HL7 ADT

To see the latest Compass V2 schema, please see Discovery Remote Subscriber Database Familiarisation#Data_Mapping

The Discovery Data Service (DDS) takes HL7 ADT messages from a number of suppliers, transforms the data into FHIR, and makes this available for subscriber use. This page provides an overview the HL7 ADT message types, structure, transform process, and the ADT -> FHIR -> Compass2 mappings.

Further segment level details are described in the article Publisher API HL7 Messages where details of cardinality are also given

Message Types

Publisher	Message Type	Message Name
Barts Health Homerton	ADT^A01	Admit / visit notification
Barts Health Homerton	ADT^A02	Transfer a patient
Barts Health Homerton	ADT^A03	Discharge/end visit
Barts Health Homerton	ADT^A04	Register a patient
Homerton	ADT^A05	Pre-admit a patient
Homerton	ADT^A06	Change an outpatient to an inpatient
Homerton	ADT^A07	Change an inpatient to an outpatient
Barts Health Homerton	ADT^A08	Update patient information
Barts Health	ADT^A11	Cancel admit/visit notification
Barts Health Homerton	ADT^A12	Cancel transfer
Barts Health Homerton	ADT^A13	Cancel discharge/end visit
Homerton	ADT^A14	Pending admit
Homerton	ADT^A17	Swap patients
Barts Health Homerton	ADT^A23	Delete a patient record
Homerton	ADT^A27	Cancel pending admit
Barts Health Homerton	ADT^A28	Add person information
Barts Health Homerton	ADT^A31	Update person information
Barts Health Homerton	ADT^A34	Merge patient information - patient ID only
Barts Health Homerton	ADT^A35	Merge patient information - account number only
Barts Health Homerton	ADT^A44	Move account information - patient account number

Message Structures

The messages types are grouped by their structure for transformation to FHIR, since this avoids a large amount of code repetition.

When saving FHIR to the Discovery store there are variations in handling of message types within the message structure groups.

The structures are as follows:

Structure A – Patient level messages

Applies to	Standard segments	Cerner custom segments
ADT^A01 (Admit/visit notification) ADT^A02 (Transfer a patient) ADT^A03 (Discharge/end visit) ADT^A04 (Register a patient) ADT^A05 (Pre-admit a patient) ADT^A06 (Change an outpatient to an inpatient) ADT^A07 (Change an inpatient to an outpatient) ADT^A08 (Update patient information) ADT^A11 (Cancel admit/visit notification) ADT^A12 (Cancel transfer) ADT^A13 (Cancel discharge/end visit) ADT^A14 (Pending admit) ADT^A23 (Delete a patient record)	MSH [1..1] Message header EVN [1..1]  Event information PID [1..1] Patient information PD1 [0..1] Additional demographics NK1 [0..*] Next of kin / associated parties PV1 [1..1] Patient visit information PV2 [0..1] Patient visit additional OBX [0..*] Obs (used by Homerton for misc. admin data) AL1 [0..*] Allergies ACC [0..*] Accident information DG1 [0..*] Diagnosis information NTE [0..*] Notes and comments	ZAL [0..*] Additional allergy information ZQA [0..1] Questionnaire information ZPI [0..1] Additional person information ZVI [0..1] Additional visit information

Structure B – Person level messages (without encounter information)

Applies to	Standard segments	Cerner custom segments
ADT^A28 (Add person information) ADT^A31 (Update person information)	MSH [1..1] Message header EVN [1..1] Event information PID [1..1] Patient information PD1 [0..1] Additional demographics NK1 [0..*] Next of kin / associated parties OBX [0..*] Obs (used by Homerton for misc. admin data) AL1 [0..*] Allergies NTE [0..*] Notes and comments	ZAL [0..*] Additional allergy information ZPI [0..1] Additional person information

Structure C – Swap patients

Applies to	Standard segments	Cerner custom segments
ADT^A17 (Swap patients)	MSH [1..1] Message header EVN [1..1] Event information PID [1..1] Patient information PV1 [1..1] Patient visit information PV2 [0..1] Patient visit additional OBX [0..*] Obs (used by Homerton for misc. admin data)	ZPI [0..1] Additional person information ZVI [0..1] Additional visit information

Structure D – Merge patient information

Applies to	Standard segments
A34 (Merge patient information) A44 (Move account information)	MSH [1..1] Message header EVN [1..1] Event information PID [1..1] Patient information PD1 [0..1] Additional demographics MRG [1..1] Merge information

Structure E – Merge account number

Applies to	Standard segments
A35 (Merge account number)	MSH [1..1] Message header EVN [1..1] Event information PID [1..1] Patient information PD1 [0..1] Additional demographics PV1 [1..1] Patient visit information MRG [1..1] Merge information

Transformation

The diagram below shows a simplified view of the HL7 to FHIR transform for structure A with the source HL7 segments on the left and target FHIR resources on the right.

