kbertodatti
commented
1 year ago @swmuir from Jenna:
Here is the new equation.
eGFR = 142 min(standardized Scr/K, 1)α max(standardized Scr/K, 1)-1.200 0.9938Age 1.012 [if female]
Abbreviations / Units
eGFR (estimated glomerular filtration rate) = mL/min/ 1.73 m2
Scr (serum creatinine) = mg/dL
K = 0.7 (females) or 0.9 (males)
α = -0.241 (females) or -0.302 (males)
min = indicates the minimum of Scr/K or 1
max = indicates the maximum of Scr/K or 1
There is also an equation that uses cystatin C that has superior performance. But cystatin C is not widely used in clinical care as of yet, so that equation would be lower priority.
Agree with both patient and provider apps being the same.
From Dave: Following up on our very brief conversation about eGFR in yesterday's call. We have no documentation on what was done previously, or why. But Sean found some code in the provider app to calculate eGFR from its components, presumably as a replacement for using any lab results for eGFR. There is no allowance for this in the MyCarePlanner patient app.
I recall hearing something about this from RTI calls before EMI was involved. As you said yesterday, to use an updated race-agnostic formula. Is that correct?
Is this still necessary or are current lab results returned with the updated algorithm, and an updated LOINC code? Do we need to continue using this calculation, but only when old eGFR result LOINC codes are used?
Himali, I included you in this thread to ask for assistance to review current LOINC codes for eGFR in our IG value sets. Thanks!
From Jenna: If memory serves, we ultimately opted to recalculate eGFR in order to be able to graph it.
There were a few issues with the reported eGFRs:
EMAIL THREAD: Yes, recalculating is the ideal solution. This would ignore the existing eGFR value sets.
Both MDRD and CKD-EPI equations correct for race, sex and age.
One option that might be ideal actually would be to report 2 results for everyone, regardless of whether we know their race… Result is X with race correction and Y without race correction – given all the controversy around the race correction. Would that be too complicated?
From: Jerry Goodnough Date: Monday, August 23, 2021 at 12:15 PM To: Norton, Jenna (NIH/NIDDK) [E] Subject: Re: Egfr text values Ok next odd question - Looking at our eGFR value set I see coding for the value sets I see a number possible codings - Looking at the formula you sent I see if is CKD-EPI, which would imply is I have all the data (Gender and Ethnicity) I could just use this code and return a single result. The other codes seem to be based on MDRD and break down the coding by a few possible criteria (Extract of value set follows), but does not include a coding for Black Female. I am not sure of the difference between MDRD and the CKD-EPI calculations methods and the missing combination concerns me - My inclination would be to calculate and report the CKD-EPI based on the known ethnicity and gender. Which leaves open what to do about what to do when information is missing - In specific Date of Birth, Gender and Ethnicity. The issue being there is no clear code to report a variant set for Ethnicity (Unless MDRD with do and even the what would I report for black females?). One approach would be to say if any of these are unknown to just report the existing eGFR data from the server and only calculate when all data is known. My gut felling is that the one element that is likely to be missing would be Ethnicity, so we might make assumed value policy for it…. In any case we should have a policy for when any of these are unknown and what we want to display.
http://loinc.org,2.68,48642-3,Glomerular filtration rate/1.73 sq M.predicted among non-blacks [Volume Rate/Area] in Serum, Plasma or Blood by Creatinine-based formula (MDRD) http://loinc.org,2.68,48643-1,Glomerular filtration rate/1.73 sq M.predicted among blacks [Volume Rate/Area] in Serum, Plasma or Blood by Creatinine-based formula (MDRD) http://loinc.org,2.68,50044-7,Glomerular filtration rate/1.73 sq M.predicted among females [Volume Rate/Area] in Serum, Plasma or Blood by Creatinine-based formula (MDRD)
On Aug 23, 2021, at 8:33 AM, Norton, Jenna
Jerry – thanks, yes.
I think the apps and data standards we’ve developed as a whole are currently focused on adult care.
Pediatrics is a place we will need to think more about in the future.
From: Jerry Goodnough Date: Monday, August 23, 2021 at 11:26 AM To: Norton, Jenna (NIH/NIDDK) [E] Subject: Re: Egfr text values Jenna,
I was reading the fine print on eGFR and saw the following note: "This equation should only be used for patients 18 and older.” - Should I suppress the generation of results for patients under age 18?
Jerry
On Aug 11, 2021, at 1:48 PM, Norton, Jenna
GFR = 141 × min (Scr /κ, 1)α × max(Scr /κ, 1)-1.209 × 0.993Age × 1.018 [if female] × 1.159 [if black] where: Scr is serum creatinine in mg/dL, κ is 0.7 for females and 0.9 for males, α is -0.329 for females and -0.411 for males, min indicates the minimum of Scr /κ or 1, and max indicates the maximum of Scr /κ or 1.