📁 3. Deciphering FHIR buzzwords

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In this learning unit, you’ll explore the essential terms and concepts behind FHIR, which stands for Fast Healthcare Interoperability Resources — a vital standard in healthcare technology.

You’ll learn what interoperability means, why FHIR is considered “fast,” and how resources are key to its framework. We’ll also cover the 80% rule that shapes FHIR’s design, the concepts of profiling and extensibility for customization and flexibility, and the different exchange paradigms that facilitate data sharing.

By the end, you’ll be familiar with the core FHIR terms and ready to dive deeper into the world of healthcare interoperability. Let’s get started!

Subsections of 📁 3. Deciphering FHIR buzzwords

Chapter 8

📖 FHIR is a standard

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FHIR is a standard.

FHIR (Fast Healthcare Interoperability Resources) is a healthcare standard.

A standard is a set of guidelines or specifications designed for a particular field or industry. The goal of a standard is to ensure information consistency and compatibility between different healthcare systems and applications.

Everyday examples for standards are:

  • the ISO codes for currencies like U.S. Dollar (USD), Euro (EUR), Japanese Yen (JPY).

  • Standard Time zones (UTC - Coordinated Universal Time)

  • standardized closing sizes (XS, S, L, M, XL, XXL).

Using a standard means to follow a common framework to achieve predictable and reliable outcomes: Standardized clothing sizes help consumers find the right fit across different brands. ISO codes for currencies ensure consistency and accuracy in international financial transactions. Finally, standard time zones based on Coordinated Universal Time (UTC) synchronize clocks and schedules worldwide, which is essential for smooth global communication and travel.

FHIR standardizes healthcare data formats to ensure seamless and accurate information exchange between different systems.

With FHIR, accessing a patient record ensures that the data is consistent and reliable. When you send data to another healthcare provider using FHIR, you can trust that they will receive the same information, with no alterations or loss.

FHIR meets several typical key criteria for standards in the IT context:

1. Consensus based development

FHIR is developed by HL7 (Health level 7 International: https://www.hl7.org/ ), a global authority on standards for electronic health data. The development process involves collaboration between a wide range of stakeholders, including healthcare providers, technology vendors and regulators.

A key role in this process is played HL7 Work groups (https://www.hl7.org/Special/committees/, https://hl7.org/fhir/resourcelist.html ), where experts from different areas come together and discuss, develop and refine aspects of FHIR that are relevant to their field of expertise. For example, the Patient care work group (https://www.hl7.org/Special/committees/patientcare/index.cfm ) is responsible for FHIR resources like AllergyIntolerance, Condition, CarePlan.

2. Technical specifications

FHIR provides a comprehensive set of technical specifications that describe how information can be exchanged between different systems. These specifications are all documented on the FHIR website.

3. Seamless data exchange

The ultimate goal of FHIR is to provide standardized formats and rules for data exchange such that on its way from one system to another, the health care data integrity is preserved and the information can easily be read by the recipient.

This is realized by providing a common framework and language for exchanging data. FHIR ensures that information can be shared across diverse platforms and applications like electronic healthcare records, devices, and hospital IT systems. This is realized by two core features:

  1. Common standardized format: The structure and content of a given concept is defined in dedicated resources in a specified format.

  2. Formalized rules on how to exchange information, for example via a Restful API.

4. Flexibility and Scalability

FHIR is designed to be adaptable and scalable. It supports a wide range of use cases, from simple data sharing to complex, large-scale integration projects. Scalability is particularly crucial for healthcare organizations, as it ensures that as their needs and operations expand, FHIR can continue to facilitate efficient and secure data exchange. Whether a small clinic or a large hospital network, FHIR’s scalability allows these institutions to maintain seamless interoperability as they grow, integrate new systems, and handle increasing volumes of patient data.

5. Quality and Compliance

FHIR includes guidelines and rules that ensure the quality, accuracy, and security of exchanging medical information. It helps organizations comply with regulatory requirements for data exchange and privacy, such as HIPAA1 in the USA.

Chapter 9

📖 The F.H.I.R. Acronym

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What is an acronym?

An acronym is a word formed by taking the initial letters of a series of words or phrases and combining them into a single term. The letters typically represent the key words in the phrase, and the resulting acronym is often easier to say or remember than the full phrase.

