Abctract:
The availability of medical care data for authorized clinicians and nurses is expected to increase quality and effectivity and to reduce costs in the health care sector. Providing a national infrastructure for exchange of medical information in EHRs has been a point in the national agenda for health informatics for more than a decade.
Interoperability is regarded as a vital success factor. The success is measured by the ability to exchange information between EHR’s in the 5 Regions of Denmark.
The National Patient Index (NPI) addresses this issue by the use of the integration profile, specified for this purpose, namely the ”Integrating the Healthcare Enterprise (IHE) Cross enterprise Document Sharing (XDS)”.

This work asks the question how NPI will be a relevant step towards semantic interoperability.

The question seeks to be answered by literature investigation of how IHE / XDS standard works on the three levels of ALT-model (Application, Logic, Technique), which acts as a general model for the HER-system.

The conclusion is that IHE / XDS is operating solely on a technical level. The standard works content-neutral, ie. the exchanged information is not exposed to any mapping, translation or interpretation. By virtue of a common language and culture NPI will be confusingly similar to functional interoperability. True semantic interoperability, that is a prerequisite for international information exchange, remains a yet unsolved challenge.