PUBLIC LIBRARY / CALCULATOR

KFRE (Kidney Failure Risk Equation)

Estimates kidney failure risk in the eligible population using the four-variable equation. Select the calibration version explicitly; interface language does not determine the region.

Calculate with transparency

Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.

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Method · Limits of application

Tangri 2011/2016; 4-variable KFRE, explicit regional calibration

Adults with CKD G3–G5 and eGFR < 60. The user selects the version; country is not inferred from language. Does not model competing mortality risk. A prediction is not a recommendation for dialysis, referral or treatment.

Conditions of use

Check the conditions of application before calculating. The result presents the documented formula or criteria; it does not establish a diagnosis or prescription.

Scope of this implementation

Parameters in this edition

Age · years
Sex
Estimated GFR · mL/min/1.73 m²
Urine albumin-to-creatinine ratio (ACR) · mg/g
Calibration version
Stable CKD G3–G5 confirmed; no acute kidney injury and no ongoing dialysis?

Sources and documentation

Method version

Tangri 2011/2016; 4-variable KFRE, explicit regional calibration

Formula and criteria

LP = −0.2201(age/10−7.036) + 0.2467(male−0.5642) − 0.5567(eGFR/5−7.222) + 0.451(ln ACR−5.137). Risk = 100(1−S₀^exp(LP)). S₀ at 2/5 years: original 0.9750/0.9240; North America recalibration 0.9751/0.8996; outside North America recalibration 0.9832/0.9365 (2016 supplement, appendix 2).

Population and limitations

Synthetic cases checked (4)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Age: 60 years
Sex: Male
Estimated GFR: 30 mL/min/1.73 m²
Urine albumin-to-creatinine ratio (ACR): 300 mg/g
Calibration version: Original equation · Canadian cohorts
Stable CKD G3–G5 confirmed; no acute kidney injury and no ongoing dialysis?: Yes

{
  "idade": 60,
  "sexo": "M",
  "tfg": 30,
  "rac": 300,
  "regiao": "original",
  "contexto": "1"
}

Expected result

{
  "r2": 8.63274698025854,
  "r5": 24.562621555417532,
  "linear": 1.2714417560699467,
  "region": "original"
}

Actual result

{
  "r2": 8.632746980258554,
  "r5": 24.56262155541753,
  "linear": 1.271441756069947,
  "region": "original"
}

Case 2

reference-002

Inputs

Age: 60 years
Sex: Male
Estimated GFR: 30 mL/min/1.73 m²
Urine albumin-to-creatinine ratio (ACR): 300 mg/g
Calibration version: Recalibrated for North America · 2016
Stable CKD G3–G5 confirmed; no acute kidney injury and no ongoing dialysis?: Yes

{
  "idade": 60,
  "sexo": "M",
  "tfg": 30,
  "rac": 300,
  "regiao": "na",
  "contexto": "1"
}

Expected result

{
  "r2": 8.59932568795834,
  "r5": 31.428953114210184,
  "linear": 1.2714417560699467,
  "region": "na"
}

Actual result

{
  "r2": 8.599325687958359,
  "r5": 31.428953114210202,
  "linear": 1.271441756069947,
  "region": "na"
}

Case 3

reference-003

Inputs

Age: 60 years
Sex: Male
Estimated GFR: 30 mL/min/1.73 m²
Urine albumin-to-creatinine ratio (ACR): 300 mg/g
Calibration version: Recalibrated outside North America · 2016
Stable CKD G3–G5 confirmed; no acute kidney injury and no ongoing dialysis?: Yes

{
  "idade": 60,
  "sexo": "M",
  "tfg": 30,
  "rac": 300,
  "regiao": "other",
  "contexto": "1"
}

Expected result

{
  "r2": 5.862864180312008,
  "r5": 20.859820612408566,
  "region": "other"
}

Actual result

{
  "r2": 5.862864180312021,
  "r5": 20.859820612408562,
  "linear": 1.271441756069947,
  "region": "other"
}

Case 4

reference-004

Inputs

Age: 70 years
Sex: Female
Estimated GFR: 45 mL/min/1.73 m²
Urine albumin-to-creatinine ratio (ACR): 30 mg/g
Calibration version: Original equation · Canadian cohorts
Stable CKD G3–G5 confirmed; no acute kidney injury and no ongoing dialysis?: Yes

{
  "idade": 70,
  "sexo": "F",
  "tfg": 45,
  "rac": 30,
  "regiao": "original",
  "contexto": "1"
}

Expected result

{
  "r2": 0.3764814285393566,
  "r5": 1.17070151512103,
  "linear": -1.9039241208703679
}

Actual result

{
  "r2": 0.37648142853935473,
  "r5": 1.170701515121031,
  "linear": -1.9039241208703674,
  "region": "original"
}

Source for the active edition

Tangri et al. 2016 · equations and supplement, appendix 2

Additional reading and history

Identifier: kfre

Original clinical content: Brazilian Portuguese.

Code and reproducibility

This tool’s code on GitHub

Download code and tests

Sources, version and reproduction instructions

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.