The lab events table
Table source: Hospital database.
Table purpose: Contains all laboratory measurements for a given patient.
Number of rows: 606,057
Links to:
- PATIENTS on SUBJECT_ID
- ADMISSIONS on SUBJECT_ID
Summary
The LAB EVENTS data contains information regarding laboratory-based measurements. The process for acquiring a lab measurement is as follows: first, a member of the clinical staff collects a fluid sample from the patient’s body (e.g., blood from an arterial line, urine from a catheter). Next, the fluid is bar-coded to associate it with the patient and timestamped to record the time of acquisition. The laboratory analyses the sample and returns a result within 4–12 hours.
Table columns
| Name | Data type |
|---|---|
| ROW_ID | INT |
| SUBJECT_ID | INT |
| COLLECTION_DATE | DATETIME(0) |
| COLLECTION_TIME | TIMESTAMP(0) |
| VERIFICATION_DATE | DATETIME(0) |
| VERIFICATION_TIME | TIMESTAMP(0) |
| OBSERVATION | VARCHAR(200) |
| VALUENUM | DOUBLE PRECISION |
| VALUEUOM | VARCHAR(20) |
| NORMAL_RANGE | VARCHAR(20) |
Detailed description
SUBJECT_ID
Identifier which specifies the patient. SUBJECT_ID is unique to a patient.
COLLECTION_DATE, COLLECTION_TIME
COLLECTION_DATE and COLLECTION_TIME record the time at
which the sample or fluid was collected from the patient.
VERIFICATION_DATE, VERIFICATION_TIME
These fields indicate the time when the sample was tested and the result verified in the laboratory.
OBSERVATION, VALUENUM
OBSERVATION contains the value measured for the lab test performed.
If this value is numeric, VALUENUM contains the same data in numeric
format. If the data is not numeric, VALUENUM is null.
VALUEUOM, NORMAL_RANGE
VALUEUOM is the unit of measurement for the observation, if appropriate.
NORMAL_RANGE specifies the clinically accepted reference range for
the corresponding laboratory observation, providing the lower and upper limits
used to determine whether a measured value falls within the normal range.