The following document provides a developer an overview of how to interact with the Ignite FHIR APIs, and specifically Scheduling (GET /Slot, POST /Appointment, and GET /Appointment).

• It is assumed access to the API has already been ascertained.
• Developer has downloaded Postman.

For our use case, we have interest as an external application developer to:

1. Identify open schedule slots for a specific provider, and slot type
2. Book an appointment on behalf of a consumer
3. Review that we've successfully booked the appointment

In our test environment, we will use the following variables to interact with the API:

• Patient Name: Wilma Smart
• Patient ID: 4342008
• Slot Type: General Medicine
• Slot Type Coding: http://snomed.info/sct
• Slot Type Code: 394581000
• Practitioner Name: Carter, Kristen Cerner
• Practitioner ID: 605926

We must first identify the schedules that are open so that we can book on behalf of our consumer user. We can search by:

• Slot Type
• Schedule Actor
• Location
• Start

As an example API call, structured to search the FHIR endpoint by a specific Slot Type, a Start year, and with a specific Practitioner, I will return all applicable, open slots that can be booked. https://{{endpoint}}.{{environment}}.com/dstu2/{{tenantId}}/Slot?slot-type={{slotType}}&start={{year}}&_count=20&schedule.actor=Practitioner/{{practitionerId}}

In my example, against the FHIR test environment, this is my resulting API call: https://fhir-ehr.sandboxcerner.com/dstu2/0b8a0111-e8e6-4c26-a91c-5069cbc6b1ca/Slot?slot-type=http%3A%2F%2Fsnomed.info%2Fsct%7C408443003&schedule.actor=Practitioner%2F605926&start=2020&_count=20

The API yields the following result, one of many open slots:

"entry": [{
        "fullUrl": "https://fhir-ehr.sandboxcerner.com/dstu2/0b8a0111-e8e6-4c26-a91c-5069cbc6b1ca/Slot/5038373-4048296-7731127-330",
        "resource": {
            "resourceType": "Slot",
            "id": "5038373-4048296-7731127-330",
            "meta": {
                "versionId": "0",
                "lastUpdated": "2019-03-04T22:07:30.000Z"
            },
            "text": {
                "status": "generated",
                "div": "<div><p><b>Slot</b></p><p><b>Type</b>: Office Visit - Follow Up</p><p><b>Start</b>: Jan  7, 2020  7:30 P.M. UTC</p><p><b>End</b>: Jan  7, 2020  8:00 P.M. UTC</p><p><b>Status</b>: Free</p></div>"
            },
            "extension": [{
                "url": "https://fhir-ehr.cerner.com/dstu2/StructureDefinition/scheduling-location",
                "valueReference": {
                    "reference": "Location/4048296"
                }
            }],
            "type": {
                "coding": [{
                        "system": "http://snomed.info/sct",
                        "code": "408443003",
                        "display": "General medical practice",
                        "userSelected": false
                    },
                    {
                        "system": "https://fhir.cerner.com/0b8a0111-e8e6-4c26-a91c-5069cbc6b1ca/codeSet/14249",
                        "code": "5038373",
                        "display": "Office Visit - Follow Up",
                        "userSelected": true
                    }
                ],
                "text": "Office Visit - Follow Up"
            },
            "schedule": {
                "reference": "Schedule/5038373-4048296-7731127-330"
            },
            "freeBusyType": "free",
            "start": "2020-01-07T19:30:00.000Z",
            "end": "2020-01-07T20:00:00.000Z"
        },
        "search": {
            "mode": "match"
        }
    },

The most critical element in this response, is the Slot.id value: 5038373-4048296-7731127-330. It is the primary identifier used when booking the appointment, against the POST /Appointment resource.

Now that we've identified an open slot, 5038373-4048296-7731127-330, let's book.

Our API request will look like the following:

• POST https://{{endpoint}}.{{environment}}.com/dstu2/{{tenantId}}/Appointment/

In this specific example, against the test environment:

• POST https://fhir-ehr.sandboxcerner.com/dstu2/0b8a0111-e8e6-4c26-a91c-5069cbc6b1ca/Appointment/

Our API request headers will follow what is found at fhir.cerner.com. For posterity:

• Authorization:
• Accept: application/json+fhir
• Content-Type: application/json+fhir

Let's compose our POST /Appointment payload. A few key variables to build:

• Appointment.slot.reference: Slot/{{slotId}}
• Appointment.participant.actor.reference: Patient/{{patientId}}
• Appointment.participant.actor.display: {{patientFamilyName}}, {{patientGivenName}}

Our body of the POST will look as such:

{
  "resourceType": "Appointment",
  "slot": [
    {
      "reference": "Slot/5038373-4048296-7731127-330"
    }
  ],
  "participant": [
    {
      "actor": {
        "reference": "Patient/4342008",
        "display": "Smart, Wilma"
      },
      "status": "needs-action"
    }
  ],
  "status": "proposed"
}