MAGENT

Liver · LIVE

Revised PSC model (Kim 2000)

Revised PSC model

Compute the Kim 2000 revised natural history model R for primary sclerosing cholangitis from age, bilirubin, AST, albumin, and variceal bleeding (no histologic stage).

LIVE $0.005 USDC GET /api/calc/psc_revised

Markdown: /docs/psc-revised.md · Canonical: https://magentlab.com/docs/psc-revised

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

What it computes

Compute the Kim 2000 revised natural history model R for primary sclerosing cholangitis from age, bilirubin, AST, albumin, and variceal bleeding (no histologic stage).

When to use

When an agent needs the published Kim 2000 revised PSC R and must not apply the original Mayo PSC biopsy model, invent survival percents or risk bands, assay labs, diagnose PSC, or treat the result as a transplant listing or biopsy order.

When not to use

  • Not a medical device. magent does not assay labs or diagnose PSC.
  • Not a transplant listing or biopsy order.
  • Kim 2000 revised model only (age, bilirubin, AST, albumin, variceal bleeding). This is not the original Mayo PSC model that used histologic stage.
  • Returns R only. Does not look up Kim 2000 survival-table percents for the computed R and does not invent website risk bands such as low / intermediate / high.

Formula

R = 0.03 * age_years + 0.54 * ln(bilirubin_mg_dl) + 0.54 * ln(ast_u_l) + 1.24 * variceal_bleeding - 0.84 * albumin_g_dl

Citation

Title
A revised natural history model for primary sclerosing cholangitis
Authors
Kim WR, Therneau TM, Wiesner RH, Poterucha JJ, Benson JT, Malinchoc M, LaRusso NF, Lindor KD, Dickson ER
Source
Mayo Clin Proc. 2000;75(7):688-694
DOI
10.4065/75.7.688

Worked example

Age 55, bili 5, AST 120, albumin 3.0, variceal bleeding

Given: age_years=55albumin_g_dl=3.0ast_u_l=120bilirubin_mg_dl=5variceal_bleeding=true

  1. variceal_bleeding = 1
  2. R = 0.03*55 + 0.54*ln(5) + 0.54*ln(120) + 1.24 - 0.84*3.0
  3. round to 2 decimals → 3.82

Age 20, bili 1, AST 20, albumin 4.5, no variceal bleeding

Given: age_years=20albumin_g_dl=4.5ast_u_l=20bilirubin_mg_dl=1variceal_bleeding=false

  1. variceal_bleeding = 0; ln(1) = 0
  2. R = 0.03*20 + 0.54*ln(1) + 0.54*ln(20) + 0 - 0.84*4.5
  3. round to 2 decimals → -1.56

Also searched as

  • revised PSC model
  • Kim PSC score
  • Mayo PSC revised
  • primary sclerosing cholangitis R
  • PSC natural history model
  • revised Mayo PSC
  • PSC variceal bleeding model

Try

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

/api/calc/psc_revised?age_years=55&bilirubin_mg_dl=5&ast_u_l=120&albumin_g_dl=3.0&variceal_bleeding=true

Full URL: https://api.magentlab.com/api/calc/psc_revised?age_years=55&bilirubin_mg_dl=5&ast_u_l=120&albumin_g_dl=3.0&variceal_bleeding=true

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/psc_revised?age_years=55&bilirubin_mg_dl=5&ast_u_l=120&albumin_g_dl=3.0&variceal_bleeding=true"

Parameters

Name Type Required Description
age_years integer required Age in whole years (18-120, magent clamp). Kim 2000 uses age in years in the R equation.
bilirubin_mg_dl number required Total bilirubin in mg/dL (0.1-40, magent clamp). Must be positive; natural log is undefined at 0. Kim 2000 uses mg/dL. magent does not assay bilirubin.
ast_u_l number required Aspartate aminotransferase in U/L (1-10000, magent clamp). Must be positive. magent does not assay AST.
albumin_g_dl number required Serum albumin in g/dL (1.0-6.0, magent clamp). Must be positive. Kim 2000 uses g/dL. magent does not assay albumin.
variceal_bleeding boolean required History of variceal bleeding as assigned by the caller (Kim 2000): true (1) or false (0). magent does not diagnose bleeding.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/psc_revised Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

