The Electronic Patient Record (EPR) is a fundamental part of health information technology and its use is growing quickly. There is an urgent need to record and trust events related with healthcare procedures. Accountability is, therefore, essential but still very difficult to achieve in terms of information security. This paper suggests an accountability model suitable for healthcare environments and describes how the model can be efficiently realized using secure hardware. This approach can be applied across heterogeneous infrastructures providing a separation of duties between people, processes and organizations whilst ensuring the confidentiality and integrity of information.