Table of contents

Multimodal Clinical Monitoring in the Emergency Department (MC-MED)
Data Dictionary v1

Multimodal Clinical Monitoring in the Emergency Department (MC-MED)

Emergency department (ED) patients often present with undiagnosed complaints, and can exhibit rapidly evolving physiology. Therefore, data from continuous physiologic monitoring, in addition to the electronic health record, is essential to understand the acute course of illness and responses to interventions. The complexity of ED care and the large amount of unstructured multimodal data it produces has limited the accessibility of detailed ED data for research. We release Multimodal Clinical Monitoring in the Emergency Department (MC-MED), a comprehensive, multimodal, and de-identified clinical and physiological dataset. MC-MED includes 118,385 adult ED visits to an academic medical center from 2020 to 2022. Data include continuously monitored vital signs, physiologic waveforms (electrocardiogram, photoplethysmogram, respiration), patient demographics, medical histories, orders, medication administrations, laboratory and imaging results, and visit outcomes. MC-MED is the first dataset to combine detailed physiologic monitoring with clinical events and outcomes for a large, diverse ED population.

Dataset Summary

		All	with Waveforms
Visits		118,385	83,623
Unique Patients		70,545	53,123
Age	Mean	53	55
Age	St. Dev.	20	20
Sex	Female	64,272 (54.29%)	45,500 (54.41%)
	Male	54,077 (45.68%)	38,098 (45.56%)
	Unknown	36 (0.03%)	25 (0.03%)
Race	White	47,504 (40.25%)	34,320 (41.18%)
	Other	39,951 (33.85%)	27,409 (32.89%)
	Asian	19,430 (16.46%)	13,927 (16.71%)
	Black or African American	7,653 (6.49%)	5,261 (6.31%)
	Native Hawaiian or Other Pacific Islander	2,468 (2.09%)	1,734 (2.08%)
	Declines to State	551 (0.47%)	365 (0.44%)
	American Indian or Alaska Native	309 (0.26%)	231 (0.28%)
	Unknown	143 (0.12%)	95 (0.11%)
Ethnicity	Non-Hispanic/Non-Latino	84,557 (71.65%)	60,313 (72.37%)
	Hispanic/Latino	32,494 (27.54%)	22,363 (26.83%)
	Declines to State	633 (0.54%)	436 (0.52%)
	Unknown	325 (0.28%)	230 (0.28%)
Triage Acuity	1-Resuscitation	1,066 (0.90%)	876 (1.05%)
	2-Emergent	27,880 (23.66%)	22,185 (26.64%)
	3-Urgent	77,259 (65.55%)	56,552 (67.91%)
	4-Semi-Urgent	10,973 (9.31%)	3,508 (4.21%)
	5-Non-Urgent	680 (0.58%)	150 (0.18%)
ED Disposition	Discharge	70,246 (59.34%)	45,139 (53.98%)
	Inpatient	29,483 (24.90%)	23,583 (28.20%)
	Observation	15,890 (13.42%)	12,631 (15.10%)
	ICU	2,766 (2.34%)	2,270 (2.71%)
Chief Complaint (Top 7)	Abdominal Pain	10,568 (8.93%)	8,079 (9.66%)
	Chest Pain	6,239 (5.27%)	5,197 (6.22%)
	Fall	5,204 (4.40%)	3,854 (4.61%)
	Shortness Of Breath	4,507 (3.81%)	3,818 (4.57%)
	Back Pain	2,464 (2.08%)	1,510 (1.81%)
	Headache	2,173 (1.84%)	1,560 (1.87%)
	Fever	2,089 (1.77%)	1,648 (1.97%)

Data Dictionary `v1`

File Tree

./
└── mcmed-stanford-multi/
    └── v1/
        ├── labs.csv
        ├── meds.csv
        ├── numerics.csv
        ├── orders.csv
        ├── pmh.csv
        ├── rads.csv
        ├── split_*.csv
        ├── visits.csv
        ├── waveform_summary.csv
        └── waveforms/
            ├── 000/ (Last three digits of visit id)
            │   ├── 99013000/ (CSN - visit id)
            │   │   ├── II/
            │   │   │   ├── 99180000_1.dat
            │   │   │   └── 99180000_1.hea
            │   │   ├── Pleth/
            │   │   │   ├── 99180000_1.dat
            │   │   │   ├── 99180000_1.hea
            │   │   │   ├── 99180000_2.dat
            │   │   │   └── 99180000_2.hea
            │   │   └── Resp/
            │   │       ├── 99180000_1.dat
            │   │       └── 99180000_1.hea
            │   ...
            ├── 000/
            ...

