10 Fast Healthcare Interoperability Resources Interview Questions and Answers

Fast Healthcare Interoperability Resources (FHIR) is a standard describing data formats and elements for exchanging electronic health records (EHR). Developed by Health Level Seven International (HL7), FHIR aims to simplify implementation without sacrificing information integrity. It leverages existing logical and theoretical models to provide a consistent, easy-to-implement, and rigorous mechanism for data exchange in healthcare environments.

This article offers a curated selection of interview questions designed to test your understanding and proficiency with FHIR. By reviewing these questions and their detailed answers, you will be better prepared to demonstrate your expertise in healthcare data interoperability and stand out in your upcoming interviews.

Fast Healthcare Interoperability Resources Interview Questions and Answers

1. Describe the basic structure of a FHIR resource and its key components.

FHIR (Fast Healthcare Interoperability Resources) is a standard for exchanging healthcare information electronically. It defines a set of “resources” that represent granular clinical concepts. These resources can be managed in isolation or aggregated into complex documents.

The basic structure of a FHIR resource includes the following key components:

• Resource Type: Each FHIR resource has a specific type, such as Patient, Observation, or Medication, defining its nature and purpose.
• Identifiers: Resources often include unique identifiers to ensure they can be distinctly recognized across different systems.
• Metadata: Each resource contains metadata providing additional context, such as the version, last update date, and language.
• Elements: Resources are composed of elements, which are the individual data points within the resource.
• References: Resources can reference other resources to create relationships.
• Extensions: FHIR allows for extensions to be added to resources to accommodate additional information not part of the standard specification.

2. Explain how you would create a custom extension for a FHIR resource. Provide an example.

FHIR is designed to enable interoperability between different healthcare systems. Sometimes, the standard FHIR resources do not cover all the specific needs of a particular use case. In such cases, custom extensions can be used to add additional information to FHIR resources.

To create a custom extension, define it with a URL and the value it holds.

Example:

{
  "resourceType": "Patient",
  "id": "example",
  "extension": [
    {
      "url": "http://example.org/fhir/StructureDefinition/custom-patient-birthplace",
      "valueString": "New York"
    }
  ],
  "name": [
    {
      "use": "official",
      "family": "Doe",
      "given": [
        "John"
      ]
    }
  ],
  "gender": "male",
  "birthDate": "1980-01-01"
}

In this example, a custom extension is added to the Patient resource to include the birthplace of the patient.

3. Describe how you would use a FHIR bundle to send multiple resources in a single transaction. Provide an example.

A FHIR bundle is a collection of resources sent together in a single transaction. This is useful in healthcare applications where multiple related resources need to be created, updated, or deleted in a single operation. A FHIR bundle can contain different types of resources and ensures that all resources are processed together, maintaining data consistency.

Example:

{
  "resourceType": "Bundle",
  "type": "transaction",
  "entry": [
    {
      "fullUrl": "urn:uuid:1",
      "resource": {
        "resourceType": "Patient",
        "id": "1",
        "name": [
          {
            "use": "official",
            "family": "Doe",
            "given": ["John"]
          }
        ]
      },
      "request": {
        "method": "POST",
        "url": "Patient"
      }
    },
    {
      "fullUrl": "urn:uuid:2",
      "resource": {
        "resourceType": "Observation",
        "id": "2",
        "status": "final",
        "code": {
          "coding": [
            {
              "system": "http://loinc.org",
              "code": "3141-9",
              "display": "Body weight"
            }
          ]
        },
        "subject": {
          "reference": "urn:uuid:1"
        },
        "valueQuantity": {
          "value": 70,
          "unit": "kg"
        }
      },
      "request": {
        "method": "POST",
        "url": "Observation"
      }
    }
  ]
}

In this example, the FHIR bundle contains a Patient resource and an Observation resource, with the Observation referencing the Patient.

4. Describe how OAuth2 and SMART on FHIR are used to secure FHIR APIs. Provide an example of an authorization flow.

OAuth2 is an authorization framework that enables applications to obtain limited access to user resources without exposing user credentials. SMART on FHIR extends OAuth2 to provide a standardized way to secure FHIR APIs, defining profiles and extensions to ensure secure access to FHIR resources.

Example of an authorization flow:

• The client application requests authorization from the user.
• The user is redirected to the authorization server, where they log in and grant access.
• The authorization server redirects the user back to the client application with an authorization code.
• The client application exchanges the authorization code for an access token.
• The client application uses the access token to access FHIR resources.

import requests

# Step 1: Redirect user to authorization server
auth_url = "https://authorization-server.com/auth"
client_id = "your_client_id"
redirect_uri = "https://your-app.com/callback"
scope = "openid profile user/*.*"
response_type = "code"

authorization_request = f"{auth_url}?client_id={client_id}&redirect_uri={redirect_uri}&scope={scope}&response_type={response_type}"
print("Go to the following URL to authorize:", authorization_request)

# Step 2: User logs in and grants access, then is redirected back with an authorization code
authorization_code = "received_authorization_code"

# Step 3: Exchange authorization code for access token
token_url = "https://authorization-server.com/token"
data = {
    "grant_type": "authorization_code",
    "code": authorization_code,
    "redirect_uri": redirect_uri,
    "client_id": client_id,
    "client_secret": "your_client_secret"
}

response = requests.post(token_url, data=data)
access_token = response.json().get("access_token")

# Step 4: Use access token to access FHIR resources
fhir_url = "https://fhir-server.com/Patient"
headers = {
    "Authorization": f"Bearer {access_token}"
}

response = requests.get(fhir_url, headers=headers)
print(response.json())

5. Explain how FHIR terminology services work and provide an example of how to use them to validate a code.

FHIR terminology services provide operations to interact with code systems and value sets, ensuring that codes used in healthcare data are valid and consistent with standards.

