The chartevents table

Table source: CareVue and Metavision ICU databases.

Table purpose: Contains all charted data for all patients.

Number of rows: 330,712,483

Links to:

• PATIENTS on SUBJECT_ID
• ADMISSIONS on HADM_ID
• ICUSTAYS on ICUSTAY_ID
• D_ITEMS on ITEMID
• CAREGIVERS on CGID

Brief summary

CHARTEVENTS contains all the charted data available for a patient. During their ICU stay, the primary repository of a patient’s information is their electronic chart. The electronic chart displays patients' routine vital signs and any additional information relevant to their care: ventilator settings, laboratory values, code status, mental status, and so on. As a result, the bulk of information about a patient’s stay is contained in CHARTEVENTS. Furthermore, even though laboratory values are captured elsewhere (LABEVENTS), they are frequently repeated within CHARTEVENTS. This occurs because it is desirable to display the laboratory values on the patient’s electronic chart, and so the values are copied from the database storing laboratory values to the database storing the CHARTEVENTS.

Important considerations

• Some items are duplicated between the labevents and chartevents tables. In cases where there is disagreement between measurements, labevents should be taken as the ground truth.

Table columns

Name	Postgres data type	In CareVue	In Metavision
ROW_ID	INT	Y	Y
SUBJECT_ID	NUMBER(7,0)	Y	Y
HADM_ID	NUMBER(7,0)	Y	Y
ICUSTAY_ID	NUMBER(7,0)	Y	Y
ITEMID	NUMBER(7,0)	Y	Y
CHARTTIME	DATE	Y	Y
STORETIME	DATE	Y	Y
CGID	NUMBER(7,0)	Y	Y
VALUE	VARCHAR2(200 BYTE)	Y	Y
VALUENUM	NUMBER	Y	Y
VALUEUOM	VARCHAR2(20 BYTE)	Y	Y
WARNING	NUMBER(1,0)		Y
ERROR	NUMBER(1,0)		Y
RESULTSTATUS	VARCHAR2(20 BYTE)	Y
STOPPED	VARCHAR2(20 BYTE)	Y

Detailed Description

SUBJECT_ID, HADM_ID, ICUSTAY_ID

Identifiers which specify the patient: SUBJECT_ID is unique to a patient, HADM_ID is unique to a patient hospital stay and ICUSTAY_ID is unique to a patient ICU stay.

ITEMID

Identifier for a single measurement type in the database. Each row associated with one ITEMID (e.g. 212) corresponds to an instantiation of the same measurement (e.g. heart rate).

CHARTTIME, STORETIME

CHARTTIME records the time at which an observation was made, and is usually the closest proxy to the time the data was actually measured. STORETIME records the time at which an observation was manually input or manually validated by a member of the clinical staff.

CGID

CGID is the identifier for the caregiver who validated the given measurement.

VALUE, VALUENUM

VALUE contains the value measured for the concept identified by the ITEMID. If this value is numeric, then VALUENUM contains the same data in a numeric format. If this data is not numeric, VALUENUM is null. In some cases (e.g. scores like Glasgow Coma Scale, Richmond Sedation Agitation Scale and Code Status), VALUENUM contains the score and VALUE contains the score and text describing the meaning of the score.

VALUEUOM

VALUEUOM is the unit of measurement for the VALUE, if appropriate.

WARNING, ERROR

WARNING and ERROR are Metavision specific columns which specify if a warning for the value was raised and if an error occurred during the measurement.

RESULTSTATUS, STOPPED

RESULTSTATUS and STOPPED are CareVue specific columns which specify the type of measurement (RESULTSTATUS is ‘Manual’ or ‘Automatic’) and whether the measurement was stopped.