Question 3. What aspects of a NHIN could be national in scope vs. local or regional? Please describe the roles of entities at those levels.

• The Health Information Environment will take shape incrementally, over time. Its development will include both "top-down" (i.e., nationally-defined) policies and standards, and "bottom-up" (i.e., community and market-driven) initiatives.
• Both local and national strategies are needed. Most healthcare is local, and a great deal of information access occurs in a patientıs own community. At the same time, many patients receive care, coverage, and benefits across multiple regions; also, the US population is highly mobile, whether moving across state lines from home to work or from winter to summer homes. Many multi-institution networks, that effectively comprise local health information infrastructures, already exist and must be accommodated.
• In general our proposed model for the Health Information Environment is decentralized and regionally driven. It is desirable to leave to the local systems those things best handled locally, while specifying at a national level those things required as universal in order to allow for interoperability among regional systems. The Common Framework, comprised of the essential security and interoperability standards required to assure secure Internet transmission or patient matching methods, must be national, so that all participating institutions can connect to one another securely and without unworkable variation.