Package {egfr}

egfr: Estimated Glomerular Filtration Rate Calculators

Description

A vectorised toolkit implementing 20 validated equations for estimating glomerular filtration rate (eGFR) and creatinine clearance from serum creatinine, cystatin C, or both, plus helpers for body surface area, KDIGO CKD staging, and unit conversion.

Details

All ⁠egfr_*()⁠ functions are fully vectorised: every numeric argument may be a scalar or a vector. Scalars are recycled against the longest vector. Results are returned unrounded (full precision) in mL/min/1.73m^2, except egfr_cockcroft_gault() which returns creatinine clearance in mL/min.

Author(s)

Maintainer: Markus Hovd markus@hovd.io [copyright holder]

Authors:

• Markus Hovd markus@hovd.io [copyright holder]

See Also

Useful links:

• https://github.com/mhovd/egfr

• https://mhovd.github.io/egfr/

• Report bugs at https://github.com/mhovd/egfr/issues

Body surface area (BSA)

Description

Computes body surface area, used to convert between absolute (mL/min) and BSA-normalised (mL/min/1.73m^2) GFR.

Usage

bsa(weight, height, method = c("dubois", "haycock", "mosteller"))

Arguments

Value

Numeric vector of body surface area in m^2.

References

Du Bois D, Du Bois EF. Arch Intern Med. 1916;17:863-871. Haycock GB, et al. J Pediatr. 1978;93(1):62-66. Mosteller RD. N Engl J Med. 1987;317(17):1098.

Examples

bsa(weight = 80, height = 180)
bsa(weight = 20, height = 110, method = "haycock")

KDIGO CKD stage from eGFR

Description

Classifies eGFR values into KDIGO GFR categories (G1-G5).

Usage

ckd_stage(egfr)

Arguments

Value

Character vector of GFR categories: "G1", "G2", "G3a", "G3b", "G4", or "G5".

References

Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline. Kidney Int Suppl. 2013.

Examples

ckd_stage(c(95, 72, 50, 35, 20, 8))

Convert serum creatinine between mg/dL and umol/L

Description

Convert serum creatinine between mg/dL and umol/L

Usage

convert_creatinine(creatinine, from = "mg/dl", to = "umol/l")

Arguments

Value

Numeric vector of converted creatinine.

Examples

convert_creatinine(88.4, from = "umol/l", to = "mg/dl")
convert_creatinine(1.0, from = "mg/dl", to = "umol/l")

Berlin Initiative Study (BIS1) creatinine eGFR (2012)

Description

Estimates GFR from serum creatinine using the BIS1 equation (Schaeffner et al., 2012), developed in an elderly (>= 70 years) German cohort.

Usage

egfr_bis_cr(
  creatinine,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Schaeffner ES, Ebert N, Delanaye P, et al. Two novel equations to estimate kidney function in persons aged 70 years or older. Ann Intern Med. 2012;157(7):471-481. doi:10.7326/0003-4819-157-7-201210020-00003

Examples

egfr_bis_cr(creatinine = 1.1, age = 75, sex = "female")

CAPA paediatric cystatin C eGFR (2014)

Description

Estimates GFR from serum cystatin C using the Caucasian, Asian, paediatric, and adult (CAPA) equation (Grubb et al., 2014).

Usage

egfr_capa(cystatin, age)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Grubb A, Horio M, Hansson LO, et al. Generation of a new cystatin C-based estimating equation for GFR by use of 7 assays standardized to the international calibrator. Clin Chem. 2014;60(7):974-986. doi:10.1373/clinchem.2013.220707

Examples

egfr_capa(cystatin = 1.0, age = 12)

CKD-EPI 2009 creatinine eGFR (with race coefficient)

Description

Estimates GFR from serum creatinine using the original CKD-EPI 2009 creatinine equation (Levey et al., 2009), which includes a race coefficient. Retained for historical comparison; the race-free egfr_ckdepi_cr_2021() is now recommended.

