{"uid":"cap_gJOUXuaRG2gkpwyxGh801","slug":"tangri-2011-4-variable-kidney-failure-risk-equation-kfre-f04760f9","name":"Tangri 2011 4-Variable Kidney Failure Risk Equation (KFRE)","description":"Tangri 2011 4-variable Kidney Failure Risk Equation: 2- and 5-year risk of dialysis or transplant from age, male, eGFR, and urine ACR (mg/g). Risk = 1 - S0^exp(LP) with that paper's 4-variable coefficients. Caller supplies eGFR; magent does not compute CKD-EPI or assay ACR. Not the 8-variable model, not Tangri 2016 country S0, no race. Not a dialysis or transplant order. Not a medical device.","url":"https://api.magentlab.com/api/calc/kfre","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["age_years","male","egfr_ml_min","acr_mg_g"],"properties":{"male":{"type":"boolean","description":"true if male, false if female. Enters the linear predictor as 1 or 0 (centered at 0.5642). No race coefficient."},"acr_mg_g":{"type":"number","description":"Urine albumin-to-creatinine ratio in mg/g (0.1-10000, magent clamp; must be positive). Enters as natural log, centered at 5.137. magent does not assay ACR and does not convert from mg/mmol."},"age_years":{"type":"integer","description":"Age in years (18-90, magent clamp). Tangri 2011 4-variable model uses age as a continuous predictor (per 10 years, centered at 7.036). Adult CKD 3-5 derivation."},"egfr_ml_min":{"type":"number","description":"Caller-supplied eGFR in mL/min/1.73 m2 (1-150, magent clamp; must be positive). Tangri 2011 derivation was CKD stages 3-5. magent does not compute CKD-EPI eGFR and does not assay creatinine."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_rL0jWYVeui6Jo2VQhVdWF","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes 2-year and 5-year kidney failure risk (dialysis or transplant) from age, sex, eGFR, and urine ACR using the Tangri 2011 4-variable model.","exampleAgentPrompt":"Calculate the Tangri 2011 4-variable kidney failure risk for a 58-year-old male with an eGFR of 32 mL/min and a urine ACR of 85 mg/g — give me both the 2-year and 5-year risk of dialysis or transplant.","exampleUseCases":[{"title":"CKD nephrology clinic risk stratification","prompt":"My patient is a 72-year-old female with CKD stage 4 — eGFR is 22 mL/min and her urine ACR is 320 mg/g. What are her 2-year and 5-year risks of progressing to dialysis or transplant using the Tangri KFRE?"},{"title":"Primary care annual CKD review","prompt":"I have a 55-year-old male in my primary care panel with stable CKD, eGFR of 48 and ACR of 45 mg/g. Can you run the Tangri 2011 kidney failure risk equation to see whether he needs nephrology referral?"},{"title":"Shared decision-making for dialysis planning","prompt":"A 67-year-old female patient wants to understand her kidney failure risk before we discuss dialysis planning — her eGFR is 18 and urine ACR is 900 mg/g. Give me the 2- and 5-year KFRE probabilities."}],"resultDescription":"Returns the 2-year and 5-year probabilities of kidney failure (dialysis or transplant) computed via the Tangri 2011 four-variable linear predictor and baseline survival function (1 - S0^exp(LP)). Does not return a diagnosis, clinical recommendation, or treatment order.","failureModes":["Missing required query parameter (age_years, male, egfr_ml_min, or acr_mg_g) returns a 400 error","Non-positive or non-numeric values for eGFR or ACR rejected; values are clamped to valid ranges (age 18–90, eGFR 1–150, ACR 0.1–10000)","Payment not attached or insufficient USDC balance returns 402 Payment Required","Caller-supplied eGFR outside physiologically plausible range is clamped silently, not rejected — agent should validate inputs beforehand","ACR in mg/mmol will produce wrong results since the endpoint expects mg/g only"],"whenToPreferThis":"Use this endpoint when you need the validated Tangri 2011 4-variable KFRE specifically — when the caller already has eGFR and ACR in mg/g and wants a peer-reviewed, published risk estimate for adult CKD stages 3–5 without race adjustment. Prefer this over the 8-variable model when cystatin C or other variables are unavailable. Do not use if you need the Tangri 2016 country-calibrated survival functions or need to compute eGFR from creatinine first.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T07:07:22.176Z","isFirstParty":false}