The interoperability is often associated with the capacity of exchanging information that belongs to different workflows in a distributed environment. In e-health, the implementation of interoperable systems has a direct impact on the access of medical services, the costs and the quality of those services. This paper summarizes the efforts of standardization done by a selected group of Europeans researchers in the healthcare domain. The assessment of this standardization effort is made through a study of its impact in 20 FP5 and FP6 European projects that address the healthcare domain. The objectives are identify the new trends on interoperability technologies and to point out the importance of approximate industrials and research institutes.