HERDOO2 recurrent VTE

HERDOO2

Compute the Rodger 2008 HERDOO2 score (hyperpigmentation, edema, or redness in either leg; D-dimer ≥250 μg/L while on anticoagulants; BMI ≥30; age ≥65) and return whether the derivation classified the patient as low risk (women with score ≤1 only).

LIVE $0.005 USDC GET /api/calc/herdoo2

Markdown: /docs/herdoo2.md · Canonical: https://magentlab.com/docs/herdoo2

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

What it computes

When to use

When an agent needs the published Rodger 2008 HERDOO2 arithmetic after unprovoked VTE and must not invent a duration-of-anticoagulation decision.

When not to use

Not a medical device. magent does not diagnose recurrent VTE or assay D-dimer.
Not a duration-of-anticoagulation order and not a stop-or-continue anticoagulation protocol. low_risk is the Rodger 2008 derivation subgroup, not a treatment instruction.
Men have no low-risk subgroup in the Rodger 2008 derivation. low_risk is false for every male, including score 0.
D-dimer is a caller-assigned ≥250 μg/L flag while on anticoagulants. The derivation used a 250 μg/L cut while on warfarin. magent does not name assay brands.
BMI 30.0 and age 65 each score 1. magent does not compute BMI from height and weight. Recurrence percents are not returned.

Formula

HERDOO2 = her_signs + d_dimer_ge_250 + (bmi_kg_m2>=30) + (age>=65); each 1 if true; max 4; low_risk iff female and score<=1 (men have no low-risk subgroup)

Citation

Title: Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy
Authors: Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Solymoss S, Crowther M, Perrier A, White R, Vickars L, Ramsay T, Betancourt MT, Kovacs MJ
Source: CMAJ. 2008;179(5):417-426
DOI: 10.1503/cmaj.080493

Worked example

Female, no HERDOO2 factors

Given: age=40bmi_kg_m2=22d_dimer_ge_250=falseher_signs=falsesex=female

her_signs false → 0; d_dimer_ge_250 false → 0; BMI 22 is not ≥30 → 0; age 40 is not ≥65 → 0
Score = 0 (max 4); female and score ≤1 → low_risk true

Male with score 0 is not low risk

Given: age=40bmi_kg_m2=22d_dimer_ge_250=falseher_signs=falsesex=male

All four factors absent → score 0
Male → low_risk false regardless of score (no low-risk subgroup in the derivation)

Also searched as

HERDOO2
HERDOO2 score
Rodger HERDOO2
men continue and HERDOO2
unprovoked VTE recurrence HERDOO2
HERDOO2 rule

Try

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

/api/calc/herdoo2?sex=female&her_signs=false&d_dimer_ge_250=false&bmi_kg_m2=22&age=40

Full URL: https://api.magentlab.com/api/calc/herdoo2?sex=female&her_signs=false&d_dimer_ge_250=false&bmi_kg_m2=22&age=40

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/herdoo2?sex=female&her_signs=false&d_dimer_ge_250=false&bmi_kg_m2=22&age=40"

Parameters

Name	Type	Required	Description
`sex`	string	required · female, male	female or male. low_risk is true only when female and score ≤1. Men have no low-risk subgroup in Rodger 2008.
`her_signs`	boolean	required	Hyperpigmentation, edema, or redness in either leg (Rodger 2008). Caller-assigned. true or false. 1 point if true.
`d_dimer_ge_250`	boolean	required	D-dimer ≥250 μg/L while on anticoagulants (Rodger 2008). Caller-assigned; magent does not assay D-dimer. true or false. 1 point if true.
`bmi_kg_m2`	number	required	Body-mass index in kg/m^2 (10-80). Caller-supplied; magent does not compute BMI from height and weight. Scores 1 when ≥30. Equality at 30.0 meets.
`age`	integer	required	Age in years (18-120). Scores 1 when ≥65. Age 65 meets (Rodger 2008).