Usage

egfr_ckdepi_cr_2009(
  creatinine,
  age,
  sex,
  ethnicity = NULL,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female",
  label_afroamerican = c("black", "Black")
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604-612. doi:10.7326/0003-4819-150-9-200905050-00006

Examples

egfr_ckdepi_cr_2009(creatinine = 1.0, age = 50, sex = "female")
egfr_ckdepi_cr_2009(1.0, 50, "female",
  ethnicity = "black", label_afroamerican = "black"
)

CKD-EPI 2021 creatinine eGFR (race-free)

Description

Estimates GFR from serum creatinine using the race-free CKD-EPI 2021 creatinine equation (Inker et al., 2021). This is the equation recommended for adults (>= 18 years) by current US guidelines.

Usage

egfr_ckdepi_cr_2021(
  creatinine,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Inker LA, Eneanya ND, Coresh J, et al. New creatinine- and cystatin C-based equations to estimate GFR without race. N Engl J Med. 2021;385(19):1737-1749. doi:10.1056/NEJMoa2102953

Examples

egfr_ckdepi_cr_2021(creatinine = 1.0, age = 50, sex = "female")
egfr_ckdepi_cr_2021(c(0.8, 1.2), c(40, 65), c("female", "male"))

CKD-EPI 2021 combined creatinine + cystatin C eGFR (race-free)

Description

Estimates GFR using both serum creatinine and cystatin C with the race-free CKD-EPI 2021 combined equation (Inker et al., 2021). This is the most accurate of the CKD-EPI equations when both biomarkers are available.

Usage

egfr_ckdepi_cr_cys_2021(
  creatinine,
  cystatin,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Inker LA, Eneanya ND, Coresh J, et al. N Engl J Med. 2021;385(19):1737-1749. doi:10.1056/NEJMoa2102953

Examples

egfr_ckdepi_cr_cys_2021(
  creatinine = 1.0, cystatin = 0.9,
  age = 50, sex = "female"
)

CKD-EPI 2012 cystatin C eGFR

Description

Estimates GFR from serum cystatin C using the CKD-EPI 2012 cystatin C equation (Inker et al., 2012). The formula is identical to the race-free 2021 cystatin C equation and is retained for backward compatibility.

Usage

egfr_ckdepi_cys_2012(
  cystatin,
  age,
  sex,
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Inker LA, Schmid CH, Tighiouart H, et al. Estimating GFR from serum creatinine and cystatin C. N Engl J Med. 2012;367(1):20-29. doi:10.1056/NEJMoa1114248

Examples

egfr_ckdepi_cys_2012(cystatin = 0.9, age = 55, sex = "male")

CKD-EPI 2021 cystatin C eGFR (race-free)

Description

Estimates GFR from serum cystatin C using the race-free CKD-EPI 2021 cystatin C equation (Inker et al., 2021). The identical formula was first published in 2012; see egfr_ckdepi_cys_2012().

Usage

egfr_ckdepi_cys_2021(
  cystatin,
  age,
  sex,
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Inker LA, Eneanya ND, Coresh J, et al. N Engl J Med. 2021;385(19):1737-1749. doi:10.1056/NEJMoa2102953

Examples

egfr_ckdepi_cys_2021(cystatin = 0.9, age = 55, sex = "male")

CKiD U25 creatinine eGFR

Description

Estimates GFR in children and young adults (ages 1-25) using the CKiD U25 creatinine equation (Pierce et al., 2021). This is the first-choice paediatric equation.

Usage

egfr_ckid_u25_cr(
  creatinine,
  age,
  sex,
  height,
  creatinine_units = "mg/dl",
  height_units = "cm",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pierce CB, Munoz A, Ng DK, Warady BA, Furth SL, Schwartz GJ. Age- and sex-dependent clinical equations to estimate GFR in children and young adults with CKD. Kidney Int. 2021;99(4):948-956. doi:10.1016/j.kint.2020.10.047

Examples

egfr_ckid_u25_cr(creatinine = 0.6, age = 10, sex = "male", height = 140)

CKiD U25 combined creatinine + cystatin C eGFR

Description

Arithmetic mean of the CKiD U25 creatinine (egfr_ckid_u25_cr()) and cystatin C (egfr_ckid_u25_cys()) estimates.

