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Interoperability Toolkit (ITK) release 2.2

The Interoperability Toolkit (ITK) aims to standardise interoperability within both health and social care.

The ITK is a set of common specifications, frameworks and implementation guides to support interoperability within local organisations and across local health and social care communities.

Read the guide to see the different versions of the interoperability toolkit.

Part 1: architecture and core – plumbing systems together

The ITK 2.2 architecture documentation set has been re-organised and re-written to make it simple and easy to understand. This set is intended for a mixed technical audience of individuals within an organisation of all levels intending to develop ITK accredited systems, as well as those in the health and social care architecture communities.


ITK 2.2 architecture documentation set

The ITK accreditation process has been designed to be very straightforward and deliberately light touch, focusing very much on demonstrating technical conformance of the ITK interface against the relevant specifications and standards. The process is completely independent from both the standards / requirements bodies and the suppliers.

The Interoperability Toolkit (ITK) core pack offers guidance on common (or core) ITK artefacts and concepts, backed up by examples and development artefacts such as XML schema.

Interoperability Toolkit (ITK) core components

The core pack covers

  • services in terms of "business services" (transport independent service definitions). Also included are Distribution Envelope specific artefacts together with the WSDL files to help configure implementation.
  • distribution envelope includes element and attribute descriptions, scenario based envelope examples and the ITK Distribution Envelope schema. This section also has an overview of the profileId, which is an attribute of the Distribution Envelope.
  • The acknowledgement framework is a configurable request based framework, where acknowledgements are requested via the ITK distribution envelope's handling specifications. This section contains examples showing how acknowledgements are requested by setting handling specification values. Also included are detailed element and attribute descriptions, as well as schema definitions, for both the ITK infrastructure acknowledgement and the ITK business acknowledgement.
  • For metadata, this pack contains guidance for implementing XDS metadata for ITK correspondence payloads. The guidance contains detailed element and attribute descriptions as well as schema definitions and examples.

Part 2: Domain Message Specifications – messages over the plumbing

Each specific domain contains a technical specification which describes how the message is constructed (schema), the interaction flow of the message between two parties, configurable options within the distribution envelope which relate to the interaction, and also links to any associated specifications need for the implementation. 

Read more about the Transfer of Care Domain Message Specification on TRUD

Part 3: HL7 CDA sender and receiver requirements – common functional behaviour

The ITK domain message specifications contain many CDA profiles for specific use cases, for example ‘Transfer of Care: eDischarge’. To ensure common behaviours in both sending and receiving systems, a specification has been included within ITK2.2. This document covers the key requirements of ensure consist system behaviour, including a common error vocabulary, and a clear definition of CDA levels (1,2a, 2b, and 3). It should be noted that ITK conformance will state which CDA level an accredited sending system supports.

Read the ITK CDA sender and receiver requirements

Part 4: testing and accrediting an implementation

The NHS Digital ITK Conformance team offers support to all implementers of the specifications, through the provisioning of test tooling which simulates endpoints, and validates messages. As part of the offering, implementers can become ITK conformant to have their products listed on the ITK conformance catalogue. 

Last edited: 3 July 2019 3:15 pm