Barts Health	Homerton
	As Barts Health plus NK1 and ZVI

The following sections show each transformation in detail, including field mappings.

Message Header

Barts Health	Homerton
Message Header (MSH)	Message Header (MSH) & Even Type (EVN)

MSH field mapping

Publisher	Field#	FieldName	FHIR Mapping	Extension
Barts Health Homerton	MSH.3	Sending application	MessageHeader.source.software
Barts Health Homerton	MSH.4	Sending facility	MessageHeader.source.name
Barts Health Homerton	MSH.5	Receiving application	MessageHeader.destination.extension	message-header-destination-software-extension
Barts Health Homerton	MSH.6	Receiving facility	MessageHeader.destination.name & MessageHeader.responsible
Barts Health Homerton	MSH.7	Message date/time	MessageHeader.timestamp
Barts Health Homerton	MSH.9	Message type	MessageHeader.event.code
Barts Health Homerton	MSH.10	Message control id	MessageHeader.extension	message-header-message-control-id-extension
Barts Health Homerton	MSH.12	Version ID	MessageHeader.event.version
Homerton	MSH.13	Sequence number	MessageHeader.extension	message-header-sequence-number-extension

EVN field mapping

Publisher	Field#	FieldName	FHIR Mapping
Homerton	EVN.5	Operator ID	MessageHeader.enterer & Practitioner.identifier & Practitioner.name

Patient

Barts Health Patient Identification (PID), & Patient Additional Demographic (PD1)

OR

Homerton Patient Identification (PID), Patient Additional Demographic (PD1), & Next of Kin (NK1) segments

PID field mapping

Publisher	Field#	FieldName	FHIR Mapping	Extension	Compass Schema Table	Field
Barts Health Homerton	PID.2	Patient ID	Patient.identifier		patient	nhs_number or null
Barts Health Homerton	PID.3	Patient Identifier List	Patient.identifier		patient	nhs_number or null
Barts Health	- PID.3.1	ID	Patient.identifier.value		patient	nhs_number or null
Barts Health	- PID.3.4	Assigning authority	Patient.identifier.system		–	–
Homerton	PID.4	Alternate PatientIidentifier	Patient.identifier		patient	nhs_number or null
Barts Health Homerton	PID.5	Patient Name	Patient.name		patient	first_names last_name
Barts Health	- PID.5.1	Family Name	Patient.name.family		patient	last_name
Barts Health	- PID.5.2	Given Name	Patient.name.given		patient	first_names
Barts Health	- PID.5.3	Middle Name	Patient.name.given		patient	first_names
Barts Health	- PID.5.5	Prefix	Patient.name.prefix		patient	title
Barts Health	- PID.5.7	Name Type Code	Patient.name.use		–	–
Barts Health Homerton	PID.7	Date/Time Of Birth	Patient.birthDate & Patient.extension	primarycare-contact-birth-time-extension	patient	date_of_birth
Barts Health Homerton	PID.8	Sex	Patient.gender		patient	gender_concept_id
Barts Health Homerton	PID.9	Patient Alias	Patient.name		–	–
Barts Health Homerton	PID.11	Patient Address	Patient.address		patient	current_address_id
Barts Health	- PID.11.1	Street Address	Patient.address.line		patient_address	address_line_1
Barts Health	- PID.11.2	Other Designation	Patient.address.line		patient_address	address_line_2
Barts Health	- PID.11.3	City	Patient.address.city		patient_address	city
Barts Health	- PID.11.5	Zip Or Postal Code	Patient.address.postalCode		patient_address	postcode
Barts Health	- PID.11.7	Address Type	Patient.address.use		patient_address	use_concept_id
Barts Health	- PID.11.8	Other Geographic Designation	Patient.address.line		patient_address	address_line_3
Barts Health	- PID.11.9	County/Parish Code	Patient.address.district		patient_address	ward_code local_authority_code
Barts Health Homerton	PID.13	Phone Number - Home	Patient.telecom		patient_contact	type_concept_id
Barts Health	- PID.13.1	Patient Number	Patient.telecom.value		patient_contact	value
Barts Health	- PID.13.2	Telecommunication Use Code	Patient.telecom.use		patient_contact	use_concept_id
Barts Health Homerton	PID.14	Phone Number - Business	Patient.telecom		patient_contact	type_concept_id
Barts Health	- PID.14.1	Patient Number	Patient.telecom.value		patient_contact	value
Barts Health	- PID.14.2	Telecommunication Use Code	Patient.telecom.use		patient_contact	use_concept_id
Barts Health Homerton	PID.15	Primary Language	Patient.communication.language		✗	✗
Barts Health Homerton	PID.16	Marital Status	Patient.maritalStatus		✗	✗
Barts Health Homerton	PID.17	Religion	Patient.extension	primarycare-religion-category-extension	✗	✗
Barts Health Homerton	PID.18	Patient Account Number	Patient.identifier		✗	✗
Barts Health Homerton	PID.22	Ethnic Group	Patient.extension	primarycare-ethnic-category-extension	patient	ethnic_code_concept_id
Barts Health Homerton	PID.29	Patient Death Date and Time	Patient.deceased		patient	date_of_death
Barts Health Homerton	PID.30	Patient Death Indicator	Patient.deceased		–	–