Usage

egfr_ckid_u25_cr_cys(
  creatinine,
  cystatin,
  age,
  sex,
  height,
  creatinine_units = "mg/dl",
  height_units = "cm",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pierce CB, et al. Kidney Int. 2021;99(4):948-956. doi:10.1016/j.kint.2020.10.047

Examples

egfr_ckid_u25_cr_cys(
  creatinine = 0.6, cystatin = 0.8, age = 10,
  sex = "male", height = 140
)

CKiD U25 extended creatinine eGFR (to age 30)

Description

Research extension of egfr_ckid_u25_cr() with kappa values that continue to age 30.

Usage

egfr_ckid_u25_cr_extended(
  creatinine,
  age,
  sex,
  height,
  creatinine_units = "mg/dl",
  height_units = "cm",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pierce CB, et al. Kidney Int. 2021;99(4):948-956. doi:10.1016/j.kint.2020.10.047

Examples

egfr_ckid_u25_cr_extended(
  creatinine = 1.0, age = 28, sex = "female",
  height = 165
)

CKiD U25 cystatin C eGFR

Description

Estimates GFR in children and young adults (ages 1-25) using the CKiD U25 cystatin C equation (Pierce et al., 2021).

Usage

egfr_ckid_u25_cys(
  cystatin,
  age,
  sex,
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pierce CB, et al. Kidney Int. 2021;99(4):948-956. doi:10.1016/j.kint.2020.10.047

Examples

egfr_ckid_u25_cys(cystatin = 0.8, age = 10, sex = "male")

Cockcroft-Gault creatinine clearance

Description

Estimates creatinine clearance (not BSA-normalised eGFR) using the Cockcroft-Gault equation (Cockcroft & Gault, 1976). Commonly used for drug dosing.

Usage

egfr_cockcroft_gault(
  creatinine,
  age,
  sex,
  weight,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of creatinine clearance in mL/min.

References

Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31-41. doi:10.1159/000180580

Examples

egfr_cockcroft_gault(creatinine = 1.0, age = 50, sex = "male", weight = 80)

EKFC creatinine eGFR (2021)

Description

Estimates GFR from serum creatinine using the European Kidney Function Consortium (EKFC) creatinine equation (Pottel et al., 2021). Valid across the full age spectrum (2-120 years).

Usage

egfr_ekfc_cr(
  creatinine,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female",
  q = NULL
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pottel H, Bjork J, Courbebaisse M, et al. Development and validation of a modified full age spectrum creatinine-based equation to estimate glomerular filtration rate. Ann Intern Med. 2021;174(2):183-191. doi:10.7326/M20-4366

Examples

egfr_ekfc_cr(creatinine = 1.0, age = 50, sex = "female")
egfr_ekfc_cr(0.5, 8, "male")
egfr_ekfc_cr(1.0, 50, "female", q = 0.72)

EKFC combined creatinine + cystatin C eGFR (2023)

Description

Arithmetic mean of the EKFC creatinine (egfr_ekfc_cr()) and EKFC cystatin C (egfr_ekfc_cys()) estimates.

Usage

egfr_ekfc_cr_cys(
  creatinine,
  cystatin,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female",
  q_cr = NULL,
  q_cys = NULL
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pottel H, Bjork J, Rule AD, et al. N Engl J Med. 2023;388(4):333-343. doi:10.1056/NEJMoa2203769

Examples

egfr_ekfc_cr_cys(creatinine = 1.0, cystatin = 0.9, age = 50, sex = "female")

EKFC cystatin C eGFR (2023)

Description

Estimates GFR from serum cystatin C using the sex- and race-free EKFC cystatin C equation (Pottel et al., 2023).

