Kidney Failure Risk Equation (4-variable)
2- or 5-year risk of kidney failure (dialysis / transplant) in CKD G3–G5
- NICE NG203
Sources last checked: 2026-10-13
Kidney Failure Risk Equation (4-variable)
2- or 5-year risk of kidney failure (dialysis / transplant) in CKD G3–G5
Validated in CKD G3–G5 (eGFR < 60). Use the non-North American or UK calibration in Europe — the original North American equation overestimates risk outside North America.
Interpretation
| < 5 % | Below the NICE NG203 referral threshold (which applies to the 5-year risk). |
|---|---|
| 5 % or more | NICE NG203: a 5-year risk above 5 % is a criterion for referral to specialist (nephrology) assessment. |
What is the Kidney Failure Risk Equation (4-variable)?
The 4-variable Kidney Failure Risk Equation (KFRE) predicts the 2- and 5-year risk of kidney failure needing dialysis or transplantation from age, sex, eGFR and urine albumin-creatinine ratio. Tangri et al. derived it in Canadian nephrology cohorts (JAMA 2011) and recalibrated it for non-North American populations in a 31-cohort meta-analysis (JAMA 2016); NICE uses a UK recalibration.
When to use it
- Adults with CKD G3–G5 (eGFR < 60 mL/min/1.73 m²)
- Nephrology referral decisions (NICE NG203: 5-year risk > 5 %)
- Planning for dialysis access and transplant work-up as risk rises
When not to use it
- eGFR ≥ 60 or acute kidney injury
- Kidney transplant recipients or patients already on dialysis
How it is calculated
Risk = 1 − S₀^exp(−0.2201 × (age/10 − 7.036) + 0.2467 × (male − 0.5642) − 0.5567 × (eGFR/5 − 7.222) + 0.4510 × (ln ACR[mg/g] − 5.137)) S₀: non-North America 0.9832 (2 y) / 0.9365 (5 y); UK (NICE NG203) 0.9570 (5 y); North America 0.9750 (2 y) / 0.9240 (5 y) ACR mg/mmol × 8.84 = mg/g (NICE: ÷ 0.113)
Clinical pearls and limitations
- Validated in CKD G3–G5 (eGFR < 60). Use the non-North American or UK calibration in Europe — the original North American equation overestimates risk outside North America.
- In Europe use the non-North American or UK calibration; the original North American baseline overestimates risk here.
- ACR in mg/mmol is converted to mg/g (× 8.84) before taking the logarithm.
- Albuminuria drives risk strongly — a tenfold higher ACR roughly doubles to triples the hazard.
- The equation ignores competing risk of death, so in very old patients predicted risk may exceed observed kidney failure.
Frequently asked questions
What KFRE score should prompt referral?
NICE NG203 recommends specialist referral when the 5-year risk of needing renal replacement therapy is greater than 5 %.
Which KFRE calibration should I use in Europe?
The non-North American calibration from Tangri 2016, or the UK recalibration used by NICE; both give lower risks than the original North American equation.
Can I enter ACR in mg/mmol?
Yes — select mg/mmol; it is converted to mg/g as the equation requires.
Evidence and guidelines
- Primary source: Tangri N et al. A predictive model for progression of chronic kidney disease to kidney failure. JAMA 2011;305(15):1553-1559; non-North American calibration: Tangri N et al. Multinational assessment of accuracy of equations for predicting risk of kidney failure: a meta-analysis. JAMA 2016;315(2):164-174.
- NICE NG203 Chronic kidney disease: assessment and management (2021), recommendations 1.5.1 and 1.5.5 and the KFRE formula (Major 2019 recalibration).
- Official calculator of the KFRE authors (coefficients and baseline survival values).
- Major RW et al. The Kidney Failure Risk Equation for prediction of end stage renal disease in UK primary care. PLoS Med 2019;16(11):e1002955.
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