  • 1 to 25 items. Each item uses the same keys as the GET query parameters.
  • POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
  • 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": [
    {
      "age_years": "55",
      "albumin_g_dl": "3.0",
      "ast_u_l": "120",
      "bilirubin_mg_dl": "5",
      "variceal_bleeding": "true"
    },
    {
      "age_years": "55",
      "albumin_g_dl": "3.0",
      "ast_u_l": "120",
      "bilirubin_mg_dl": "5",
      "variceal_bleeding": "true"
    }
  ]
}

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/psc_revised",
  "items": [
    {
      "r": 3.82,
      "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": "Kim WR, Therneau TM, Wiesner RH, Poterucha JJ, Benson JT, Malinchoc M, LaRusso NF, Lindor KD, Dickson ER",
        "doi": "10.4065/75.7.688",
        "id": "kim-2000",
        "pmid": "10907383",
        "source": "Mayo Clin Proc. 2000;75(7):688-694",
        "title": "A revised natural history model for primary sclerosing cholangitis"
      },
      "formula": "kim_psc_revised_2000",
      "formula_expression": "R = 0.03 * age_years + 0.54 * ln(bilirubin_mg_dl) + 0.54 * ln(ast_u_l) + 1.24 * variceal_bleeding - 0.84 * albumin_g_dl",
      "albumin_g_dl": 3.0,
      "age_years": 55,
      "ast_u_l": 120.0,
      "bilirubin_mg_dl": 5.0,
      "variceal_bleeding": true
    },
    {
      "r": 3.82,
      "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": "Kim WR, Therneau TM, Wiesner RH, Poterucha JJ, Benson JT, Malinchoc M, LaRusso NF, Lindor KD, Dickson ER",
        "doi": "10.4065/75.7.688",
        "id": "kim-2000",
        "pmid": "10907383",
        "source": "Mayo Clin Proc. 2000;75(7):688-694",
        "title": "A revised natural history model for primary sclerosing cholangitis"
      },
      "formula": "kim_psc_revised_2000",
      "formula_expression": "R = 0.03 * age_years + 0.54 * ln(bilirubin_mg_dl) + 0.54 * ln(ast_u_l) + 1.24 * variceal_bleeding - 0.84 * albumin_g_dl",
      "albumin_g_dl": 3.0,
      "age_years": 55,
      "ast_u_l": 120.0,
      "bilirubin_mg_dl": 5.0,
      "variceal_bleeding": true
    }
  ]
}

Response

Field Type Description
formula string kim_psc_revised_2000
formula_expression string Exact expression used
age_years integer Age used, whole years
bilirubin_mg_dl number Total bilirubin used in mg/dL
ast_u_l number AST used in U/L
albumin_g_dl number Albumin used in g/dL
variceal_bleeding boolean true if variceal bleeding history is present (coefficient 1.24)
r number Kim 2000 revised PSC R, 2 decimals. Natural log. No survival-table lookup and no invented risk bands.
citation object Kim 2000 Mayo Clin Proc citation
disclaimer string Not-a-device notice

Example JSON

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

{
  "r": 3.82,
  "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": "Kim WR, Therneau TM, Wiesner RH, Poterucha JJ, Benson JT, Malinchoc M, LaRusso NF, Lindor KD, Dickson ER",
    "doi": "10.4065/75.7.688",
    "id": "kim-2000",
    "pmid": "10907383",
    "source": "Mayo Clin Proc. 2000;75(7):688-694",
    "title": "A revised natural history model for primary sclerosing cholangitis"
  },
  "formula": "kim_psc_revised_2000",
  "formula_expression": "R = 0.03 * age_years + 0.54 * ln(bilirubin_mg_dl) + 0.54 * ln(ast_u_l) + 1.24 * variceal_bleeding - 0.84 * albumin_g_dl",
  "albumin_g_dl": 3.0,
  "age_years": 55,
  "ast_u_l": 120.0,
  "bilirubin_mg_dl": 5.0,
  "variceal_bleeding": true
}

Client errors (HTTP 400)

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

HTTP Code When
400 invalid_psc_revised Revised PSC model inputs must be numeric age, bilirubin, AST, and albumin plus variceal-bleeding as used in Kim 2000. Returned before settlement; you are not charged.
400 invalid_items POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400 invalid_item_count items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400 invalid_item each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

  • MELD — Compute the Kamath 2001 model for end-stage liver disease (MELD) integer from creatinine, bilirubin, INR, and cholestatic or alcoholic etiology.
  • Child–Pugh — Compute the Child–Turcotte–Pugh cirrhosis severity score from bilirubin, albumin, INR, encephalopathy, and ascites.

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, 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

  • HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
  • exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. 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.