Physiological Waveforms

This dataset contains three types of physiological waveforms as described in Table 2. The waveform segments are stored as WaveForm DataBase (WFDB) files, which are nested in the waveforms directory. The waveform segments will be found following this pattern:
./waveforms/{CSN[-3:]}/{CSN}/{type}/{CSN}_{segment_number}

Waveform Type Description

Type	Description	Common Uses
Electrocardiogram (ECG)	Records the voltage and timing of the heart’s electrical activity	Diagnosis of myocardial injury, arrhythmias, electrolyte derangements; assessment of medication responses
Photoplethysmogram (Pleth/PPG)	Records changes in blood volume over time at the site of the sensor	Estimation of heart rate, respiratory rate, blood pressure, blood oxygen saturation
Respiration (Resp)	Estimates chest wall expansion and contraction	Estimation of respiratory rate, tidal volume, respiratory function

Waveform Reference

waveform_summary.csv – This table is a reference for the waveform data. The number of segments are a result of removing sections of the signal record that did not show changes in signal readings. During a patient’s visit, the patient may be disconnected from the diagnostic instruments for various reasons. These gaps were removed, and the remaining segments with varying signal were stored as separate files.

Rows: 188,315
Columns: 4

Waveform Summary Data Elements

Column Name	Description	Data Type	Sample Data
CSN	Visit identifier (Random ID mapped to original CSN)	int	99633476
Type	One of 3 waveforms - `II` Electrocardiogram - `Pleth` Photoplethysmogram - `Resp` Respiration	string	Pleth
Segments	The number of waveform segments	int	1
Duration	The total duration for all segments for the waveform type, in seconds	float	119.984

Tabular Data Descriptions

Emergency Department Visits

visits.csv – This table describes high-level characteristics of each visit.

Rows: 118,385
Columns: 33

Visits Data Elements

Column Name	Description	Data Type	Sample Data
MRN	Patient identifier (Random ID mapped to original MRN)	int	99940664
CSN	Visit identifier (Random ID mapped to original CSN)	int	98874959
Visit_no	The visit number for this patient in the dataset	int	1
Visits	Total number of visits for this patient in the dataset	int	1
Age	Patient age in years at time of visit (Random perturbation of age +/- 2 years, Ages greater than 90 set to 90)	int	90
Gender	Patient gender	string	F
Race	Patient race	string	White
Ethnicity	Patient hispanic ethnicity	string	Non-Hispanic/Non-Latino
Means_of_arrival	Means of arrival to the ED	string	Self
Triage_Temp	Temperature at triage (C)	float	36.7
Triage_HR	Heart rate at triage (bpm)	float	80.0
Triage_RR	Respiratory rate at triage (breaths per min.)	float	18.0
Triage_SpO2	Oxygen saturation at triage (%)	float	100.0
Triage_SBP	Systolic blood pressure at triage (mmHg)	float	128.0
Triage_DBP	Diastolic blood pressure at triage (mmHg)	float	78.0
Triage_acuity	Emergency Severity Index (ESI) at triage (1-5)	string	3-Urgent
CC	Chief complaint(s) at triage	string	ABDOMINAL PAIN
ED_dispo	Disposition of patient from the ED	string	Discharge
Hours_to_next_visit	For patients with a subsequent visit, number of hours from departure of current visit to arrival of next visit	float	40.0
Dispo_class_next_visit	Dispo_class for next visit	string	Discharge
ED_LOS	Length of ED stay, hours	float	4.82
Hosp_LOS	Length of hospital stay (including post-ED admission), days	float	1.0
DC_dispo	Final disposition of patient from the hospital	string	Home/Work (includes foster care)
Payor_class	Class of primary visit payor	string	Medicare
Admit_service	For admitted patients, service admitting the patient from the ED	string	Emergency Medicine
Dx_ICD9	Primary visit diagnosis, ICD9 code	string	786.50
Dx_ICD10	Primary visit diagnosis, ICD10 code	string	R07.9
Dx_name	Name of ICD10 code	string	Chest pain, unspecified type
Arrival_time	Time of arrival to ED (Random-shift date, keeping season constant)	datetime	2262-01-09T03:16:07Z
Roomed_time	Time of patient rooming (Random-shift date, keeping season constant)	datetime	2283-03-02T07:36:59Z
Dispo_time	Time of disposition decision (Random-shift date, keeping season constant)	datetime	2247-09-22T10:54:42Z
Admit_time	For admitted patients, time of admission order (Random-shift date, keeping season constant)	datetime	2283-03-02T12:29:59Z
Departure_time	Time of departure from ED (Random-shift date, keeping season constant)	datetime	2209-08-12T11:31:38Z

Orders

orders.csv – This table contains all orders placed by the ED physicians during the visit.

