A Service Episode is a collection of events, aggregated during an interval bounded by start and stop times. A Service Episode is the context in which the treatment or management of an arbitrary subset of a Patient’s medical conditions occurs. The definition of the start time, stop time, and included events of a Service Episode is entirely arbitrary; it may include a single outpatient visit or a hospitalization, or extend over significant period of time, e.g., the duration of a pregnancy, or an oncology treatment regimen, or a cardiac episode from infarction through rehabilitation. A Service Episode may involve one or more Healthcare Organizations (administrative entities that authorize Healthcare Providers to provide services within their legal administrative domain, e.g. hospitals, private physician’s offices, multispecialty clinics, nursing homes).

A subset of Service Episode, the Visit, is the collection of events that fall under the accountability of a particular Healthcare Organization in a single facility. A Visit may be associated with one or more physical locations (e.g. different rooms, departments, or buildings) within the Healthcare Organization's definition of a facility, with admission and discharge diagnoses and with time boundaries of the visit.

Notes: 1. The Visit is a part of the Service Episode. The Service Episode describes several administrative aspects of healthcare, while the Visit is limited to the description of one visit of a Patient to a facility.

2. In the context of the Modality Worklist SOP Class, the attributes of the Service Episode are defined in the Visit modules.

3. The attributes for Visit often use the term “admission” for historical reasons, although a visit in an ambulatory clinic does not involve an admission as an in-patient.