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Schwartz 2009 bedside eGFR

Schwartz 2009 eGFR

Compute the 2009 Schwartz bedside CKiD eGFR in mL/min/1.73m2 from height and serum creatinine.

LIVE $0.005 USDC GET /api/calc/schwartz_gfr

Markdown: /docs/schwartz-gfr.md · Canonical: https://magentlab.com/docs/schwartz-gfr

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute the 2009 Schwartz bedside CKiD eGFR in mL/min/1.73m2 from height and serum creatinine.

When to use

When an agent needs pediatric eGFR from the 2009 CKiD bedside equation and must not invent CKD-EPI, Cockcroft–Gault, or the 1976 Schwartz k=0.55 formula.

When not to use

• Not a dosing recommendation. Validated in the pediatric CKiD (Chronic Kidney Disease in Children) cohort; not an adult CKD-EPI or Cockcroft–Gault equation.
• This is the 2009 bedside formula (k=0.413). It is not the 1976 Schwartz k=0.55 formula and does not use cystatin C, BUN, age, or sex.
• Does not assign CKD stages.

Formula

egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl

Citation

Title

New equations to estimate GFR in children with CKD

Authors

Schwartz GJ, Muñoz A, Schneider MF, et al.

Source

J Am Soc Nephrol. 2009;20(3):629-637

DOI

10.1681/ASN.2008030287

Worked example

Also searched as

• Schwartz 2009
• bedside Schwartz
• CKiD eGFR
• pediatric eGFR
• revised Schwartz
• Schwartz GFR
• 0.413 height creatinine

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/schwartz_gfr?height_cm=140&creatinine_mg_dl=1.0

Full URL: https://api.magentlab.com/api/calc/schwartz_gfr?height_cm=140&creatinine_mg_dl=1.0

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/schwartz_gfr?height_cm=140&creatinine_mg_dl=1.0"

Parameters

Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

POST /api/calc/schwartz_gfr Max 25 unit_amount * n PREVIEW

• 1 to 25 items. Each item uses the same keys as the GET query parameters.
• The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
• HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
• Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
• x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "creatinine_mg_dl": "1.0",
      "height_cm": "140"
    },
    {
      "creatinine_mg_dl": "1.0",
      "height_cm": "140"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/schwartz_gfr",
  "items": [
    {
      "units": "mL/min/1.73m2",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Schwartz GJ, Muñoz A, Schneider MF, et al.",
        "doi": "10.1681/ASN.2008030287",
        "id": "schwartz-2009",
        "source": "J Am Soc Nephrol. 2009;20(3):629-637",
        "title": "New equations to estimate GFR in children with CKD"
      },
      "formula": "schwartz_2009",
      "formula_expression": "egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl",
      "height_cm": 140.0,
      "creatinine_mg_dl": 1.0,
      "egfr_ml_min_1_73m2": 57.8
    },
    {
      "units": "mL/min/1.73m2",
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Schwartz GJ, Muñoz A, Schneider MF, et al.",
        "doi": "10.1681/ASN.2008030287",
        "id": "schwartz-2009",
        "source": "J Am Soc Nephrol. 2009;20(3):629-637",
        "title": "New equations to estimate GFR in children with CKD"
      },
      "formula": "schwartz_2009",
      "formula_expression": "egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl",
      "height_cm": 140.0,
      "creatinine_mg_dl": 1.0,
      "egfr_ml_min_1_73m2": 57.8
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "units": "mL/min/1.73m2",
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Schwartz GJ, Muñoz A, Schneider MF, et al.",
    "doi": "10.1681/ASN.2008030287",
    "id": "schwartz-2009",
    "source": "J Am Soc Nephrol. 2009;20(3):629-637",
    "title": "New equations to estimate GFR in children with CKD"
  },
  "formula": "schwartz_2009",
  "formula_expression": "egfr_ml_min_1_73m2 = 0.413 * height_cm / creatinine_mg_dl",
  "height_cm": 140.0,
  "creatinine_mg_dl": 1.0,
  "egfr_ml_min_1_73m2": 57.8
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• CKD-EPI 2021 eGFR — Compute race-free CKD-EPI 2021 creatinine eGFR in mL/min/1.73m2.
• Cockcroft–Gault CrCl — Compute Cockcroft–Gault creatinine clearance in mL/min using total body weight.

Payment

Required query parameters must be present and valid. Invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

• Invalid query parameters return HTTP 400 before settlement. You are not charged.
• Settlement finishes before the tool executes (paymentFlow upfront). Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
• HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
• Execution is timeout-bounded and concurrency-capped.
• Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.