A vectorised function to calculate estimated glomerular filtration rate using the abbreviated (four variable) MDRD equation. By default the equation accepts serum creatinine in µmol/l but can be changed to mg/dl by setting the units parameter to "US". To allow for serial measurements over time, such as for transplant follow-up data, there is an optional offset = n parameter which increases the age value used in the equation by n years.

mdrd(creat, age, sex, ethnicity, units = "SI", offset = 0)

Arguments

creat

numeric vector of serum creatinine in µmol/l (or mg/dl if units = "US")

age

numeric vector of age in years (accepts integers or decimals)

sex

character vector of sex ("F" for female, "M" for male)

ethnicity

character vector of patient ethnicity, one of "black" or "non-black"

units

non-vectorised optional parameter for creatinine unit ("SI" for µmol/l (default), "US" for mg/dl)

offset

non-vectorised optional parameter for offset in years

Value

a numeric vector of eGFR values

Details

Reference: Levey AS, Greene T, Kusek JW, et al. A simplified equation to predict glomerular filtration rate from serum creatinine. J Am Soc Nephrol 2000; 11:A0828.

Examples

mdrd(creat = 120, age = 45.2, sex = "M", ethnicity = "non-black")
#> [1] 60.32037
mdrd(creat = 1.5, age = 64.3, sex = "F", ethnicity = "black", units = "US")
#> [1] 44.91859