2.2.4 Patient timeline

When patients arrive at the hospital, and during their course of their stay, they can be transferred between different units, sent to the operating room for surgery, sent to the floor for recovering or undergo other procedures. To better describe these events, Figure 2.5 shows an excerpt from a discharge summary for a typical patient.

$\parbox{0.8\textwidth }{ \caption[Even... ...mmary, describing typical events during the patient stay in the hospital. } }$

Figure 2.6 is the visual representation of the events presented in Figure 2.5. We can identify the following events:

Hospital admission

:
A hospital admission, covers the period from the patient's admission to the hospital, until the patient's discharge from the hospital. It includes any visits to different wards (such emergency room, regular floor, and even different stays in an ICU room).

Patient admissions are recorded in the admissions table. As well as recording the Subject_ID of the admitted patient, each admission has a unique identifier (Hadm_ID) and an admission and discharge time.

Figure 2.7) shows the relationship between the admission table and other tables in the database.

ICU Stay

:
An ICU stay is a combination of one or more ICU census events that are separated by 24 hours or less.

ICU census event

:
Each time a patient enters or leaves a particular care unit, an event is recorded into the database in the table censusevents. Each of these events (identified by the column census_id), contain the time and date of entrance and exit of the care unit, the current unit the patient was hosted, the destination care unit the patient was transferred to, and the length of stay in the ICU room for that particular event.

$\parbox{0.8\textwidth }{ \caption[Hosp... ...zation timeline]{Typical events during the patient hospitalization period.} }$

Figure 2.7: Relationship between a hospital admission and other database tables.