The resource bundles are useful for a variety of different reasons, including:
– Returning a set of resources that meet some criteria as part of a server operation
– Returning a set of versions of resources as part of the history operation on a server
– Sending a set of resources as part of a message exchange
– Grouping a self-contained set of resources to act as an exchangeable and persistable collection with clinical integrity – e.g. a clinical document
– Creating/updating/deleting a set of resources on a server as a single operation (including doing so as a single atomic transaction)
– Storing a collection of resources
There are two ways to collect resources together for transport and persistence purposes – contained resources, and bundles. There is an important difference between the two:
– Contained resources are “in” the container resource – they can only ever be interpreted and/or changed in the context of the container
– A bundle is a collection of resources that can have an independent existence – for example, they might also be accessed directly using the RESTful API
In addition to these two technical mechanisms, there are three administrative and infrastructure resources which also support grouping of content. These resources do not contain resources directly, but instead, use [Reference] to point to the grouped resources:
– The List resource – Enumerates a flat collection of resources and provides features for managing the collection. While a particular List instance may represent a “snapshot”, from a business process perspective the notion of “List” is dynamic – items are added and removed over time. The list resource references other resources. Lists may be curated and have specific business meaning.
– The Group resource – Defines a group of specific people, animals, devices, etc. by enumerating them, or by describing qualities that group members have. The group resource refers to other resources, possibly implicitly. Groups are intended to be acted upon or observed as a whole; e.g. performing therapy on a group, calculating risk for a group, etc. This resource will commonly be used for public health (e.g. describing an at-risk population), clinical trials (e.g. defining a test subject pool) and similar purposes.
– The Composition resource – Defines a set of healthcare-related information that is assembled together into a single logical document that provides a single coherent statement of meaning, establishes its own context and that has clinical attestation with regard to who is making the statement. The composition resource provides the basic structure of an FHIR document. The full content of the document is expressed using a Bundle. Compositions will often reference Lists as the focus of particular sections.
These three resources represent meaningful groupings of the resources they refer to (e.g. a discharge medication List, a Group of participants for a clinical trial, a set of resources that form a signed document), while a Bundle is merely is a container for resources used for transfer and storage. This list is not exhaustive; other resources also provide grouping functionality.
Fast Healthcare Interoperability Resources (FHIR) is a draft standard describing data formats and elements (known as “resources”) and an application programming interface (API) for exchanging electronic health records. The standard was created by the Health Level Seven International (HL7) health-care standards organization.
Its goal is to facilitate interoperation between legacy healthcare systems, to make it easy to provide healthcare information to healthcare providers and individuals on a wide variety of devices from computers to tablets to cell phones, and to allow third-party application developers to provide medical applications which can be easily integrated into existing systems.
FHIR provides an alternative to document-centric approaches by directly exposing discrete data elements as services. For example, basic elements of healthcare like patients, admissions, diagnostic reports and medications can each be retrieved and manipulated via their own resource URLs (Uniform Resource Locators). FHIR was supported at an American Medical Informatics Association meeting by many EHR (Electronic Health Record) vendors which value its open and extensible nature.