Blood Gas Turnaround Time

[parthagarwal]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Checked the online documentation: https://mimic.mit.edu/
  • Checked that your issue isn't already addressed: https://github.com/MIT-LCP/mimic-code/issues?utf8=%E2%9C%93&q=

Description

I would like to calculate the turnaround time for blood gas measurements. Per the documentation, charttime is the time at which the measurement is recorded and storetime is the time at which the measurement is made available to the doctor and/or uploaded to the EMR. From this I am insinuating that the difference between the two can be considered to be the turnaround time - is this a valid assumption?

It is generally well-known that ABG measurements take 30-45 min. Even with automated ABG analyzers, it takes approximately 10-15min . It is surprising to see, then, that the dataset shows a much lower difference between storetime and charttime for ABG (75% within 4min). Could someone please help me understand what I am missing?

Query

SELECT *, date_diff(storetime,charttime,minute) as turnaround_time FROM physionet-data.mimiciv_hosp.labevents where itemid=50821

Histogram of 100k sample