Infection / VTE · LIVE

Wells DVT probability score

Wells DVT

Compute the Wells deep-vein thrombosis probability score and return three-tier and two-tier bands.

LIVE $0.005 USDC GET /api/calc/wells_dvt

Markdown: /docs/wells-dvt.md · Canonical: https://magentlab.com/docs/wells-dvt

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

What it computes

Compute the Wells deep-vein thrombosis probability score and return three-tier and two-tier bands.

When to use

When an agent needs the published Wells DVT arithmetic and must not invent a probability from prose.

When not to use

Not a diagnosis. Bands are published cut-points, not a DVT rule-out.
alternative_diagnosis_as_likely subtracts 2. Flags are caller-supplied booleans.

Formula

Wells DVT = +1 each of 9 findings; −2 if alternative_diagnosis_as_likely

Citation

Title: Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis
Authors: Wells PS, Anderson DR, Rodger M, et al.
Source: N Engl J Med. 2003;349(13):1227-1235
DOI: 10.1056/NEJMoa023153

Worked example

Active cancer + calf swelling

Given: active_cancer=truealternative_diagnosis_as_likely=falsebedridden_or_surgery=falsecalf_swelling_gt_3cm=truecollateral_veins=falseentire_leg_swollen=falseparalysis_or_cast=falsepitting_edema=falseprevious_dvt=falsetenderness=false

active_cancer → +1; calf_swelling_gt_3cm → +1
Score = 2 → three-tier moderate, two-tier likely (≥2)

Also searched as

Wells DVT score
Wells deep vein thrombosis
DVT likely unlikely
Wells DVT two-tier

Try

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

/api/calc/wells_dvt?active_cancer=true&paralysis_or_cast=false&bedridden_or_surgery=false&tenderness=false&entire_leg_swollen=false&calf_swelling_gt_3cm=true&pitting_edema=false&collateral_veins=false&previous_dvt=false&alternative_diagnosis_as_likely=false

Full URL: https://api.magentlab.com/api/calc/wells_dvt?active_cancer=true&paralysis_or_cast=false&bedridden_or_surgery=false&tenderness=false&entire_leg_swollen=false&calf_swelling_gt_3cm=true&pitting_edema=false&collateral_veins=false&previous_dvt=false&alternative_diagnosis_as_likely=false

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/wells_dvt?active_cancer=true&paralysis_or_cast=false&bedridden_or_surgery=false&tenderness=false&entire_leg_swollen=false&calf_swelling_gt_3cm=true&pitting_edema=false&collateral_veins=false&previous_dvt=false&alternative_diagnosis_as_likely=false"

Parameters

Name	Type	Required	Description
`active_cancer`	boolean	required	Active cancer (treatment ongoing, within 6 months, or palliative). +1.
`paralysis_or_cast`	boolean	required	Paralysis, paresis, or recent plaster immobilization of the legs. +1.
`bedridden_or_surgery`	boolean	required	Recently bedridden ≥3 days or major surgery within 12 weeks. +1.
`tenderness`	boolean	required	Localized tenderness along the deep venous system. +1.
`entire_leg_swollen`	boolean	required	Entire leg swollen. +1.
`calf_swelling_gt_3cm`	boolean	required	Calf swelling >3 cm compared with the asymptomatic side. +1.
`pitting_edema`	boolean	required	Pitting edema confined to the symptomatic leg. +1.
`collateral_veins`	boolean	required	Collateral superficial veins (nonvaricose). +1.
`previous_dvt`	boolean	required	Previously documented DVT. +1.
`alternative_diagnosis_as_likely`	boolean	required	Alternative diagnosis at least as likely as DVT. −2.

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/wells_dvt 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": [
    {
      "active_cancer": "true",
      "alternative_diagnosis_as_likely": "false",
      "bedridden_or_surgery": "false",
      "calf_swelling_gt_3cm": "true",
      "collateral_veins": "false",
      "entire_leg_swollen": "false",
      "paralysis_or_cast": "false",
      "pitting_edema": "false",
      "previous_dvt": "false",
      "tenderness": "false"
    },
    {
      "active_cancer": "true",
      "alternative_diagnosis_as_likely": "false",
      "bedridden_or_surgery": "false",
      "calf_swelling_gt_3cm": "true",
      "collateral_veins": "false",
      "entire_leg_swollen": "false",
      "paralysis_or_cast": "false",
      "pitting_edema": "false",
      "previous_dvt": "false",
      "tenderness": "false"
    }
  ]
}