Usage

egfr_ekfc_cys(cystatin, age, q = NULL)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pottel H, Bjork J, Rule AD, et al. Cystatin C-based equation to estimate GFR without the inclusion of race and sex. N Engl J Med. 2023;388(4):333-343. doi:10.1056/NEJMoa2203769

Examples

egfr_ekfc_cys(cystatin = 0.9, age = 50)
egfr_ekfc_cys(0.9, 50, q = 0.85)

Full Age Spectrum (FAS) creatinine eGFR

Description

Estimates GFR from serum creatinine using the Full Age Spectrum equation (Pottel et al., 2016). Uses adult reference Q values (male 0.90, female 0.70 mg/dL) across all ages.

Usage

egfr_fas_cr(
  creatinine,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Pottel H, Hoste L, Dubourg L, et al. An estimated glomerular filtration rate equation for the full age spectrum. Nephrol Dial Transplant. 2016;31(5):798-806. doi:10.1093/ndt/gfv454

Examples

egfr_fas_cr(creatinine = 1.0, age = 50, sex = "female")

Lund-Malmoe Revised creatinine eGFR (2011)

Description

Estimates GFR from serum creatinine using the revised Lund-Malmoe equation (Bjork et al., 2011). Piecewise-linear in plasma creatinine (umol/L) with sex-specific knots.

Usage

egfr_lund_malmo(
  creatinine,
  age,
  sex,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Bjork J, Grubb A, Sterner G, Nyman U. Revised equations for estimating glomerular filtration rate based on the Lund-Malmo Study cohort. Scand J Clin Lab Invest. 2011;71(3):232-239. doi:10.3109/00365513.2011.557086

Examples

egfr_lund_malmo(creatinine = 1.0, age = 50, sex = "female")

MDRD 4-variable eGFR (IDMS-standardised)

Description

Estimates GFR from serum creatinine using the IDMS-traceable 4-variable MDRD Study equation (Levey et al., 2006). Historical; superseded by CKD-EPI for clinical use.

Usage

egfr_mdrd(
  creatinine,
  age,
  sex,
  ethnicity = NULL,
  creatinine_units = "mg/dl",
  label_sex_male = "male",
  label_sex_female = "female",
  label_afroamerican = c("black", "Black")
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Levey AS, Coresh J, Greene T, et al. Using standardized serum creatinine values in the MDRD study equation. Ann Intern Med. 2006;145(4):247-254. doi:10.7326/0003-4819-145-4-200608150-00004

Examples

egfr_mdrd(creatinine = 1.2, age = 60, sex = "male")

Neonatal creatinine eGFR (2022)

Description

Estimates GFR in term-born neonates using the equation of Smeets et al. (2022). Requires IDMS-standardised creatinine.

Usage

egfr_neonatal(
  creatinine,
  height,
  creatinine_units = "mg/dl",
  height_units = "cm"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Smeets NJL, IntHout J, van der Burgh MJP, et al. SCr- and cystatin C-based equations to estimate GFR in term-born neonates. J Am Soc Nephrol. 2022;33(7):1277-1292. doi:10.1681/ASN.2021111453

Examples

egfr_neonatal(creatinine = 0.5, height = 50)

Schwartz bedside paediatric eGFR (2009)

Description

Estimates GFR in children using the bedside Schwartz equation (Schwartz et al., 2009). Requires IDMS-standardised creatinine.

Usage

egfr_schwartz(
  creatinine,
  height,
  creatinine_units = "mg/dl",
  height_units = "cm"
)

Arguments

Value

Numeric vector of eGFR in mL/min/1.73m^2.

References

Schwartz GJ, Munoz A, Schneider MF, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20(3):629-637. doi:10.1681/ASN.2008030287

Examples

egfr_schwartz(creatinine = 0.5, height = 120)

Normalise or de-normalise GFR using body surface area

Description

Converts between absolute creatinine clearance (mL/min) and BSA-normalised GFR (mL/min/1.73m^2).

Usage

gfr_bsa_adjust(gfr, bsa, to = c("normalized", "absolute"))

Arguments

Value

Numeric vector of converted GFR.

Examples

gfr_bsa_adjust(100, bsa = 2.0, to = "normalized")
gfr_bsa_adjust(90, bsa = 2.0, to = "absolute")