems to exchange clinical and administrative data, such as patient admissions, lab results, and billing information.

   Supports real-time data exchange in hospital environments.

    

2. HL7 Version 3 (V3)

   A more structured and complex framework using XML for data exchange.

   Designed for improved interoperability and data consistency.

    

3. HL7 CDA (Clinical Document Architecture)

   Used for creating standardised electronic documents such as discharge summaries, progress notes, and referrals.

    

4. HL7 FHIR (Fast Healthcare Interoperability Resources)

   A newer standard designed for the web and mobile era.

   Uses modern technologies like RESTful APIs and JSON or XML formats.

   Focuses on simplified, fast, and scalable healthcare data exchange. 

Why HL7 Matters in Healthcare

• Interoperability

  HL7 allows different healthcare systems to talk to each other, ensuring that patient data flows securely and consistently across hospitals, clinics, labs, and pharmacies.

   

• Improved Patient Care

  By facilitating seamless data exchange, HL7 helps providers access comprehensive patient records, make informed decisions, and reduce errors.

   

• Administrative Efficiency

  Automated sharing of data such as insurance details, test results, and appointment schedules reduces manual entry and duplication, saving time and resources.

   

• Regulatory Compliance

  Many countries mandate the use of HL7 or similar standards for electronic health records and health information exchanges (HIEs).  

Common Use Cases for HL7

• Sending lab test results from a lab system to an EHR

• Sharing patient demographics between hospital departments

• Transmitting pharmacy prescriptions electronically

• Exchanging clinical notes between general practitioners and specialists

• Enabling secure, standardised data sharing in telehealth platforms 

Challenges and Considerations

• Complexity: Older HL7 versions (like V2) can be difficult to implement due to variability in interpretation.

• Customization: Many systems implement HL7 in slightly different ways, which may require custom integration.

• Evolving Standards: Transitioning to modern standards like HL7 FHIR requires updates to legacy systems and staff training.

HL7 is a cornerstone of healthcare interoperability, making it possible for different systems and providers to securely and efficiently exchange patient information. As healthcare continues to digitise, HL7, especially in its modern FHIR form, will play an even bigger role in connecting data, systems, and care providers around the world.  

HL7 and Faxing: How Online Fax Providers Fit In

Although HL7 standards are primarily used for digital health data exchange, many healthcare organizations still rely on faxing, especially for communicating with external providers, smaller clinics, or organizations not yet fully integrated into digital health ecosystems. Online fax providers like Notifyre play a critical role in bridging this gap between modern interoperability standards and traditional workflows.

Here’s how HL7 is relevant to fax and how some online fax services support this integration: 

1. Bridging Digital and Analog Systems 
   Even though HL7 is meant to help healthcare systems share information electronically, many doctors and hospitals still need to fax documents because of rules, laws, or older technology. Online fax services make it possible to send HL7-based documents safely by fax, even if the other side can’t receive them electronically.

    

2. HL7 Document Support 
   Formats like HL7 CDA are often used to create structured medical documents such as discharge summaries or referrals. These documents can be exported from EHR systems and sent as PDF attachments through online fax services, preserving compliance and data fidelity.

    

3. Integration Capabilities 
   Advanced online fax platforms like Notifyre offer fax API integration options that can work alongside HL7-compliant systems. For example, a hospital can trigger a fax automatically from its HL7-based system using Notifyre’s secure API, reducing manual intervention while maintaining workflow consistency.

    

4. Security and Compliance 
   HL7 often handles Protected Health Information (PHI), which is subject to strict data protection regulations like HIPAA. Online fax providers such as Notifyre are HIPAA-compliant and ISO-certified, providing encryption and secure transmission of health data.

    

5. Support for Hybrid Healthcare Environments 
   In real-world settings, not all healthcare providers use the same digital systems. Notifyre helps by turning digital health information into faxes, so everyone can receive the documents safely, no matter what system they use.