1. A messaging system for routing clinical messages, said messaging system comprising: an event handler that: receives one or more inbound messages, including one or more worklist items, from one or more event sources; stores the worklist items in an event database; and, generates and communicates outbound messages for one or more worklist items in the event database that need to be acted upon, as determined by one or more rules; and a standardized protocol to represent the inbound messages and the outbound messages.