Rows: 3,288,744
Columns: 7

Orders Data Elements

Column Name	Description	Data Type	Sample Data
CSN	Visit identifier (Random ID mapped to original CSN)	int	99139687
Order_time	Time of order (Random-shift date, keeping season constant)	datetime	2226-01-15T15:39:22Z
Order_type	Type of order (lab, imaging, medication, etc)	string	Lab
Procedure_name	Name of order	string	CBC WITH DIFFERENTIAL
Procedure_ID	Identifier for order (Mapped to CPT codes)	string	LABMETC
First_admin_time	For medications, time of first administration (Random-shift date, keeping season constant)	datetime	2212-11-03T16:51:00Z
Result_time	For lab and imaging tests, time of result (Random-shift date, keeping season constant)	datetime	2295-08-25T16:55:28Z

Medications

meds.csv – This table contains patient home medications.

Rows: 235,718
Columns: 11

Meds Data Elements

Column Name	Description	Data Type	Sample Data
MRN	Patient identifier (Random ID mapped to original MRN)	int	99721983
Med_ID	Medication identifier (mapped to NDC id)	int	14113
NDC	National Drug Code identifier	string	69618-066-10
Name	Medication name	string	ASPIRIN 81 MG PO TBEC
Generic_name	Generic name	string	aspirin 81 mg tablet,delayed release
Med_class	High-level classification of the medication	string	VITAMIN D PREPARATIONS
Med_subclass	A more detailed classification	string	Vitamins - D Derivatives
Active	Indicates whether a patient was thought to be using the medication at the time of the visit	string	Y
Entry_date	Medication entry date (Random-shift date, keeping season constant)	date	2270-07-20T00:00:00Z
Start_date	Medication start date (Random-shift date, keeping season constant)	date	2275-08-31T00:00:00Z
End_date	Medication end date (Random-shift date, keeping season constant)	date	2241-08-06T00:00:00Z

Past Medical History

pmh.csv – This table contains prior diagnoses.

Rows: 755,341
Columns: 7

Pmh Data Elements

Column Name	Description	Data Type	Sample Data
MRN	Patient identifier (Random ID mapped to original MRN)	int	99084665
Noted_date	Date when the diagnosis was recorded (Random-shift date, keeping season constant)	date	2219-08-10T00:00:00Z
CodeType	Whether code is ICD9 or ICD10	string	Dx10
Code	Diagnosis code	string	I10
Desc10	Text description of the code	string	Essential (primary) hypertension
CCS	Clinical Classification Software category of the diagnosis	float	259.0
DescCCS	Text description of the CCS category	string	Residual codes; unclassified

Lab Test Results

labs.csv – This table gives the results for lab tests ordered during the ED visit.

Rows: 5,706,470
Columns: 12

Labs Data Elements

Column Name	Description	Data Type	Sample Data
CSN	Visit identifier (Random ID mapped to original CSN)	int	99880957
Order_time	Time of lab order (Random-shift date, keeping season constant)	datetime	2221-07-03T18:37:12Z
Result_time	Time of lab result (Random-shift date, keeping season constant)	datetime	2233-07-07T04:37:14Z
Display_name	Name of order	string	CBC with Differential (CBCD)
Abnormal	Flag for abnormal or critical result	string	Abnormal
Component_name	Name of lab component	string	SODIUM
Component_result	Lab result (Removed results containing dates or names)	string	Negative
Component_value	Lab value (Sometimes identical to result, sometimes different, e.g. result may be categorical and value numeric. Removed results containing dates or names)	string	1
Component_units	Units of component_value, where applicable	string	%
Component_abnormal	Flag for abnormal component_value	string	Normal
Component_nml_low	Low end of normal range for component	float	0.0
Component_nml_high	High end of normal range for component	float	5.2

Radiology

rads.csv – This table contains the results of imaging studies ordered during each ED visit.

