This article from the Healthcare Information and Management Systems Society (HIMSS) blog is the first of a three-part posting concerning the establishment of an HIE, particularly for patients who are deemed vulnerable due to lack of regular access to the healthcare delivery system and the presence of one or more chronic diseases. It suggests the demographic and clinical data elements that should be part of the dataset captured for the HIE.  It also mentions the complexity of identifying the various collection points (systems) that would be used to gather that data.