Hi Michael,
You have raised a very pertinent question. I think paper-based patient record systems exist in most of the countries though they may not be standardized or capture relevant data. These data are in general fed into the national information systems in aggregate form. So when a country decides to implement a electronic medical record system it can also provide required aggregate data provided there is an agreement on the data to be collected and reported in relation to the said health objective.Until then, the focus should remain on aggregate systems.
But before getting into the interoperability details, I think it is important to deliberate on the system design issues which is driven by the requirements of its users. An important component of the design is system architecture which should align with the health goals and offers standardization, flexibility and scale to meet evolving health care information needs.
Also interoperability should not be discussed strictly in its technical sense which refers to automated information exchange rather it should include relatively less resource intensive options such as data import/export.
