The Ambulance Data Set (ADS) is split into four clear sections.
The first section is the "Header", and contains only the Submitting Organisation Code. This section is mandated.
The second section contains details of the "Call". Each call into the Ambulance Service generates an individual data set, even if calls are for the same incident. Call details must be present in the ADS. Call details also covers the call triage, the incident response times and the Emergency Operations Centre Clinical Review.
The third section contains the details of the "Response". There will be a Response section within the ADS for each response within the incident. This means that the Response details repeat for each response made. Response details include response times and episode outcome times.
The final section contains "Patient Contact" details. There may be many patient contacts per response, and a patient contact is related to its relevant response details. Patient contact details are at the individual patient level. Patient contact includes patient demographics, patient response details, patient information, injury information, patient assessment, medication, observations, diagnoses, conveying outcome, safeguarding and public health information.
The FHIR design for the MVP is to use the Communication resource to hold the Header and Call details. There will be a number of extensions added to cater for the complexity of the Ambulance Data Set data.
The Response details are modelled using the Encounter resource, and AmbulanceResponseVehicle-Location resource. FHIR recommends that response vehicles are modelled as Locations. There will be a Encounter instance per response per patient encounter (as the Encounter resource only allows one patient per Encounter). For example, if a Call generated a Response of 2 Ambulances to an Incident, and Ambulance 1 treated one patient, and Ambulance 2 treated two patients, the data set would have 3 Encounters (this would repeat some Encounter details).
The patient demographic details of the Patient Contact are held in the Patient (in the MVP, the NHS Number and Date of Birth). If the NHS Number and Date of Birth are not captured, there won't be a UKCore-Patient resource present. Other Patient Contact details for the MVP relate to the CAD conveying destination. These details are only present where a patient is conveyed. These details are modelled using the UKCore-ADS-Encounter.hospitalization.destination reference link to Receiving-Location (which is where the conveying type and ODS code is found).