All patients across all datasets are in the [hosp](/docs/iv/modules/hosp) module. However, not all ICU patients have ED data, not all ICU patients have CXRs, not all ED patients have hospital data, and so on. Within an individual dataset, there are also incomplete tables as certain electronic systems did not exist in the past, particularly the eMAR system.

The latest version of MIMIC-IV is v2.1.

This page lists changes implemented in sequential updates to the MIMIC-IV database. Issues are tracked using a unique issue number, usually of the form #100, #101, etc. Note that some of these issues are only accessible in a private 'building' repository.

MIMIC-IV v2.1 was released on November 14, 2022. It removed a subset of subject_id which will be retained internally as a test set. Future data releases will exclude these patients.

* A subset of patients were removed from the dataset. 15,748 subject_id were removed from the patients table. 23,093 hadm_id were removed from the admissions table. 3,762 stay_id were removed from the icustays table.

MIMIC-IV v2.0 was released on June 12, 2022. It focused on expanding the data elements available for patients within MIMIC-IV v1.0. Additional data available includes out-of-hospital date of death, information from the online medical record system (which includes height and weight), and more detail for continuous infusions in the ICU.

* The core module has been removed to simplify the schema. The _admissions_, _patients_, and _transfers_ tables are now in the hosp module.

* Neonates have been removed from the dataset. Neonatal data will be released in a separate project with data from the neonatal intensive care unit.

* _icustays_

* Around 700 stays (~1%) have changed due to the changes in the _patients_ table.

* _chartevents, d\_items_

* The problem list from MetaVision has been added. All problems are documented with the same `itemid` now present in _d\_items_: 220001. There are just over 1,000 unique problems. Most documented problems are related to the care plan for the patient and documented during nurse shift changes (either 7am or 7pm). Less frequently, the ongoing issues are documented here.

* _ingredientevents_

* This is a new table associated with _inputevents_. Each intravenous administration tracked in _inputevents_ is associated with a set of ingredients. These ingredients include water content, caloric information, and so on. The goal of the _inputevents_ table is to support nutrition research and to provide a mechanism for estimating fluid input via summing all instances of the water ingredient. These ingredients have been separated from the _inputevents_ table to simplify analysis and reduce the size of _inputevents_.

* _inputevents_

* Removed a single column which contained only null values: `cancelreason`.

* _procedureevents_

* Removed columns which contained only null values: `totalamount`, `totalamountuom`, `cancelreason`, `comments_editedby`, `comments_canceledby`, `comments_date`, `secondaryordercategoryname`.

* _admissions_

* Fixed an issue where hospitalizations were missing _edregtime_ and _edouttime_ when the patient was admitted via the ED (reported in [#1247](https://github.com/MIT-LCP/mimic-code/issues/1247), thanks [@MEladawi](https://github.com/MEladawi)).

* _patients_

* `dod` is now populated with out-of-hospital mortality from state death records. For patients admitted to the ICU, this change has increased capture of date of death from 8,223 records to 23,844 (i.e. we now have out-of-hospital mortality for an additional 15,621 ICU patients).

* The mechanism for determining patients included in MIMIC was changed. For the most part this has resulted in an improvement, particularly regarding the logic for merging patients who had distinct medical record numbers. As a result of this change, most tables have had a change in the data content. Approximately 1% of stays were affected.

* _transfers_

* Fixed a bug where the `outtime` for ED stays with no associated `hadm_id` (i.e. an ED stay where the individual was not admitted to the hospital) was incorrect. This resulted in all _transfers_ rows with a NULL `hadm_id` having an apparent stay of minutes or less. The `outtime` column has now been corrected.

* _labevents, d\_labitems_

* The `itemid` for _d\_labitems_ has been changed for 43 items. These are extremely infrequently documented and each `itemid` has fewer than 100 observations in _labevents_. The exact `itemid` are provided in the changelog file CHANGELOG.txt.

* Errors were found in the current values of `loinc_code` (reported in [#938](https://github.com/MIT-LCP/mimic-code/issues/938), thanks [@Mauvila](https://github.com/Mauvila)). In order to enable collaborative improvement, the `loinc_code` column has been removed, and will now be collaboratively developed in the [MIMIC Code Repository](https://github.com/MIT-LCP/mimic-code/). Initial values will be sourced from the hospital system.

