The standard 'Healthcare Information Systems Architecture' and the DHE middleware.

The integration and evolution of existing systems represents one of the most urgent priorities of health care information systems in order to allow the whole organisation to meet the increasing clinical organisational and managerial needs. This paper discusses how an open architecture, based on the introduction of a middleware of common health care-specific services not only reduces the effort necessary for allowing existing systems to interwork, but also automatically establishes a functional and information basis common to the whole organisation, on top of which also new applications can be rapidly developed, natively integrated with the rest of the system. Such architecture has been already formalised through the European standard, defined by the CEN/TC251 prENV 12967-1 'Architecture for Health care Information Systems' (CEN prENV 12967-1 'Health care Information Systems Architecture'). Thanks to the availability of industrial products conforming to the standard, the effectiveness and the validity of this approach has been already demonstrated in practice. For example, through the Hansa collaboration hospitals and industries from countries of the Western and Eastern Europe, as well as of the Middle East use the same industrial middleware (i.e. 'The DHE middleware-Information view'-SPRI, 1998, 'The DHE middleware-Functional view'-SPRI, 1998) for integrating existing systems as well as for developing new applications.