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/herdoo2 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": "40",
      "bmi_kg_m2": "22",
      "d_dimer_ge_250": "false",
      "her_signs": "false",
      "sex": "female"
    },
    {
      "age": "40",
      "bmi_kg_m2": "22",
      "d_dimer_ge_250": "false",
      "her_signs": "false",
      "sex": "female"
    }
  ]
}

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/herdoo2",
  "items": [
    {
      "components": [
        {
          "factor": "her_signs",
          "points": 0,
          "present": false
        },
        {
          "factor": "d_dimer_ge_250",
          "points": 0,
          "present": false
        },
        {
          "value": 22.0,
          "factor": "bmi_ge_30",
          "points": 0,
          "present": false
        },
        {
          "value": 40,
          "factor": "age_ge_65",
          "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": "Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Solymoss S, Crowther M, Perrier A, White R, Vickars L, Ramsay T, Betancourt MT, Kovacs MJ",
        "doi": "10.1503/cmaj.080493",
        "id": "rodger-2008",
        "pmid": "18725614",
        "source": "CMAJ. 2008;179(5):417-426",
        "title": "Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy"
      },
      "formula": "herdoo2",
      "formula_expression": "HERDOO2 = her_signs + d_dimer_ge_250 + (bmi_kg_m2>=30) + (age>=65); each 1 if true; max 4; low_risk iff female and score<=1 (men have no low-risk subgroup)",
      "age_years": 40,
      "max_score": 4,
      "score": 0,
      "sex": "female",
      "bmi_kg_m2": 22.0,
      "low_risk": true
    },
    {
      "components": [
        {
          "factor": "her_signs",
          "points": 0,
          "present": false
        },
        {
          "factor": "d_dimer_ge_250",
          "points": 0,
          "present": false
        },
        {
          "value": 22.0,
          "factor": "bmi_ge_30",
          "points": 0,
          "present": false
        },
        {
          "value": 40,
          "factor": "age_ge_65",
          "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": "Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Solymoss S, Crowther M, Perrier A, White R, Vickars L, Ramsay T, Betancourt MT, Kovacs MJ",
        "doi": "10.1503/cmaj.080493",
        "id": "rodger-2008",
        "pmid": "18725614",
        "source": "CMAJ. 2008;179(5):417-426",
        "title": "Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy"
      },
      "formula": "herdoo2",
      "formula_expression": "HERDOO2 = her_signs + d_dimer_ge_250 + (bmi_kg_m2>=30) + (age>=65); each 1 if true; max 4; low_risk iff female and score<=1 (men have no low-risk subgroup)",
      "age_years": 40,
      "max_score": 4,
      "score": 0,
      "sex": "female",
      "bmi_kg_m2": 22.0,
      "low_risk": true
    }
  ]
}

Response

Field	Type	Description
`formula`	string	herdoo2
`formula_expression`	string	Exact expression used
`score`	integer	HERDOO2 points 0-4
`max_score`	integer	4
`low_risk`	boolean	true only when sex is female and score ≤1. False for every male, including score 0. Not a stop-or-continue anticoagulation order.
`sex`	string	female or male
`age_years`	integer	Age used for the ≥65 criterion
`bmi_kg_m2`	number	Caller-supplied BMI in kg/m^2 used for the ≥30 criterion
`components`	array	Per-factor points
`citation`	object	Rodger 2008 CMAJ citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "her_signs",
      "points": 0,
      "present": false
    },
    {
      "factor": "d_dimer_ge_250",
      "points": 0,
      "present": false
    },
    {
      "value": 22.0,
      "factor": "bmi_ge_30",
      "points": 0,
      "present": false
    },
    {
      "value": 40,
      "factor": "age_ge_65",
      "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": "Rodger MA, Kahn SR, Wells PS, Anderson DA, Chagnon I, Le Gal G, Solymoss S, Crowther M, Perrier A, White R, Vickars L, Ramsay T, Betancourt MT, Kovacs MJ",
    "doi": "10.1503/cmaj.080493",
    "id": "rodger-2008",
    "pmid": "18725614",
    "source": "CMAJ. 2008;179(5):417-426",
    "title": "Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy"
  },
  "formula": "herdoo2",
  "formula_expression": "HERDOO2 = her_signs + d_dimer_ge_250 + (bmi_kg_m2>=30) + (age>=65); each 1 if true; max 4; low_risk iff female and score<=1 (men have no low-risk subgroup)",
  "age_years": 40,
  "max_score": 4,
  "score": 0,
  "sex": "female",
  "bmi_kg_m2": 22.0,
  "low_risk": true
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_sex`	sex must be female or male Returned before settlement; you are not charged.
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_bmi_kg_m2`	bmi_kg_m2 must be a number from 10 to 80. Returned before settlement; you are not charged.
400	`invalid_age`	age must be an integer from 18 to 120 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

DASH — Compute the Tosetto 2012 DASH score (abnormal D-dimer after stopping anticoagulation, age <50, male sex, hormone use at the initial VTE in women) and return the published recurrence band.
Wells DVT — Compute the Wells deep-vein thrombosis probability score and return three-tier and two-tier bands.

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.