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/wells_dvt",
  "items": [
    {
      "components": [
        {
          "factor": "active_cancer",
          "points": 1,
          "present": true
        },
        {
          "factor": "paralysis_or_cast",
          "points": 0,
          "present": false
        },
        {
          "factor": "bedridden_or_surgery",
          "points": 0,
          "present": false
        },
        {
          "factor": "tenderness",
          "points": 0,
          "present": false
        },
        {
          "factor": "entire_leg_swollen",
          "points": 0,
          "present": false
        },
        {
          "factor": "calf_swelling_gt_3cm",
          "points": 1,
          "present": true
        },
        {
          "factor": "pitting_edema",
          "points": 0,
          "present": false
        },
        {
          "factor": "collateral_veins",
          "points": 0,
          "present": false
        },
        {
          "factor": "previous_dvt",
          "points": 0,
          "present": false
        },
        {
          "factor": "alternative_diagnosis_as_likely",
          "points": 0,
          "present": false
        }
      ],
      "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": "Wells PS, Anderson DR, Rodger M, et al.",
        "doi": "10.1056/NEJMoa023153",
        "id": "wells-dvt-2003",
        "source": "N Engl J Med. 2003;349(13):1227-1235",
        "title": "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis"
      },
      "formula": "wells_dvt",
      "formula_expression": "Wells DVT = +1 each of 9 findings; −2 if alternative_diagnosis_as_likely",
      "max_score": 9,
      "score": 2,
      "three_tier": "moderate",
      "two_tier": "likely"
    },
    {
      "components": [
        {
          "factor": "active_cancer",
          "points": 1,
          "present": true
        },
        {
          "factor": "paralysis_or_cast",
          "points": 0,
          "present": false
        },
        {
          "factor": "bedridden_or_surgery",
          "points": 0,
          "present": false
        },
        {
          "factor": "tenderness",
          "points": 0,
          "present": false
        },
        {
          "factor": "entire_leg_swollen",
          "points": 0,
          "present": false
        },
        {
          "factor": "calf_swelling_gt_3cm",
          "points": 1,
          "present": true
        },
        {
          "factor": "pitting_edema",
          "points": 0,
          "present": false
        },
        {
          "factor": "collateral_veins",
          "points": 0,
          "present": false
        },
        {
          "factor": "previous_dvt",
          "points": 0,
          "present": false
        },
        {
          "factor": "alternative_diagnosis_as_likely",
          "points": 0,
          "present": false
        }
      ],
      "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": "Wells PS, Anderson DR, Rodger M, et al.",
        "doi": "10.1056/NEJMoa023153",
        "id": "wells-dvt-2003",
        "source": "N Engl J Med. 2003;349(13):1227-1235",
        "title": "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis"
      },
      "formula": "wells_dvt",
      "formula_expression": "Wells DVT = +1 each of 9 findings; −2 if alternative_diagnosis_as_likely",
      "max_score": 9,
      "score": 2,
      "three_tier": "moderate",
      "two_tier": "likely"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	wells_dvt
`formula_expression`	string	Exact expression used
`score`	integer	Total points (−2 to 9)
`max_score`	integer	Always 9
`three_tier`	string	low (≤0), moderate (1-2), high (≥3). Not a diagnosis.
`two_tier`	string	likely (≥2) or unlikely (<2). Not a diagnosis.
`components`	array	Per-factor points
`citation`	object	NEJM 2003 citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "active_cancer",
      "points": 1,
      "present": true
    },
    {
      "factor": "paralysis_or_cast",
      "points": 0,
      "present": false
    },
    {
      "factor": "bedridden_or_surgery",
      "points": 0,
      "present": false
    },
    {
      "factor": "tenderness",
      "points": 0,
      "present": false
    },
    {
      "factor": "entire_leg_swollen",
      "points": 0,
      "present": false
    },
    {
      "factor": "calf_swelling_gt_3cm",
      "points": 1,
      "present": true
    },
    {
      "factor": "pitting_edema",
      "points": 0,
      "present": false
    },
    {
      "factor": "collateral_veins",
      "points": 0,
      "present": false
    },
    {
      "factor": "previous_dvt",
      "points": 0,
      "present": false
    },
    {
      "factor": "alternative_diagnosis_as_likely",
      "points": 0,
      "present": false
    }
  ],
  "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": "Wells PS, Anderson DR, Rodger M, et al.",
    "doi": "10.1056/NEJMoa023153",
    "id": "wells-dvt-2003",
    "source": "N Engl J Med. 2003;349(13):1227-1235",
    "title": "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis"
  },
  "formula": "wells_dvt",
  "formula_expression": "Wells DVT = +1 each of 9 findings; −2 if alternative_diagnosis_as_likely",
  "max_score": 9,
  "score": 2,
  "three_tier": "moderate",
  "two_tier": "likely"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_flag`	boolean clinical flags must be true or false 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

Wells PE — Compute the Wells pulmonary-embolism probability score and return three-tier and two-tier bands.
CURB-65 — Compute the CURB-65 community-acquired pneumonia severity score from age and discrete flags.

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.