Digital Referral Prescription Implementation Guide
1.0.0 - STU Belgium flag

Digital Referral Prescription Implementation Guide, published by eHealth Platform. This guide is not an authorized publication; it is the continuous build for version 1.0.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/hl7-be/referral/ and changes regularly. See the Directory of published versions

Telemonitoring

Telemonitoring

A telemonitoring prescription instructs the recording of one or more vital parameters (blood pressure, heart rate, weight, …) over a defined period, and defines the rules under which the receiving system should raise an alert (absolute thresholds, sustained breaches, significant changes over time).

This page describes the artifacts defined for telemonitoring:

Logical model

RemoteMonitoringPrescription is a specialization of BeReferralPrescription: it inherits the common prescription fields and adds the elements needed to express what to measure, how often, and when to alert.

BeReferralPrescriptionidentifier 1..1 IdentifiershortCode 1..1 CodeableConceptrecordedDate 1..1 dateTimecreationDate 1..1 dateTimepatient 1..1 Identifierauthor 1..1 Identifierstatus 1..1 CodeableConceptstatusReason 0..1 CodeableConceptcareRequested 1..1 CodeableConceptdiscipline 1..1 CodeableConceptdescription 0..1 CodeableConcepttype 1..1 CodeableConceptoriginRequestId 0..1 IdentifiervalidityStartDate 1..1 dateTimevalidityEndDate 1..1 dateTimeproblem 0..* CodeableConceptbodyLocation 0..* CodeableConcept RemoteMonitoringPrescriptionmeasurementSchedule 0..1 Timing "Monitoring duration and measurement frequency "monitoringPlan 1..* "Parameter to monitor"parameter 1..1 CodeableConcept "What is measured (LOINC/SNOMED)"baseline 0..1 Reference(Observation) "Baseline/reference measurement (e.g. reference weight)"threshold 0..* "Absolute threshold rule"range 1..1 Range "Numeric threshold (max and/or min) with unit"sustainedFor 0..1 Duration "Trigger only if breached for this long"maxIncrease 0..* Ratio "Max allowed increase per time window (e.g. 2 kg / 7 d)"maxDecrease 0..* Ratio "Max allowed decrease per time window (e.g. 3 kg / 14 d) "Inherits all fields of BeReferralPrescription.In the FHIR profile, maxIncrease + maxDecreasecollapse into a single signed `change` Ratio(positive numerator = increase, negative = decrease).
RemoteMonitoringPrescription as a specialization of BeReferralPrescription

The type of monitoring service is carried on the inherited careRequested element using SNOMED CT codes (e.g. 135840009 Blood pressure monitoring). The parameter being measured in monitoringPlan.parameter uses LOINC codes (e.g. 8480-6 systolic BP, 8462-4 diastolic BP). SNOMED has no separate code for systolic vs diastolic BP monitoring — both fall under 135840009, and the distinction is expressed per-parameter via the LOINC codes and their respective thresholds.

Profile: BeReferralServiceRequestTelemonitoring

The telemonitoring prescription is a profile of BeReferralServiceRequest. The mapping from the logical model is:

Logical model ServiceRequest element
identifier identifier
patient subject
validityStartDate / validityEndDate extension[validity].valuePeriod.start / .end
careRequested code
measurementSchedule occurrenceTiming (bounds + frequency)
monitoringPlan extension[monitoringPlan] (BeTelemonitoringPlan), one instance per monitored parameter

All monitoring rules are presently carried inline on the ServiceRequest, so each prescription is self-contained.

Extension: BeTelemonitoringPlan

Each instance of the BeTelemonitoringPlan extension describes the rules for one monitored parameter. A blood pressure prescription therefore typically has two instances: one for systolic and one for diastolic.

Sub-extension Card. Type Meaning
parameter 1..1 CodeableConcept What is measured (LOINC), e.g. 29463-7 Body weight, 8480-6 Systolic BP, 8462-4 Diastolic BP, 8867-4 Heart rate
baseline 0..1 Reference(Observation) Baseline/reference measurement the rules are evaluated against, e.g. a reference weight of 80 kg
threshold 0..* complex Absolute threshold rule
threshold.range 1..1 Range Numeric threshold (min and/or max) with unit
threshold.sustainedFor 0..1 Duration Only trigger if the breach lasts this long (e.g. 3 days)
change 0..* Ratio Maximum allowed change per time window
Baseline measurement

Some rules, for example weight gain, need a reference value to be evaluated. This reference is an Observation (e.g. body weight = 80 kg) referenced from baseline. The referenced Observation SHOULD be an independent resource available to the receiving system, and therefore SHOULD NOT be a contained resource.

Rate-of-change rules

The logical model’s maxIncrease and maxDecrease collapse into a single signed change Ratio:

  • a positive numerator expresses a maximum increase (e.g. +2 kg / 7 d)
  • a negative numerator expresses a maximum decrease (e.g. -3 kg / 14 d)

Searching telemonitoring prescriptions

Some systems need to retrieve, in a single query, all ServiceRequests that are either proposals (intent = proposal) or telemonitoring prescriptions (a given prescriptionType in category). Standard FHIR search combines different search parameters with AND, so this cannot be expressed with the intent and category search parameters.

The Intent OR Prescription Type search parameter (intent-or-prescription-type) indexes both ServiceRequest.intent and the prescriptionType slice of ServiceRequest.category. Multiple values are combined with OR:

GET [base]/ServiceRequest?intent-or-prescription-type=proposal,telemonitoring-chronic-heart-failure

Values can be qualified with their system to avoid ambiguity:

  • http://hl7.org/fhir/request-intent|proposal
  • https://www.ehealth.fgov.be/standards/fhir/terminology/CodeSystem/be-cs-prescription-type|telemonitoring-chronic-heart-failure

Servers must load the SearchParameter (with status active) and reindex their existing data before the parameter returns results.