eGFR (MDRD, legacy) mechanism

Model scope

Educational estimate only and not medical advice, consistent with the supplied honest label. The catalog must explicitly identify whether this is the race-free IDMS-traceable MDRD variant with coefficient 175, rather than another historical MDRD variant.

• The formula is correct for the IDMS-traceable 4-variable MDRD equation without a race coefficient: 175×SCr^-1.154×Age^-0.203×(0.742 if female). However, 'MDRD, legacy' is ambiguous because historical MDRD variants commonly used a 186 coefficient and, in older implementations, an additional Black race coefficient; the intended variant must be named explicitly.
• The input 'sex' is underspecified: the formula defines a female multiplier, but behavior for unknown, nonbinary, or missing values is not stated.

Units and conventions

• Age is in completed years and serum creatinine is in mg/dL.
• The output is normalized to a body-surface area of 1.73 m² and is reported in mL/min/1.73 m².
• If serum creatinine is supplied in µmol/L, convert using SCr_mg/dL = SCr_µmol/L ÷ 88.4 before applying the formula.
• The 0.742 multiplier applies only when the selected formula convention classifies the patient as female; otherwise the multiplier is 1.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "age_years": 60,
    "sex": "male",
    "serum_creatinine_mg_dL": 1
  },
  "expected_outputs": {
    "eGFR_mL_min_1_73m2": 76.22
  },
  "working": "SCr^-1.154 = 1.0^-1.154 = 1.000. Age^-0.203 = 60^-0.203 ≈ 0.43555. Male multiplier = 1.000. eGFR = 175 × 1.000 × 0.43555 × 1.000 = 76.22 mL/min/1.73 m²."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The formula has undefined or non-physiologic boundary inputs that require validation: age = 0 produces an infinite mathematical result, negative serum creatinine produces an undefined real power, and an unspecified creatinine unit can produce an orders-of-magnitude error.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json