The inputevents table
Table source: MetaVision ICU database.
Table purpose: Input data for patients.
Number of rows: 7,643,978
- patients on
- admissions on
- icustays on
- d_items on
The original source database recorded input data using two tables: RANGESIGNALS and ORDERENTRY. These tables do not appear in MIMIC as they have been merged to form the INPUTEVENTS table. RANGESIGNALS contains recorded data elements which last for a fixed period of time. Furthermore, the RANGESIGNALS table recorded information for each component of the drug separately. For example, for a norepinephrine administration there would be two components: a main order component (norepinephrine) and a solution component (NaCl). The
ENDTIME of RANGESIGNALS indicated when the drug started and finished. Any change in the drug rate would result in the current infusion ending, and a new
STARTTIME being created.
Let’s examine an example of a patient being given norepinephrine.
STARTTIME for the solution (NaCl) and the drug (norepinephrine) would be 18:20. The rate of the drug is 1 mcg/kg/min, and the rate of the solution is 10 mL/hr. The nurse decides to increase the drug rate at 18:25 to 2 mcg/kg/min. As a result, the
ENDTIME for the two rows corresponding to the solution (NaCl and norepinephrine) is set to 18:25. Two new rows are generated with a
STARTTIME of 18:25. These two new rows would continue until either (i) the drug rate was changed or (ii) the drug was delivery was discontinued. The
ORDERID column is used to group drug delivery with rate of delivery. In this case, we have NaCl and norepinephrine in the same bag delivered at the same time - as a result their
ORDERID is the same (8003). When the rate is changed, a new
ORDERID is generated (8020). The column
LINKORDERID can be used to link this drug across all administrations, even when the rate is changed. Note also that
LINKORDERID is always equal to the first
ORDERID which occurs for the solution, as demonstrated in the example above.
- For Metavision data, there is no concept of a volume in the database: only a
RATE. All inputs are recorded with a
ENDTIME. As a result, the volumes in the database for Metavision patients are derived from the rates. Furthermore, exact start and stop times for the drugs are easily deducible.
- A bolus will be listed as ending one minute after it started, i.e.
STARTTIME+ 1 minute
|Name||Postgres data type|
Identifiers which specify the patient:
subject_id is unique to a patient,
hadm_id is unique to a patient hospital stay and
stay_id is unique to a patient ICU stay.
ENDTIME record the start and end time of an input/output event.
Identifier for a single measurement type in the database. Each row associated with one
ITEMID which corresponds to an instantiation of the same measurement (e.g. norepinephrine).
ITEMID values are all above 220000. Since this data only contains data from MetaVision, it only contains
ITEMID above 220000 (see here for details about MetaVision)
AMOUNTUOM list the amount of a drug or substance administered to the patient either between the
RATEUOM list the rate at which the drug or substance was administered to the patient either between the
STORETIME records the time at which an observation was manually input or manually validated by a member of the clinical staff.
ORDERID links multiple items contained in the same solution together. For example, when a solution of noradrenaline and normal saline is administered both noradrenaline and normal saline occur on distinct rows but will have the same
LINKORDERID links the same order across multiple instantiations: for example, if the rate of delivery for the solution with noradrenaline and normal saline is changed, two new rows which share the same new
ORDERID will be generated, but the
LINKORDERID will be the same.
ORDERCATEGORYNAME, SECONDARYORDERCATEGORYNAME, ORDERCOMPONENTTYPEDESCRIPTION, ORDERCATEGORYDESCRIPTION
These columns provide higher level information about the order the medication/solution is a part of. Categories represent the type of administration, while the
ORDERCOMPONENTTYPEDESCRIPTION describes the role of the substance in the solution (i.e. main order parameter, additive, or mixed solution)
The patient weight in kilograms.
Intravenous administrations are usually given by hanging a bag of fluid at the bedside for continuous infusion over a certain period of time. These columns list the total amount of the fluid in the bag containing the solution.
STATUSDESCRIPTION states the ultimate status of the item, or more specifically, row. It is used to indicate why the delivery of the compound has ended. There are only six possible statuses:
- Changed - The current delivery has ended as some aspect of it has changed (most frequently, the rate has been changed)
- Paused - The current delivery has been paused
- FinishedRunning - The delivery of the item has finished (most frequently, the bag containing the compound is empty)
- Stopped - The delivery of the item been terminated by the caregiver
- Rewritten - Incorrect information was input, and so the information in this row was rewritten (these rows are primarily useful for auditing purposes - the rates/amounts described were not delivered and so should not be used if determining what compounds a patient has received)
- Flushed - A line was flushed.
Whether the order was from an open bag.
If the order ended on patient transfer, this field indicates if it continued into the next department (e.g. a floor).
If the order was canceled, this column provides some explanation.
COMMENTS_STATUS, COMMENTS_TITLE, COMMENTS_DATE
Specifies if the order was edited or canceled, and if so, the date and job title of the care giver who canceled or edited it.
Drugs are usually mixed within a solution and delivered continuously from the same bag. This column represents the amount of the drug contained in the bag at
STARTTIME. For the first infusion of a new bag,
TOTALAMOUNT. Later on, if the rate is changed, then the amount of the drug in the bag will be lower (as some has been administered to the patient). As a result,
ORIGINALAMOUNT will be the amount of drug leftover in the bag at that
This is the rate that was input by the care provider. Note that this may differ from
RATE because of various reasons:
ORIGINALRATE was the original planned rate, while the
RATE column will be the true rate delivered. For example, if a a bag is about to run out and the care giver decides to push the rest of the fluid, then
However, these two columns are usually the same, but have minor non-clinically significant differences due to rounding error.
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