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Travis criteria for severe ulcerative colitis

Travis criteria

Apply the Travis 1996 day-3 of intravenous corticosteroids rule for severe ulcerative colitis and return travis_high from stools_per_day and crp_mg_l.

LIVE $0.005 USDC GET /api/calc/travis

Markdown: /docs/travis.md · Canonical: https://magentlab.com/docs/travis

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

What it computes

Apply the Travis 1996 day-3 of intravenous corticosteroids rule for severe ulcerative colitis and return travis_high from stools_per_day and crp_mg_l.

When to use

When an agent already has the day-3 stool count and CRP in mg/L during intravenous steroid treatment for severe ulcerative colitis and needs the published Travis 1996 high-risk classification. magent does not count stools or measure CRP.

When not to use

• Not a medical device.
• Not a colectomy order. magent does not assign surgery or return a colectomy probability.
• This is Travis 1996 day-3 of intravenous steroids for severe ulcerative colitis only. Not the Ho score. Not Truelove and Witts.
• The caller assigns stools_per_day and crp_mg_l. magent does not count stools or measure CRP.

Formula

travis_high iff stools_per_day > 8 or (stools_per_day in 3-8 inclusive and crp_mg_l > 45) (Travis 1996 day-3 of IV steroids for severe UC)

Citation

Title

Predicting outcome in severe ulcerative colitis

Authors

Travis SPL, Farrant JM, Ricketts C, Nolan DJ, Mortensen NM, Kettlewell MGW, Jewell DP

Source

Gut. 1996;38(6):905-910

DOI

10.1136/gut.38.6.905

Worked example

Also searched as

• Travis criteria
• Travis 1996
• day-3 IV steroids UC
• severe ulcerative colitis Travis
• Travis CRP stools
• Travis index ulcerative colitis
• Oxford day-3 criteria
• Travis simple criteria

Try

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

/api/calc/travis?stools_per_day=9&crp_mg_l=10

Full URL: https://api.magentlab.com/api/calc/travis?stools_per_day=9&crp_mg_l=10

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/travis?stools_per_day=9&crp_mg_l=10"

Parameters

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/travis 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": [
    {
      "crp_mg_l": "10",
      "stools_per_day": "9"
    },
    {
      "crp_mg_l": "10",
      "stools_per_day": "9"
    }
  ]
}

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/travis",
  "items": [
    {
      "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": "Travis SPL, Farrant JM, Ricketts C, Nolan DJ, Mortensen NM, Kettlewell MGW, Jewell DP",
        "doi": "10.1136/gut.38.6.905",
        "id": "travis-1996",
        "pmid": "8984031",
        "source": "Gut. 1996;38(6):905-910",
        "title": "Predicting outcome in severe ulcerative colitis"
      },
      "formula": "travis",
      "formula_expression": "travis_high iff stools_per_day > 8 or (stools_per_day in 3-8 inclusive and crp_mg_l > 45) (Travis 1996 day-3 of IV steroids for severe UC)",
      "crp_mg_l": 10.0,
      "criteria": [
        {
          "value": 9,
          "factor": "stools_gt_8",
          "met": true
        },
        {
          "factor": "stools_3_to_8_and_crp_gt_45",
          "crp_mg_l": 10.0,
          "met": false,
          "stools_per_day": 9
        }
      ],
      "stools_per_day": 9,
      "travis_high": true
    },
    {
      "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": "Travis SPL, Farrant JM, Ricketts C, Nolan DJ, Mortensen NM, Kettlewell MGW, Jewell DP",
        "doi": "10.1136/gut.38.6.905",
        "id": "travis-1996",
        "pmid": "8984031",
        "source": "Gut. 1996;38(6):905-910",
        "title": "Predicting outcome in severe ulcerative colitis"
      },
      "formula": "travis",
      "formula_expression": "travis_high iff stools_per_day > 8 or (stools_per_day in 3-8 inclusive and crp_mg_l > 45) (Travis 1996 day-3 of IV steroids for severe UC)",
      "crp_mg_l": 10.0,
      "criteria": [
        {
          "value": 9,
          "factor": "stools_gt_8",
          "met": true
        },
        {
          "factor": "stools_3_to_8_and_crp_gt_45",
          "crp_mg_l": 10.0,
          "met": false,
          "stools_per_day": 9
        }
      ],
      "stools_per_day": 9,
      "travis_high": true
    }
  ]
}

Response

Example JSON

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

{
  "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": "Travis SPL, Farrant JM, Ricketts C, Nolan DJ, Mortensen NM, Kettlewell MGW, Jewell DP",
    "doi": "10.1136/gut.38.6.905",
    "id": "travis-1996",
    "pmid": "8984031",
    "source": "Gut. 1996;38(6):905-910",
    "title": "Predicting outcome in severe ulcerative colitis"
  },
  "formula": "travis",
  "formula_expression": "travis_high iff stools_per_day > 8 or (stools_per_day in 3-8 inclusive and crp_mg_l > 45) (Travis 1996 day-3 of IV steroids for severe UC)",
  "crp_mg_l": 10.0,
  "criteria": [
    {
      "value": 9,
      "factor": "stools_gt_8",
      "met": true
    },
    {
      "factor": "stools_3_to_8_and_crp_gt_45",
      "crp_mg_l": 10.0,
      "met": false,
      "stools_per_day": 9
    }
  ],
  "stools_per_day": 9,
  "travis_high": true
}

Client errors (HTTP 400)

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

Related tools

• Truelove and Witts — Apply the Truelove and Witts 1955 ulcerative colitis severity table and return mild, moderately_severe, or severe from stools_per_day and five caller-assigned flags.
• Mayo DAI — Sum four caller-assigned Schroeder 1987 ulcerative colitis disease-activity index items (each integer 0-3) and return the total (max 12). Does not return later remission or activity bands.
• PUCAI — Sum six caller-assigned Turner 2007 PUCAI item points and return the published total (max 85) with activity band.

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.