Is there any reference to the definition of baseline creatinine?

Hi, I have recently read the definition of baseline creatinine , which is expressed as follows:

-- This query extracts the serum creatinine baselines of adult patients on each hospital admission.
-- The baseline is determined by the following rules:
-- i. if the lowest creatinine value during this admission is normal (<1.1), then use the value
-- ii. if the patient is diagnosed with chronic kidney disease (CKD), then use the lowest creatinine value during the admission, although it may be rather large.
-- iii. Otherwise, we estimate the baseline using the Simplified MDRD Formula:
-- eGFR = 186 × Scr^(-1.154) × Age^(-0.203) × 0.742Female
-- Let eGFR = 75. Scr = [ 75 / 186 / Age^(-0.203) / (0.742Female) ] ^ (1/-1.154)

I wonder that is there any reference to this definition of baseline creatinine?
Thank you!

Start by reviewing the baseline-creatinine definition quoted in the issue and locating the query or documentation where it appears. Done means identifying a supporting reference or documenting that the definition's source is unknown; no file or test is named in the issue.