MIMIC-IV: Flag and comments of NTproBNP in labevents

[JengEnWu]

Prerequisites

• [X] 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 am doing an analysis about NTproBNP (itemid=50963) and using the flag column (normal/abnormal) as my target. For this reason, I would like to know the specific cut-offs of the flag. Although the ref_range_lower and ref_range_upper are provided in the data, I still don't know where these cut-offs come from.

In the comments column it says: "Reference values vary with age, sex, and renal function. at 35% prevalence, NTproBNP values:. < 450 have 99% Neg pred value. >1000 have 78% Pos pred value. See online lab manual for more detailed information.".

However, I can not find the online lab manual in the online documentation. Does anyone know where can I find the information about the cut-offs?