Health Information Exchanges (HIE) enables the electronic sharing of health-related information among organizations. HIEs are used as the intermediary to centralize information and control access to it. The notion of a unified version of a patients medical record is fiction, writes Dr. Andrew Hammond. Hammond: EHR doesnt provide the full benefits of meaningful use unless the EHR follows the patient. He says HIE is made for the cloud, but there are trade-offs between distributed and central models.”]