The acute medical unit model: A characterisation based upon the National Health Service in Scotland.

Background: Acute medical units (AMUs) receive the majority of acute medical patients presenting to hospital as an emergency in the United Kingdom (UK) and in other international settings. They have emerged as a result of local service innovation in the context of a limited evidence base. As such, the AMU model is not well characterised in terms of its boundaries, patient populations and components of care.