MIMIC-IV Change log

Changes between releases of MIMIC-IV.

The latest version of MIMIC-IV is v1.0.

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 (this issue number relates to a private ‘building’ repository).

MIMIC-IV v1.0

MIMIC-IV v1.0 was released March 16th, 2021.

core

  • admissions
    • A number (~1000, <1%) of erroneous hadm_id have been removed.
  • patients
    • 942 subject_id have been removed as they were only associated with the above erroneous hadm_id.
    • dod is now populated using the patient’s deathtime from their latest hospitalization (reported in #71, thanks @jinjinzhou).
    • At the moment, out-of-hospital mortality is not captured by dod
  • transfers
    • Removed erroneous transfers included in the previous version.
    • transfer_id has been regenerated. transfer_id in MIMIC-IV v1.0 are not compatible with transfer_id from v0.4. We do not intend to change transfer_id when updating MIMIC-IV, but had to update it due to an error in its generation.
    • All hadm_id in transfers are also present in admissions and vice-versa (reported in #84, thanks @kokoko12305).

icu

  • icustays
    • ICU stays were inappropriately assigned in the previous version due to an error in the preprocessing code. Previously, non-ICU ward transfers were included in the ICU stays, and certain ward stays were not treated as ICU stays (reported in #67, thanks @JHLiu7 and @stefanhgm). The assignment of stay_id has been regenerated.
    • The mapping between hospital transfers and ICU stays has been updated.
    • stay_id in MIMIC-IV v1.0 are not compatible with stay_id from v0.4. We do not intend to change stay_id when updating MIMIC-IV, but had to update it due to an error in its generation.
  • The change in icustays has re-assigned values to new stay_id, as a result all tables have had their content changed (due to a change in stay_id), but the structure is unchanged.

hosp

  • hcpcsevents
    • Data has been added for a number of previously excluded hospitalizations.
    • The table now has a chartdate column, containing the date associated with the code. Every row is associated with a date.
  • drgcodes
    • Data has been added for a number of previously excluded hospitalizations.
    • Duplicate DRG codes have been removed from the table.
    • Descriptions have been updated using the latest dictionaries made available from the Massachusetts government website and HCUP.
  • diagnoses_icd, d_icd_diagnoses
    • Data has been added for a number of previously excluded hospitalizations (reported in #27, thanks @yugangjia).
    • The icd_code column is now trimmed and stored as a VARCHAR, i.e. codes no longer contain trailing whitespaces (850 -> 850).
    • Missing ICD codes have been added to the dictionary. All ICD codes in the diagnoses_icd table have an associated reference in d_icd_diagnoses.
  • labevents
    • The comments field has been updated, fixing a bug where comments longer than 4096 characters were truncated. Due to the deidentification, it’s unlikely users will see much difference, as these comments will appear as ___.
  • procedures_icd
    • Data has been added to procedures_icd for a number of previously excluded hospitalizations.
    • The table now has a chartdate column, containing the date associated with each billed procedure.
    • The icd_code column is now trimmed and stored as a VARCHAR, i.e. codes no longer contain trailing whitespaces (850 -> 850).
    • Missing ICD codes have been added to the dictionary. All ICD codes in the procedures_icd table have an associated reference in d_icd_procedures.

MIMIC-IV v0.4

MIMIC-IV v0.4 was released August 13th, 2020.

  • d_micro
    • This table has been removed
  • microbiologyevents
    • Added the spec_type_desc, test_name, org_name, and ab_name columns
      • These columns contain the textual name of the organism/antibiotic/test/specimen
    • Added the comments column
      • this column contains information about the test, and in some cases (e.g. viral load tests), contains the result
    • micro_specimen_id has been regenerated; the values will not match previous versions.

MIMIC-IV v0.3

MIMIC-IV v0.3 was released July 13th, 2020.

  • Fixed an alignment issue in shifted dates/times

MIMIC-IV v0.2

MIMIC-IV v0.2 was released June 23rd, 2020.

  • Updated demographics in the patient table
    • anchor_year -> anchor_year_group
    • anchor_year_shifted -> anchor_year
    • See the patients table for detail on these columns
  • transfers
    • Deleted the los column
  • emar
    • mar_id -> emar_id
      • emar_id is now a composite of subject_id and emar_seq, and has form “subject_id-emar_seq”
    • emar_seq column - a monotonically increasing integer starting with the first eMAR administration
    • Added poe_id and pharmacy_id columns for linking to those tables
  • emar_detail
    • mar_id -> emar_id (changed as above)
    • Deleted the mar_detail_id column
  • hcpcsevents
    • ticket_id_seq -> seq_num
  • labevents
    • Many previously NULL values are now populated - these were removed originally due to deidentification
    • Added the comments column. This contains deidentified free-text comments with labs. PHI is replaced with three underscores (___). If an entire comment is ___, then the entire comment was scrubbed.
    • spec_id -> specimen_id
  • microbiologyevents
    • stay_id column removed
    • spec_id -> micro_specimen_id
  • Added the poe and poe_detail tables
    • Documentation of provider orders for various treatments and other aspects of patient management
  • Added the prescriptions table
    • Documentation of medicine prescriptions via the provider order interface
  • Added the pharmacy table
    • Detailed information regarding prescriptions provided by the pharmacy including formulary dose, route, frequency, dose, and so on.
  • inputevents
    • Fixed an error in the calculation of the amount column
  • icustays
    • Re-derived stay_id - the new stay_id are distinct from the previous version.
  • diagnosis
    • Added diagnosis table with similar schema as the diagnosis_icd table.
  • main
    • Removed diagnosis columns from this table (inserted into diagnosis above)

MIMIC-IV v0.1

MIMIC-IV v0.1 was released on 15 August 2019.