Order Catalog Implementation Guide
0.1.0 - CI Build

Order Catalog Implementation Guide, published by HL7 International - Orders and Observations Work Group. This is not an authorized publication; it is the continuous build for version 0.1.0). This version is based on the current content of https://github.com/HL7/fhir-order-catalog/ and changes regularly. See the Directory of published versions

Order Catalog Home Page

The scope of the current ballot is limited to the "laboratory service content" of this IG.
Pages which are excluded from this ballot are signaled as such by a note to balloters at the top of the page.

Introduction to this guide

This implementation guide for sharing order catalogs is based on FHIR R4. Its scope is international (aka universal realm).

An order catalog exposes a homogeneous collection of healthcare items that can be ordered or selected by practitioners to support the course of healthcare delivery. These homogeneous healthcare items may represent services, products, devices or knowledge artifacts such as order sets, for instance. Each item specifies its purpose, describes how it should be ordered and/or used, and characterizes the outcomes that one can expect from its usage.

Examples of catalogs include order sets catalog, evidence based CDS content, laboratory test compendium, medication formulary, catalog of medical devices.

This universal realm implementation guide specifies the methods and artifacts based on the FHIR standard, to enable the sharing of catalogs of healthcare items across practitioners and organizations. The methods such as browsing, searching, retrieval, or maintaining the content, are common regarless of the catagory of catalog at hand: product, service, clinical knowledge... Some of the artifacts, like the one representing the catalog as a whole, are also common to all categories of catalogs. Other artifacts are specific to the category of items (medication, device, order set, diagnostic service ...) exposed by the catalog.

Considering these commonalities and specificities, building a common guidance for implementing any kind of catalog of healthcare items in FHIR has been deemed the most valuable proposition to implementers. Hence this unique Order Catalog Implementation Guide, which aims to cover all categories of catalogs of healthcare items. The use cases and artifacts (profiles, extensions, semantic resources) that are specific to a particular category of catalog will be placed under the responsibility of the HL7 Working Group defining the base resources for this category.

Project and sponsoring background

This IG is one of the product deliverables of project Ordering Service Interface Specification Project #1010, which is sponsored by Orders & Observations WG, and co-sponsored by Clinical Decision Support WG, Pharmacy WG, Imaging Integration WG and Service Oriented Architecture WG. The intention is that each work group contributes on its domain of expertise, to this cross-domain FHIR IG.

Purpose of order catalogs

A catalog provides reference data, which aggregates requirements and guidance of usage for the items of the catalog, from multiple sources: regulatory, clinical knowledge, organizational (based on the organization of the provider of the items). These reference data are assembled under the stewardship of the catalog custodian: an organization liable for building and sharing the catalog, and maintaining it over time.

Catalogs are most often shared on servers which make them accessible to the practitioners through their IT systems or applications (e.g. EHR, EMR, CPOE, apps, LIS, Pharmacy system ...) Client applications may interact with a catalog server to:

  • browse through entries of the catalog and retrieve items of interest together with the detailed instructions and guidance related to the usage of these items,
  • import the full catalog or a part of it (e.g. import the recent updates),
  • administer the content of the catalog: add/update/retire items and/or supporting resources.

Catalogs may also be exported in part or in whole to the consumer's system, using the FHIR messaging framework


Scopes of order catalogs and roles involved

Order catalogs have varied scopes, sizes, ownerships, stewardships and targetted consumers and jurisdictions. For instance an order catalog might expose the medical devices of a particular manufacturer to the potential users of these devices in a country. Another catalog might consolidate all the medical devices that are approved for use in healthcare throughout the European Union market. Another example of order catalog would be a drug formulary listing the medicinal products that are available for prescription in a particular hospital. A broader catalog of medicinal product might include all the medications authorized to the national market of a country. These examples illustrate various scopes and sizes of catalogs:

  • some catalogs may expose a huge number of items, and yet the FHIR resources that implement them must have a reasonable size, which does not hamper the management (creation, update, query, retrieval) of these resources ;
  • some catalogs are scoped for use within a single organization, while others address multiple organizations (or even jurisdictions) of potential consumers.

These examples also illustrate these roles involved in catalog interactions:

  • Catalog consumer: A system using the content of the catalog in its own local operations in healthcare (e.g. order entry of health products or services, or application of knowledge artifacts).
  • Catalog custodian: A system maintaining over time the catalog as a shareable object accessible by consumers through a FHIR interface.
  • Catalog owner: A system owning the content of the catalog.

The roles of custodian and owner may belong to a single organization and in that case, be combined in a single system. Conversely, for some of the examples above these roles may be played by two distinct organizations, each with its own system, in which case, FHIR interactions are needed between these two roles to administer the content of the shared catalog.

The interactions between those three roles are described in the Interaction Framework of this guide.


Technical Overview

The design choices presented here respect the flexibility requirements listed above.

In the FHIR standard, an order catalog as a whole is represented by an instance of the Composition resource, which conveys the general properties of the catalog (e.g. custodian, title, period of validity, type of content), and each item of the catalog is represented by a definitional resource, possibly associated with a set of supporting resources providing further details on this item. Two alternative methods are usable to bind the catalog as a whole to its items.

  1. The catalog references its items from its Composition.section.entry elements. This method constrains the Composition resource with the Catalog profile.
  2. Each definitional resource representing an item references the Composition resource. The Composition resource in this case acts as the header of the catalog. This method constrains the Composition resource with the CatalogHeader profile.
Methods for binding catalogs and their items

The catalog server must choose one of the two methods, and cannot mix the two methods for one catalog. Usable for catalogs of any size, the second method is in particular more appropriate for large catalogs because it makes the administration of the content easier. In particular, adding a new item or retiring an item does not impose any update to the Composition resource representing the catalog as a whole.

Walkthrough

The main sections of this IG are:

  • Use cases
    • Laboratory services - lists the use cases for compendium of laboratory diagnostic services.
    • Order sets - lists the use cases for library of order sets.
    • Medications - lists the use cases for catalog of drugs.
    • Devices - lists the use cases for catalog of devices.
  • Specifications
    • Laboratory services - specifies the FHIR resources implemented by a compendium of laboratory diagnostic services.
    • Order sets - specifies the FHIR resources implemented by a library of order sets.
    • Medications - specifies the FHIR resources implemented by a catalog of drugs, including medication formularies.
    • Devices - specifies the FHIR resources implemented by a catalog of devices.
  • Interaction Framework for all kinds of catalogs
  • Examples
    • Laboratory services - presents examples for compendia of laboratory diagnostic services.
    • Order sets - presents examples for libraries of order sets.
    • Medications - presents examples for catalogs of drugs.
    • Devices - presents examples for catalogs of devices.
  • Building blocks & assets
    • Artifact Index - provides all the detailed artifacts built for this implementation guide: semantic resources, profiles, extensions, examples.
    • Downloads - Allows downloading a copy of the artifacts of this implementation guide and other useful information.

Authors and Contributors

Role Name Organization
Primary Editor Fran├žois Macary Phast
Primary Editor Rob Hausam Hausam Consulting LLC
Contributor Freida Hall Quest Diagnostics
Contributor Gary Randman Quest Diagnostics
Contributor Kathy Walsh LabCorp
Contributor Andrea Pitkus U of Wisconsin