Extensions

Extensions Defined in This Guide

These define extensions to FHIR resources created for use within the Resource Profiles defined in this guide. Extension specific business rules can be found below the table.

Note: Extensions applied to the HealthcareService payload (e.g., AccessInstructions, DeliveryMethod, Facet, IsPrimary, Media, UsageLicense) have not been included in this version of the guide. Future versions may expand the guidance related to interacting with endpoints and payloads for HealthcareService information (either as a section in this guide or through a separate guide). In the meantime, implementers in need of further guidance on the HealthcareService characteristics and design practices should refer to the HealthcareService Directories Section under the Business Rules page the Ontario eServices v0.11.1 Guide.

Routing Options Business Rules

Some referral processes may ask the referrer to provide some data that impacts the performer's automated referral processing rules. The rules for how a performer processes their referrals can be unique to the performer. Some examples include routing based on:

• The type of referrer (from the hospital, primary care, out of province, etc...)
• The patient's Postal Code FSA (e.g., K8N, L0L, etc...)
• The first letter of the patient's last name (e.g., A-J, K-Z)

To handle this, use the Routing Options extension, which is included in both the ServiceRequest AND MessageHeader (for add-service-request event) resources. By also including the extension in the MessageHeader, it makes it easier for implementers to find the key routing-related data fields without needing to dig further into the referral payload.

Note: When the eReferral process is combined with a service directory, the directory should be able to publish the valueSet of referral options that are available for a selected service.

Patient Present Location Business Rules

Sometimes a referral needs to communicate where the patient is at the time of the referral (e.g., in Ward X of Hospital Y), which may be different from the patient's home address. To communicate this, use the PatientPresentLocation extension, which references a Location resource.

Present location can be nested using Location.partOf to communicate locations with multiple levels, e.g., Location.partOf > Location for WardX > HospitalY.

Extensions Defined Externally

These define extensions to FHIR resources created for use within the Resource Profiles defined in this guide. Extension specific business rules can be found below the table.

Gender, Birth Sex, & Gender Identity Business Rules

Patient.gender is to be used to specify the observed patient gender at the time of the referral (regardless of the gender presentation at birth). This is also referred to as "administrative gender", which is the gender that the patient is considered to have for administration and record keeping purposes. This property is often used as an input to patient matching algorithms.

Due to its importance in patient matching algorithms, gender is a must support element, although it is not mandatory (0..1) on the profile. In the case where a referral does not need to know gender, set "Patient.gender" = "unknown". If sending an administrative gender that is not in the value set (e.g. "X" non-binary), that MAY be sent as "Other" with an appropriate extension sent with the proper value.​

Note that the FHIR Patient resource documentation discusses patient.gender in depth.

Regarding more detailed tracking of gender identity there are ongoing discussions in the standards community, this implementation guide is waiting on a community consensus. The HL7 Gender Harmony IG project provides in-depth guidance on recording sex and gender. If more detailed gender values are required, an implementer may consider using the FHIR individual-genderIdentity extension. To specify birth sex, consider using the US Core birthSex extension or the CIHI IRRS FHIR Implementation Guide.