estimate_gfr_mdrd: Estimate creatinine clearance and glomerular filtration rate...
In LS31/clinicalcalculations: Clinical calculations

Description Usage Arguments Value Caveats References See Also

The MDRD formula is: 175 \times (\frac{\text{creatinine}}{88.4})^{-1.154} \times (\text{age})^{-0.203} \times S \times A, where S is 1 for males and 0.742 for females and A is 1.212 for African-Americans and 1 for non-African-Americans. This is the so-called 4-variable version (as opposed to the 6-variable version).

1	estimate_gfr_mdrd(creatinine, age, is_female, is_african_american)

`creatinine`	Creatinine (\text{μmol} \text{l}^{-1}).
`age`	Age (years).
`is_female`	`TRUE` if patient is female, `FALSE` if patient is male.
`is_african_american`	`TRUE` if patient is African-American, `FALSE` if patient is not.

eGFR (\text{ml} \text{min}^{-1} 1.73 \text{m}^{-2}), or NA if any parameters are NA.

Note that this formula returns an eGFR for a standardised body surface area of 1.73 m^2. The MDRD formula may underestimate actual glomerular filtration rate in healthy patients. The original publication used 186 as a constant, but this was later revised to 175 provided the laboratory had calibrated its serum creatinine measurements to isotope dilution mass spectrometry (and therefore, 175 is used here). The factor 'African-American' was published as black/non-black - I do not know if this is an acceptable/usable generalisation for all people with a black skin tone (or for people of other non-Caucasian, non-African-American descent for that matter).

Levey, A. S. A More Accurate Method To Estimate Glomerular Filtration Rate from Serum Creatinine: A New Prediction Equation. Ann Intern Med 130, 461 (1999). and Levey, A. S. et al. Using Standardized Serum Creatinine Values in the Modification of Diet in Renal Disease Study Equation for Estimating Glomerular Filtration Rate. Ann Intern Med 145, 247 (2006).

units::set_units(), units::drop_units()

LS31/clinicalcalculations documentation built on Nov. 20, 2020, 6:59 a.m.