Rows: 156,866
Columns: 5

Rads Data Elements

Column Name	Description	Data Type	Sample Data
CSN	Visit identifier (Random ID mapped to original CSN)	int	99002166
Order_time	Time of imaging order (Random-shift date, keeping season constant)	datetime	2205-07-07T11:11:36Z
Result_time	Time of imaging result (Random-shift date, keeping season constant)	datetime	2291-10-02T05:06:13Z
Study	Imaging study name	string	XR CHEST 1 VIEW
Impression	Imaging result impression (Used the Stanford AIMI De-identification tool JAMIA, HuggingFace)	string	“1. No acute cardiopulmonary disease.”

Numeric Monitoring Data

numerics.csv – This table contains the non-waveform monitoring data measured during each ED visit.

Rows: 47,821,508
Columns: 5

Numerics Data Elements

Column Name	Description	Data Type	Sample Data
CSN	Visit identifier (Random ID mapped to original CSN)	int	99833461
Source	Indicates whether a value was recorded by nursing (Chart) or derived directly from the monitoring database (Monitor)	string	Monitor
Measure	One of 12 measurements - `HR` Heart rate, heartbeats per minute - `RR` Respiratory rate, breaths per minute - `SpO2` Oxygen saturation by pulse oximetry, % - `SBP` Systolic blood pressure, mmHg - `DBP` Diastolic blood pressure, mmHg - `MAP` Mean arterial pressure, mmHg - `Temp` Body temperature, degrees Fahrenheit - `Perf` Mean last-minute perfusion index derived from the PPG waveform - `Pain` Self-reported pain rating, 0 (no pain) to 10 (worst pain) - `LPM_O2` Flow rate of supplemental oxygen, liters per minute - `1min_HRV` or `5min_HRV` Heart rate variability over the last 1 minute or 5 minutes, calculated as the standard deviation of the beat-to-beat RR interval of the ECG waveform over this period.	string	SpO2
Value	Observation value	float	100.0
Time	Timestamp of the measurement. When underlying observations are made more frequently than once per minute, they are aggregated to the mean value over the 60 seconds preceding the timestamp.	string	2247-05-09T06:40:42Z

Numerics Measure Description

Type	Description
Heart Rate (HR)	Number of heartbeats per minute; measured using ECG or PPG waveform
Respiratory Rate (RR)	Number of breaths per minute; typically measured using RESP waveform
Oxygen Saturation by Pulse Oximetry (SpO2)	Percentage of oxygen-saturated hemoglobin in blood; measured using PPG waveform.
Systolic Blood Pressure (SBP)	Highest pressure in arteries during heart contraction, recorded by sphygmomanometry
Diastolic Blood Pressure (DBP)	Lowest pressure in arteries during heart relaxation, recorded by sphygmomanometry
Mean Arterial Pressure (MAP)	Average pressure in a patient’s arteries during one cardiac cycle
Temperature in Degrees Fahrenheit (Temp)	Body temperature measured in degrees Fahrenheit
Perfusion (Perf)	Ratio of pulsatile to nonpulsatile peripheral blood flow, estimated using PPG waveform
Pain rating on 0-10 scale (Pain)	Patient’s self-reported pain level on a scale from 0 (no pain) to 10 (worst pain)
Liters Per Minute of Supplemental Oxygen (LPM_O2)	Flow rate of supplemental oxygen administered to the patient, measured in liters per minute
Heart Rate Variability over last 1 minute (1min_HRV)	Variability in the time interval between heartbeats over the last minute; indicates autonomic nervous system function
Heart Rate Variability over last 5 minutes (5min_HRV)	Variability in the time interval between heartbeats over the last five minutes; indicates autonomic nervous system function

Train-Validation-Test Splits

MC-MED contains two training/validation/test splits for general use. For both splits, the training set contains 80% of visits, and validation and test sets each contain 10% of visits. The visits for each patient are restricted to a single split, in order to prevent data leakage between sets.

Random Patient-level Split split_random_*.csv – The files contain the visit IDs (CSN) for the visits in each split set.

Chronological Split split_chrono_*.csv – All visits in the validation set occur after the final visit in the training set, and all visits in the test set occur after the final visit in the validation set. To prevent patient data leakage between sets, each patient (MRN) is again restricted to only one of the training, validation, or test sets. This results in 13,007 visits being removed from these sets, and exact splits of 78%, 11%, and 11% for training, validating, and testing sets, respectively.