To validate a code using FHIR terminology services, send a request to a FHIR server with the code and the code system it belongs to.

Example:

import requests

def validate_code(code, system):
    url = "http://hapi.fhir.org/baseR4/CodeSystem/$validate-code"
    params = {
        "code": code,
        "system": system
    }
    response = requests.get(url, params=params)
    return response.json()

result = validate_code("12345", "http://loinc.org")
print(result)

In this example, we use the HAPI FHIR server to validate a code from the LOINC code system.

6. What is a FHIR implementation guide, and why is it important? Provide an example of how it is used.

A FHIR implementation guide is a document that outlines how to use FHIR standards to achieve specific healthcare interoperability goals. It includes instructions, constraints, and examples to ensure that different systems can communicate effectively.

For example, a FHIR implementation guide for electronic health records (EHR) might specify how to represent patient demographics, clinical observations, and medication information using FHIR resources. It would include constraints on the data elements, such as which fields are required, optional, or must follow specific coding systems.

7. Explain the importance of data provenance in FHIR and how it is implemented.

Data provenance in FHIR provides a record of the origin and history of data, ensuring that healthcare providers can trust the information they are using. Provenance information helps in auditing, compliance, and maintaining the integrity of the data.

In FHIR, data provenance is implemented using the Provenance resource. This resource captures information about the entity that created or modified a resource, the time at which the action occurred, and the reason for the action.

Example of a Provenance resource in FHIR:

{
  "resourceType": "Provenance",
  "target": [
    {
      "reference": "Patient/example"
    }
  ],
  "recorded": "2023-10-01T12:00:00Z",
  "agent": [
    {
      "who": {
        "reference": "Practitioner/example"
      },
      "onBehalfOf": {
        "reference": "Organization/example"
      }
    }
  ]
}

8. Describe the relationships between different FHIR resources and provide examples.

The relationships between different FHIR resources are essential for understanding how data is interconnected. Here are some key relationships:

• Patient and Observation: The Patient resource represents an individual receiving care, while the Observation resource contains measurements or assessments about the patient.
• Patient and Encounter: The Encounter resource represents an interaction between a patient and healthcare provider(s) for the purpose of providing healthcare services.
• Encounter and Observation: Observations are often made during an encounter.
• Practitioner and Encounter: The Practitioner resource represents an individual involved in the provision of healthcare services.

Example:

{
  "resourceType": "Observation",
  "id": "example-observation",
  "status": "final",
  "code": {
    "coding": [
      {
        "system": "http://loinc.org",
        "code": "29463-7",
        "display": "Body Weight"
      }
    ]
  },
  "subject": {
    "reference": "Patient/example-patient"
  },
  "encounter": {
    "reference": "Encounter/example-encounter"
  },
  "valueQuantity": {
    "value": 70,
    "unit": "kg"
  }
}

In this example, the Observation resource references both a Patient and an Encounter.

9. Outline the best practices for securing FHIR APIs beyond OAuth2 and SMART on FHIR.

When securing FHIR APIs beyond OAuth2 and SMART on FHIR, several best practices should be considered:

• Data Encryption: Ensure that all data, both in transit and at rest, is encrypted using strong encryption standards.
• Access Control: Implement fine-grained access control mechanisms to restrict access to sensitive data based on user roles and permissions.
• Audit Logging: Maintain comprehensive audit logs of all API interactions.
• Rate Limiting and Throttling: Implement rate limiting and throttling to prevent abuse and denial-of-service (DoS) attacks.
• Input Validation and Sanitization: Ensure that all input data is properly validated and sanitized to prevent injection attacks.
• Regular Security Assessments: Conduct regular security assessments, including vulnerability scanning and penetration testing.
• Secure API Gateway: Utilize a secure API gateway to manage and protect API traffic.

10. Provide examples of different use cases where FHIR has been successfully implemented to improve healthcare outcomes.

FHIR has been successfully implemented in various use cases to improve healthcare outcomes. Here are some examples:

• Electronic Health Record (EHR) Integration: FHIR has been used to integrate disparate EHR systems, allowing for seamless data exchange between different healthcare providers.
• Patient Portals: FHIR enables the development of patient portals that provide individuals with access to their health records.
• Clinical Decision Support Systems (CDSS): FHIR has been utilized to enhance CDSS by providing real-time access to patient data.
• Telehealth Services: FHIR supports telehealth by facilitating the exchange of patient data between remote healthcare providers and patients.
• Population Health Management: FHIR has been used to aggregate and analyze data from multiple sources to identify trends and patterns in population health.