For example:

  • NASA: National Aeronautics and Space Administration
  • RADAR: Radio Detection and Ranging
  • LASER: Light Amplification by Stimulated Emission of Radiation

Acronyms are commonly used to simplify complex terms, making them more manageable in conversation and writing. They are particularly prevalent in technical fields, organizations, and government agencies.

Some acronyms become so widely used that they are recognized as words in their own right (like “laser or “scuba”), while others are used more as shorthand in specific contexts.

FHIR stands for Fast Healthcare Interoperability Resources. From this acronym we get several more hints about its nature than just it being a standard, with all implications that come with that.

FHIR claims to be FAST

The meaning of FAST in this context is that FHIR is fast to implement.

To implement something refers to the process of putting a plan into effect. It involves taking the steps that are necessary to carry out the project in a practical, real-world setting.

FHIR is fast to implement because it uses modern web standards like Restful APIs, JSON and XML. Developers are already familiar with them because of they are widespread used all industries. Also, the docs are user friendly and focus on helping with implementation.

FHIR being fast can also apply to performance. The architecture of FHIR is built to handle high volumes of data and transactions, enabling swift access and retrieval of healthcare information.

FHIR is Healthcare-specific

FHIR is tailored for the healthcare industry.

Interoperability

The term interoperability appears to have originated within the context of the military and defense industry in the mid 20th century. It was used to describe the ability of different weapons systems, units or forces to work together effectively.

By the 1970s and 1980s, interoperability had become a common term in IT and telecommunications.

In healthcare, it means that doctors, nurses, hospitals, apps, pharmacies all can exchange and understand each other's medical records even if they use different types of computer systems. This helps everyone work together to improve healthcare for their patients.

In the introduction for non-developers we already mentioned some every-day examples for (missing) interoperability like different units for temperature and distance, or incompatibility of a Microsoft Office Presentation in Libre Office impress.

These everyday examples illustrate how lack of interoperability can lead to confusion and errors. But when it comes to more critical fields like aerospace, healthcare, or defense, the consequences of poor interoperability can be far more severe.

Incompatibility Examples

Real historical examples show that lacking interoperability, whether due to incompatible units, software errors, or outdated standards, can have dramatic and sometimes deadly consequences - expand the paragraph to learn more.

Interoperability issues can lead to serious and even catastrophic consequences. To illustrate the importance of consistent and standardized data across systems, here are five historical examples where a lack of interoperability resulted in major failures:

1. Mars Climate Orbiter

In 1999, NASA’s Mars Climate Orbiter was lost in space due to a simple unit conversion error. One team used metric units (newtons), while another used imperial units (pounds-force) for the spacecraft’s navigation software. The lack of standardization led to the spacecraft deviating from its intended path and burning up in Mars’ atmosphere. A failure to ensure data compatibility resulted in a $125 million mission loss.

2. Therac-25 Radiation Therapy Machine

The Therac-25 was a radiation therapy machine that, in the 1980s, caused severe radiation overdoses due to a software error. The lack of proper interoperability and communication between software modules led to malfunctions in the machine’s safety systems. This resulted in the machine delivering radiation doses hundreds of times higher than intended, causing serious injuries and deaths.

3. Airbus A400M

In 2015, an Airbus A400M military transport aircraft crashed during a test flight, killing four crew members. The accident was traced back to software configuration issues that caused the engines to shut down unexpectedly. Different teams used incompatible software formats that were not properly integrated, leading to a critical failure in the aircraft’s control systems.

4. Patriot Missile Failure in the 1991 Gulf War

During the 1991 Gulf War, a Patriot missile defense system failed to intercept a Scud missile, resulting in the deaths of 28 American soldiers. The failure was due to a software bug caused by a timing error that arose from incompatibility between the system’s internal clock and the actual passage of time. The system was off by 0.34 seconds, enough to miss the target by hundreds of meters.

5. Year 2000 Problem (Y2K Bug)

The Y2K bug was a computer flaw that resulted from the practice of using two-digit numbers to represent years (e.g., “99” for 1999). As the year 2000 approached, there were fears that systems would interpret “00” as 1900, causing widespread software failures. The issue highlighted the need for consistent data standards and proper planning for long-term interoperability in computer systems.

Resources

The central role of FHIR is played by resources. They are predefined data structures that represent different healthcare entities.

Examples are:

For each resource, specific properties are defined. For example, a patient has a name, an address, an identifier, a birthdate, a gender and other characteristics.

These properties are like fields in a form that can be filled with the patient’s data. But unlike a paper form, a patient resource provides more flexibility and mechanisms to check if the data is correct or missing. Moreover, it is readable and understandable by a computer.

