Calculate eGFR by Schwartz equation (for children only, both "classic" and "quadratic")

Usage

egfr.schwartz(
  creatinine,
  age,
  sex,
  height_cm = 0,
  height_ft = 0,
  height_inch = 0,
  creatinine_units = "micromol/l",
  equation_type = "classic",
  label_sex_male = c("Male", 1),
  label_sex_female = c("Female", 0)
)

Arguments

creatinine: Numeric vector. Serum creatinine, could be expressed in "micromol/L", "mmol/L" or "mg/dL". Units of measurement should be defined in variable creatinine_units (if not defined explicitly by user, the default value is "micromol/L").
age: Numeric vector. Age, in years. Age does not accounted in Schwartz equation, but used in the function to check whether Schwartz equation could be applied to a given patient.
sex: Vector. The value of variable refers to the parameters label_sex_male and label_sex_female. Required only in case of quadratic Schwartz equation.
height_cm: Numeric vector. Could be defined either as height_cm if is measured in cm, or as height_ft and height_inch if is measured in feet and inches. If the parameter height_cm is greater than 0, the function uses cm, otherwise - feet and inches.
height_ft: see height_cm
height_inch: see height_cm
creatinine_units: Character string. Units in which serum creatinne is expressed. Could be one of the following: "micromol/L", "mmol/L" or "mg/dL".
equation_type: Character string. Define whether to calculate eGFR either by classic Schwartz or quadratic Schwartz equation. Could be one of the following: "classic", "quadratic". If not explicitly defined by user, the default assumption is "classic".
label_sex_male: List. Label(s) for definition(s) of male sex.
label_sex_female: List. Label(s) for definition(s) of female sex.

Value

numeric eGFR expressed in ml/min/1.73m².

Details

Calculate estimated glomerular filtration rate (eGFR) by Schwartz equation.

Reference to the equation: Gao A, Cachat F, Faouzi M et al. Comparison of the glomerular filtration rate in children by the new revised Schwartz formula and a new generalized formula. Kidney International 2013;83:524–30.

Citation: Bikbov B. kidney.epi: Kidney-Related Functions for Clinical and Epidemiological Research. Scientific-Tools.Org, https://Scientific-Tools.Org. DOI: 10.32614/CRAN.package.kidney.epi

Author

Programming: Boris Bikbov https://www.linkedin.com/in/boris-bikbov.

Examples

# for a single patient
egfr.schwartz (creatinine = 1.4, age = 10, height_cm = 90, sex = "Male",
  creatinine_units = "mg/dl")
#> [1] 26.55
egfr.schwartz (creatinine = 1.4, age = 10, height_cm = 90, sex = "Male",
  creatinine_units = "mg/dl", equation_type = "quadratic")
#> [1] 23.68
# for a dataset - see vignettes for details
# egfr.schwartz (creatinine = dta$scr, age = dta$age, height_cm = dta$ht,
#  sex = dta$sex, creatinine_units = "mg/dl")