Fundamentals of FHIR

Fundamentals of FHIR

by: Katie D. McMillan, MPH and Karen Rourk, Duke Health Associate Chief Health Information Officer

If you live in the world of healthcare technology, you have likely heard about FHIR. There are some that say it's a silver bullet of interoperability, others that believe it to be overhyped. Where do you find information you can trust? We have put together some FAQs on FHIR that should help Duke Health and the broader health IT community understand some of the benefits, use cases, and limitations of FHIR. 

What IS FHIR? What is ITS history?

FHIR stands for Fast Healthcare Interoperability Resources. 

There are an estimated 96% of hospitals that use an electronic medical record to keep track of patient data. The conversion from paper to EHRs has changed the landscape of medical records and created the opportunity for mineable data. But with multiple players in the market (Epic, Cerner, AllScripts, Athena, and more) the challenge shifted from digitizing information to interoperability, sharing information, and making it useable. A data standard was needed. HL7, a non-profit dedicated to the exchange of health information, led the development of FHIR as a data sharing standard and set of APIs that could enable software to access information from the medical record for use by other applications. 

Ok wait, what's an API?

API stands for Application Programming Interface. An API is used to send data from one piece of software to another. 

Think of an alarm clock. The clock has three main parts: the physical face that tells the time, a cord, and a plug that goes into the wall. Electricity flows from the wall, through the plug and cord to the clock to power it and make the numbers appear on the clock face. An API is analogous to the cord on the clock, and the data that flows through an API is the electricity. APIs connect pieces of software and power the flow of data between them securely and efficiently. 

What are some use cases for FHIR?

Example of SMART Cardiac Risk app

There are numerous patient and provider apps have been created using FHIR. A catalogue of FHIR enabled apps is available on the SMART App Gallery site

Example Patient-Use Case: 

The Apple Health Record feature for iPhones pulls together a snapshot of a patient's medical record using data points accessible via FHIR and authentication through MyChart. Duke has made this feature available to their patients.

Example Provider-Use Case: 

The SMART Cardiac Risk app presents relevant patient vitals and lab measurements and the calculated Reynolds Risk Score, along with a succinct, patient-friendly explanation for each result. The app also offers simulation: the clinician (or patient) can make changes to one or more of the patient’s vitals or lab results to see how the patient’s current Reynolds Risk Score could be improved.


What data can I access using FHIR?

There are hundreds of resources at varying levels of maturity. Your ability to use them depends on the implementation of the hospital system. For example, Duke Health has the following resources available as part of the open.Epic implementation:

  • Patient

  • Provider

  • Allergies

  • Medications

  • Conditions

  • Observation (ex: labs, vitals)

  • Family History

  • Diagnostic Report

  • Immunization

  • Care Plans + Goals

  • Procedure

  • Device (implanted devices like a pace maker)

  • Encounter (where the visit took place, like at a clinic or a home health visit) - coming soon

  • Schedule - coming soon

Within each resource there are multiple data points. For example, Patient would include details about name, gender, date of birth, marital status, address and more. 

How does FHIR work best? 

FHIR works best pulling a single patient’s data. One patient using one app and accessing their own medical information or for a provider app accessing data for a particular patient and displaying it or combining with information from outside the app into a single view. 

Accessing one patient at a time is necessary because an app (mobile or web) needs a way to identify the patient in order to access their specific health record. Currently this is done via Epic authentication, so patient facing apps using FHIR require that the patient has a MyChart account and provider apps require access with their Epic credentials. 

FHIR is not a good tool for pulling together data on cohorts of patients. For example, the overhead processing for FHIR to download data on a group of 300 patients who all have the same medical condition could impact the EHR production performance. There are other ways to do this and the ACE or Maestro Care teams at Duke can assist with the best approach to access and utilize health record data. 

Can I use FHIR to write data back to the EHR?

This feature is not currently available with Epic, but there are plans to add this capability in the future. There are concerns around data integrity, use, and potential legal implications as any data added becomes part of the legal medical record. Over time these concerns will be addressed by multiple health systems and EHR vendors. Once this capability is enabled, each request to do so will be evaluated by Duke Health Technology Solutions and the appropriate clinical stakeholder group.  

This is an exciting time to be in health IT and tools like FHIR are enabling advances in our use of medical data. We hope you learned something! If you have more questions about FHIR contact


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