* A number of labs which previously had the value in the comments field now have the value in the value field (reported in [#941](https://github.com/MIT-LCP/mimic-code/issues/941), thanks [@Mauvila](https://github.com/Mauvila)). This change makes the _labevents_ table more consistent with MIMIC-III, which had these values in the value field.

* _microbiologyevents_

* New organisms, tests, specimens, and antibiotics have been added.

* _omr_

* A new table has been added: _omr._ The source of this data is the Online Medical Record, and it contains miscellaneous information useful for understanding an individual's health. As of v2.0, the _omr_ table has the following information: blood pressure, height, weight, body mass index, and Estimated Glomerular Filtration Rate (eGFR). These values are available from both inpatient and outpatient visits, and in many cases a "baseline" value from before a patient's hospitalization is available.

* _prescriptions_

* The `formulary_drug_cd` table has been added back (was previously in MIMIC-III). This column has the same set of values as the `product_code` column of emar\_detail.

The `stay_id` present in *icustays* is derived from the `stay_id` values in the *transfers* table.

`dod` is the patient's date of death sourced from one of two sources: the hospital database or a state death database. See the [*patients*](/docs/iv/modules/hosp/patients) documentation for more detail.

title: "Modules"

Data within the modules are available on PhysioNet:

* hosp, icu: [MIMIC-IV](https://physionet.org/content/mimiciv/)

* ed: [MIMIC-IV-ED](https://physionet.org/content/mimic-iv-ed/)

* note: [MIMIC-IV-Note](https://physionet.org/content/mimic-iv-note/)

* cxr: [MIMIC-CXR](https://physionet.org/content/mimic-cxr/)

The sections below describe data within each module.

**Number of rows:** 899,050

`icd_title` | TEXT NOT NULL

**Number of rows:** 425,087

`subject_id` | INTEGER NOT NULL

`hadm_id` | INTEGER NOT NULL

`stay_id` | INTEGER NOT NULL

`intime` | TIMESTAMP(0) NOT NULL

`outtime` | TIMESTAMP(0) NOT NULL

`gender` | VARCHAR(1) NOT NULL

`race` | VARCHAR(60)

`arrival_transport` | VARCHAR(50) NOT NULL

`disposition` | VARCHAR(255)

The patient's administrative gender as documented in the hospital system.

The patient's self-reported race. Race is aggregated into higher level categories for very small groups.

As of MIMIC-IV-ED v2.1, there were 33 unique categories for race.

The method through which the individual arrived at the ED. A count of the possible entries is provided below.

arrival_transport | count

--- | ---

WALK IN | 251849

AMBULANCE | 155752

UNKNOWN | 15352

OTHER | 1266

HELICOPTER | 868

The method through which the individual left the ED. Of the non-null methods, the possibilities include:

disposition | count

--- | ---

HOME | 241632

ADMITTED | 158010

TRANSFER | 7025

LEFT WITHOUT BEING SEEN | 6155

OTHER | 4297

LEFT AGAINST MEDICAL ADVICE | 1881

ELOPED | 5710

EXPIRED | 377

**Number of rows:** 2,987,342

**Number of rows:** 1,586,053

**Table purpose:** Store information collected on triage to the emergency department.

**Number of rows:** 425,087

There is no time associated with triage observations. The closest approximation to triage time is the `intime` of the patient from the *edstays* table.

The numeric entries in this table were originally stored as free-text. As a result, the columns required deidentification. Free-text entries which could not be converted trivially were removed. Normally, the application of deidentification in MIMIC-IV is indicated using three underscores (`___`) to make it clear to users that we have modified the data. However, due to the data type restriction, we were unable to do this in this case. As a result, **missing data in the numeric columns indicates either deidentified data or no data recorded**. However, this is usually rare. Below is a table demonstrating how often data were removed for deidentification purposes:

Column | Number of NULL values inserted for deidentification | Number of rows missing data in v2.1

--- | --- | ---

`temperature` | 680 | 23415

`heartrate` | 292 | 17090

`resprate` | 223 | 20353

`o2sat` | 414 | 20596

`sbp` | 238 | 18291

`dbp` | 214 | 19091

`acuity` | 0 | 6987

From the above, we can see that of the 23415 rows missing a `temperature` value, only 680 had a free-text value which was deleted during deidentification (~3%).

`pain` | TEXT

`chiefcomplaint` | VARCHAR(255)