In MIMIC-III, where do negative cultures appear? Is this different between CareVue patients and Metavision patients?

Despite the documentation's assertion (here) that "If the specimen is null, then the culture had no growth reported.", there are very few cases where either the spec_itemid or org_itemid are empty in the microbiologyevents table(I think it's less than 2k out of 328k). Also, in a manual inspection, it looks like most rows have an antibiotic test done, so as to determine sensitivity of the culture.

PROCEDUREEVENTS_MV seems to have information on cultures for Metavision patients, but this whole table confuses me too.

Edit: Clarified that paragraph 2 refers to the microbiologyevents table.

2 Answers 2


Negative cultures were added to the microbiologyevents table in version 1.4 of MIMIC-III: http://mimic.physionet.org/about/releasenotes/

  • #188 - Negative microbiology cultures are now recorded in MICROBIOLOGYEVENTS - negative cultures can be identified by a NULL value for the organism name (ORG_NAME).

Negative cultures were not available in prior versions of MIMIC-III.

  • 1
    Good to know. Thanks! Any comment on the Procedureevents_mv table? It has a number of culture events listed for a variety of tissues (e.g., itemid 225401). Are these also limited to only those cultures which result in a positive result as well? What is the meaning of the procedureevents_mv table in general? Commented May 2, 2016 at 23:21
  • That table is sourced from the patient flowsheet. It's just a way of charting data with a start time and an end time. Usually they are procedures since those fit nicely into this framework. I don't think they are 100% compliant on it though, so if something isn't charted, it may still have occurred. Commented May 10, 2016 at 17:40

From what it appears, an entry in the microbiologyevents table means that the test was performed, and a NULL value indicates that no microbiological agent was detected, for that particular agent in that particular specimen at that particular date/time stamp.

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