All information that is exchanged is packaged in a FHIR resource.

Patient data, medication data, terminologies, even technical info like the capability statement of a server that says what it can offer, are resources.

You can imagine as separate paper forms for different aspects of health care.

You will learn more about Resources in this learning unit.

Chapter 10

📖 FHIR's 80% rule

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The 80% rule is a decisive strategic approach to handle the huge amount of diversity of healthcare data. Because of the sheer volume of different use cases and perspectives in the healthcare sector, it is hard to agree on data structures. FHIR resources that satisfy all participants for a nephrologist specialize on kidney transplantations, the exact time of birth of a patient will seem to be of no importance, while for the neonatologist it will be very relevant.

To capture the ethnicity of a patient is not important or even adequate in Germany, but of clinical relevance for the interpretation of certain lab parameters or risk factors in the US.

To include all possible properties for all resources would lead to very big constructs that would be hard to navigate. Therefore, the 80% rule states that only the 80% most important commonly agreed upon properties are included in the resource. Or put differently, a resource should be usable for 80% of. All use cases in all sub sectors of the healthcare industry. The remaining 20% of special use cases are not represented by the predefined resources.

Note:

The opposite approach would be to include all possible elements that any use case would ever need. This approach is followed the openEHR, an open standard for managing and sharing electronic health records (EHRs).

Chapter 11

📖 Profiling

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Profiling

The definition of resources in FHIR is not only about the content of a resource, but also about the structure and relationship of the elements.

The cardinality states how often. An element can appear in a resource and if it is mandatory and not.

Examples are 0..1 or 1..1 and so on.

Profiling is the action of adjusting a resource to your needs.

For example in your case, if in your case the birth date may be necessary, then you change 01211.

The result of profiling is an adjusted resource. We call it a profile.

Profiles are what is used in implementations. Resources are the definitions from the specification. Although some people don't make a clear distinction between the two terms.

Video: FHIR Profiling in 100 seconds.

Chapter 12

📖 Extensibility

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FHIR resources can be extended. As mentioned, the 80% rule limits their applicability to 80% of the most relevant use cases. To overcome this limitation. and to be able to use the resource for a use case of the remaining 20%, extensions can be added.

For example, in the US Core Specification, the Ethnicity extension is part of the patient resource. Extensions are resources on their own that can be added to a profile.

Video: FHIR Extensbility in 100 seconds.

Chapter 13

📖 Exchange Paradigms

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The various possibilities of exchanging FHIR resources are referred to as the FHIR exchange paradigms. There are six (?) of them:

RESTful API (Representational State Transfer):

The most common exchange paradigm in FHIR is the FHIR RESTful API1, where resources are accessed and manipulated using standard HTTP methods like GET, POST, PUT, DELETE, etc. Each resource has a unique URL, and operations are performed on these resources via HTTP requests. Supports searching, updating, and retrieving resources.

Messaging:

FHIR supports a message-based exchange paradigm where data is sent in the form of a message. Typically used for event-driven exchanges, such as sending alerts or notifications between systems. Messages contain a bundle of resources and are sent as a single transaction.

Documents:

FHIR documents are a static, narrative-driven bundle of resources that can be exchanged. These documents are used when a complete, self-contained package of information is needed, such as a discharge summary or a clinical report.

Unlike other paradigms, documents are meant to be read as a complete story and not interacted with piecemeal.

Services:

In this paradigm, FHIR can be used to define and invoke services. This includes clinical decision support services or other operations that are performed as a service call, with FHIR defining the request and response formats. Examples include operations like $validate, $lookup, or $expand.

Subscriptions:

FHIR supports a subscription model where clients can subscribe to certain events (like updates to a resource), and the server notifies them when these events occur. This is useful for real-time data updates, such as monitoring patient vitals or receiving updates when a patient’s status changes.

Batch/Transaction:

In this paradigm, multiple FHIR resources are bundled together and sent in a single HTTP request.

Batch

A group of independent operations that the server processesindividually.

Transaction

A group of operations that the server processes as a single atomic operation, where either all operations succeed, or none do.

You'll learn about the exchange paradigms in Chapter 9.

Video: FHIR Exchange Paradigms in 100 seconds.

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Official FHIR RESTful API Documentation

Official Messaging Documentation

Official Documents Documentation

Official Services Documentation

Official Subscriptions Documentation