✗ = Data available but not published to Compass schema
– = Not applicable

PD1 field mapping

Publisher	Field#	FieldName	FHIR Mapping	Compass Schema Table	Field
Barts Health Homerton	PD1.3	Patient primary facility	Patient.careProvider& Organization	patient	organization_id
Barts Health	- PD1.3.3	ID number	Organization.identifier.value	organization	ods_code
Barts Health Homerton	PD1.4	Patient primary care provider	Patient.careProvider& Practitioner	patient	registered_practice_organization_id
Barts Health	- PD1.4.1	ID number	Practitioner.identifier.value	practitioner	gmc_code
Barts Health	- PD1.4.2	Family name	Practitioner.name.family	practitioner	name
Barts Health	- PD1.4.3	Given name	Practitioner.name.given	practitioner	name
Barts Health	- PD1.4.9	Assigning authority	Practitioner.identifier.system	practitioner	organization_id

NK1 field mapping

Publisher	Field#	FieldName	FHIR Mapping	Extension	Compass Schema Table	Field
Homerton	NK1.2	Name	Patient.contact.name		✗	✗
Homerton	NK1.3	Relationship	Patient.contact.relationship		✗	✗
Homerton	NK1.4	Address	Patient.contact.address		✗	✗
Homerton	NK1.5	Phone number	Patient.contact.telecom.value		✗	✗
Homerton	NK1.6	Business phone number	Patient.contact.telecom.value		✗	✗
Homerton	NK1.7	Contact role	Patient.contact.extension	primarycare-contact-role-category-extension	✗	✗
Homerton	NK1.20	Primary language	Patient.contact.extension	primarycare-contact-main-language-category-extension	✗	✗

✗ = Data available but not published to Compass schema
Encounter

Barts Health Patient Visit (PV1), Patient Visit - additional (PV2), & Event Type (EVN)

OR

Homerton Patient Visit (PV1), Patient Visit - additional (PV2), & Additional Visit Information (ZVI) segments

Note - Each ADT message containing a PV1 segment (i.e. Structure A messages) results in a new FHIR Encounter resource being created.

The newly created FHIR Encounter is linked to an EpisodeOfCare resource based on the PV1’s Visit Number (this is carried in the Attendance Number field).

If the PV1 Visit Number is new – i.e. has not previously been seen by Discovery – this causes a new EpisodeOfCare resource to be created.

If the PV1 Attendance Number has previously been seen by Discovery, then the Encounter is linked to the existing EpisodeOfCare.

