ADT in Canada

In Canada, your system sends HL7 v2 admission, discharge, and transfer (ADT) messages to Health Gorilla. Health Gorilla uses them to keep each patient's record accurate and up to date as the patient moves between facilities.

The Canadian ADT service works differently from the United States ADT Data Service: there's no patient roster to maintain, and Health Gorilla doesn't send notifications back to your system. Your system sends ADT messages, and Health Gorilla returns an HL7 v2 acknowledgment for each one.

Patient Identifiers

Include both of these identifiers in the PID segment of every ADT message, each tagged with its identifier type code:

• Health Card Number (HCN): identifier type HCN. Identifies the patient across facilities.
• Medical Record Number (MRN): identifier type PT. Identifies the patient within the facility that assigned it.

Health Gorilla uses these identifiers, along with the patient's name and date of birth, to match each message to the correct patient. A message for a patient Health Gorilla hasn't matched creates a new record, and a message that matches an existing patient updates it. Health Gorilla needs a first name, last name, and date of birth to create or update a patient from a message.

Supported ADT Event Types

Health Gorilla accepts the following HL7 v2 ADT event types in Canada. If you send an event type outside this set, Health Gorilla returns an HL7 v2 acknowledgment rejecting the message.

Canada accepts the A40 patient merge event. The A29 patient delete event is accepted in the United States only.

Patient Merge (A40)

An A40 message merges two patient records when your system identifies a duplicate, so the patient's information stays consolidated. To send one, identify the primary patient in the PID segment and the prior, duplicate patient in the MRG segment, and set the event reason code to indicate a merge.

Health Gorilla acknowledges each A40 message: an application accept when the merge is applied, or an application reject when it can't match the duplicate patient from the MRG segment or the primary patient from the PID segment. If you replay an A40 for a patient that's already merged, Health Gorilla returns an application reject rather than merging the records again, because the prior record no longer exists.

After a merge, the primary patient's identifiers are used going forward, the primary record is updated with any demographics in the A40 message, and the duplicate patient's information is consolidated under the primary patient. The merge applies only within Health Gorilla and doesn't change records in your system or in a provincial registry.