Interoperability is integrated connectivity. Interoperability enables data and information generated by one system to be accessed and (re-)used in a meaningful way by another system, whether or not the latter system is based on different technologies.

Interopability in computerised healthcare information systems lags far behind other (arguably less complex and variable) domains such as finance and transport. Many implemented health information technologies, such as electronic patient records, have tended to be local, proprietary and insular. Many systems in use weren't designed to communicate with others (whether inside or outside individual health provider organisations), so don't.

However, interopability, using open standards to support information and data exchange, has become a very significant issue for health information technology developers and implementers. It is probably the major concern of all national governments implementing or promoting the implementation of national health information networks and infrastructures.

Interoperability covers health and patient information, clinical knowledge and workflow, and technical matters such as architecture, messaging, interfacing knowledge and data representation, and security (data privacy, confidentiality, individual and organisation identifiers ...). Standards designed to support interoperability and national policy documents are covered in more detail elsewhere on OpenClinical (see links below). These include standards for communication, messaging, data transfer (DICOM for medical images, HL7 for electronic patient referrals, lab. requests and results); data representation standards (ASTM Continuity of Care Record, HL7 Clinical Document Architecture; medical terminologies and classifications (representing clinical data, drugs, lab. tests ...) electronic patient record architecture, structure, format (EHRcom, openEHR ...).

The Institute of Electrical and Electronics Engineers (IEEE, USA) defines interoperability as:

"the ability of two or more systems or components to exchange information and to use the information that has been exchanged". [IEEE-USA]

In Europe, IDABC - Interoperable Delivery of European eGovernment Services to public Administrations, Businesses and Citizens - offers the following similar definition (edited for clarity):

"Interoperability means the ability of information and communication technology (ICT) systems ... to exchange data and enable the sharing of information and knowledge." [IDABC]

The National Alliance for Health Information Technology (NAHIT, USA) expands a little on the above definitions:

"In healthcare, interoperability is the ability of different information technology systems and software applications to communicate, to exchange data accurately, effectively, and consistently, and to use the information that has been exchanged. " [NAHIT]

For health professionals:

• Improve access to health record data and health information anytime, anywhere.

For patients:

• Improve quality and safety of care by improving data exchange, the quality of data flow and access to information by health professionals thereby potentially reducing errors.

For health managers:

• Improve data collection and facilitate statistical and economic analysis.

For health researchers:

• Improve and increase the availability of medical data.

For the healthcare technology industry:

• Improve access to the healthcare market for more companies (SMEs in particular who may be limited in their ability to provide technologies which can integrate with an organisation's legacy systems).

• Without interoperability, fundamental data and information such as patient records can't easily be shared across and sometimes within enterprises.
• Achieving interoperability in a domain where information technologies, where they have been deployed in routine practice, may not have been designed to support it.
• Many standards to support interoperability are only just now being developed - after many HIT systems have been installed.
• Where HIT standards do exist they may also compete, making interoperability more difficult to achieve.
• A lot of computerised clinical data are stored in ageing legacy systems in proprietary formats which are dificult for other systems to access, re-represent and transfer for (re)use. (The use of proprietary formats may also lock customers into specific information systems.)
• Implementation of interoperable health information systems may require a high degree of technical expertise not readily available to small organisations in particular.

Connected Health: Quality and Safety for European Citizens. Unit ICT for Health in collaboration with the i2010 sub-group on eHealth and the eHealth stakeholders’ group. Commission of the European Communities, Information Society & Media DG, 2006 []   [OC]

"This paper outlines priority issues which must be pursued vigorously in order to reach all of these health systems goals - improve patient safety, encourage well-informed citizens and patients on health matters, and create high-quality health systems and services - and, at the same time, face international competition in the eHealth sector." "The main reasons for accelerating the introduction of interoperable eHealth solutions in a collaborative and coordinated way in Europe are the increasing mobility of European citizens, the aging population and the empowerment of citizens, the continuity of care and the creation of a bigger, European-wide market for many health applications and technologies."

Commission on Systemic Interoperability. Ending the Document Game: Connecting and Transforming Your Healthcare Through Information Technology, NLM/NIH/HHS, 2005. [endingthedocumentgame.gov]   [OC]

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