PV1 field mapping

Publisher	Field#	FieldName	FHIR Mapping	Extension	Compass Schema Table	Field
Barts Health Homerton	PV1.2	Patient class	Encounter.class		encounter	core_concept_id non_core_concept_id admission_method
Barts Health	PV1.3	Assigned patient location	Encounter.location & Location		encounter location	institution_location_id id
Barts Health	- PV1.3.1	Point of Care	Encounter.location		encounter	institution_location_id
Barts Health	- PV1.3.2	Room	Encounter.location		encounter	institution_location_id
Barts Health	- PV1.3.3	Bed	Encounter.location		encounter	institution_location_id
Barts Health	- PV1.3.4	Facility	Encounter.location Encounter.location		encounter	institution_location_id
Barts Health	- PV1.3.7	Building	Encounter.location		encounter	institution_location_id
Homerton	PV1.4	Admission type	Encounter.extension	encounter-admission-type	✗	✗
Homerton	PV1.6	Prior patient location	Encounter.location& Location		✗	✗
Barts Health Homerton	PV1.7	Attending doctor	Encounter.participant & Practitioner		encounter practitioner	practitioner_id id
Barts Health	- PV1.7.1	ID number	Practitioner.identifier.value		practitioner	gmc_code
Barts Health	- PV1.7.2	Family name	Practitioner.name.family		practitioner	name
Barts Health	- PV1.7.3	Given name	Practitioner.name.given		practitioner	name
Barts Health	- PV1.7.9	Assigning authority	Practitioner.identifier.system		practitioner	organization_id
Barts Health Homerton	PV1.8	Referring doctor	Encounter.participant & Practitioner		✗	✗
Barts Health	- PV1.8.1	ID number	Practitioner.identifier.value		✗	✗
Barts Health	- PV1.8.2	Family name	Practitioner.name.family		✗	✗
Barts Health	- PV1.8.3	Given name	Practitioner.name.given		✗	✗
Barts Health	- PV1.8.9	Assigning authority	Practitioner.identifier.system		✗	✗
Homerton	PV1.9	Consulting doctor	Encounter.participant& Practitioner		✗	✗
Barts Health Homerton	PV1.10	Hospital service	Encounter.serviceProvider& Organization		encounter organization	organization_id service_provider_organization_id id
Homerton	PV1.14	Admit source	Encounter.hospitalization.origin		✗	✗
Homerton	PV1.17	Admitting doctor	Encounter.participant & Practitioner		✗	✗
Barts Health Homerton	PV1.18	Patient type	Encounter.type		encounter	core_concept_id non_core_concept_id
Barts Health Homerton	PV1.19	Visit number	EpisodeOfCare.identifier		episode_of_care	id
Barts Health Homerton	PV1.36	Discharge disposition	Encounter.hospitalization.dischargeDisposition		✗	✗
Barts Health Homerton	PV1.37	Discharged to location	Encounter.hospitalization.destination		✗	✗
Homerton	PV1.39	Servicing facility	Encounter.managingOrganization		–	–
Barts Health Homerton	PV1.41	Account status	Encounter.status		episode_of_care	registration_status_concept_id
Barts Health Homerton	PV1.44	Admit date/time	Encounter.statusHistory.start		encounter encounter_event	clinical_effective_date
Barts Health Homerton	PV1.45	Discharge date/time	Encounter.statusHistory.end		encounter encounter_event	end_date clinical_effective_date
Homerton	PV1.50	Alternate visit ID	Encounter.identifier		✗	✗
Homerton	PV1.52	Other healthcare provider	Encounter.participant& Practitioner		✗	✗

PV2 field mapping

Publisher	Field#	FieldName	FHIR Mapping	Compass Schema Table	Field
Barts Health Homerton	PV2.3	Admit reason	Encounter.reason	✗	✗
Homerton	PV2.4	Transfer reason	Encounter.reason	✗	✗
Barts Health Homerton	PV2.8	Expected admit date/time	Encounter.statusHistory.start	✗	✗
Homerton	PV2.9	Expected discharge date/time	Encounter.statusHistory.end	✗	✗

EVN field mapping

Publisher	Field#	FieldName	FHIR Mapping	Extension	Compass Schema Table	Field
Barts Health	EVN.2	Recorded date/time	Encounter.extension	primarycare-recorded-date-extension	encounter	date_recorded
Homerton	EVN.5	Operator ID	MessageHeader.enterer & Practitioner.identifier & Practitioner.name		✗	✗

ZVI field mapping

Publisher	Field#	FieldName	FHIR Mapping	Compass Schema Table	Field
Homerton	ZVI.9	Admit mode	Encounter.hospitalization.admitSource	✗	✗
Homerton	ZVI.15	Assign to location date/time	Encounter.location.period	✗	✗

✗ = Data available but not published to Compass schema
– = Not applicable