In this specification, this is represented as a positive or negative time offset from the start date and time of the appointment. The duration for which the service or resource is needed for the appointment The duration for which the service or resource is required for the appointment describes how long the service or resource is needed to complete the appointment. By adding the duration to the start date and time, the end date and time can be calculated for the required resource or service within the activity. Other attributes further describe services and resources. These attributes are communicated, as necessary, in transactions between applications.
Appointments are instances of the performance of a service or the use of a resource.
Appointments can describe scheduled activities related to patients in a healthcare setting, or they can describe scheduled activities wholly unrelated to patients. In its simplest form, an appointment consists of one service or resource reserved for a period of time, for a specific reason. More complex activities involve multiple services or resources, or parent-child relationships to other appointments. Except in special circumstances, the code is assigned by the placer application upon making an initial scheduling request. This concept is similar in practice to the placer order number found in Chapter 4, Order Entry.