IMPROVE VTE associative score

IMPROVE VTE

Compute the Spyropoulos 2011 7-factor associative IMPROVE VTE score during hospitalization from age and six caller-assigned flags.

LIVE $0.005 USDC GET /api/calc/improve_vte

Markdown: /docs/improve-vte.md · Canonical: https://magentlab.com/docs/improve-vte

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

What it computes

Compute the Spyropoulos 2011 7-factor associative IMPROVE VTE score during hospitalization from age and six caller-assigned flags.

When to use

When an agent needs the published 7-factor associative IMPROVE VTE score during hospitalization (not the 4-factor admission predictive model, not IMPROVEDD, not Padua, not Caprini). magent does not examine the patient and does not diagnose VTE or issue a prophylaxis order.

When not to use

Not a medical device.
Not a VTE diagnosis. magent does not diagnose venous thromboembolism.
Not a prophylaxis order. This tool does not recommend a drug or start thromboprophylaxis.
7-factor associative IMPROVE VTE score during hospitalization (Spyropoulos 2011). Observed VTE in the paper was 1.5% at score 2-3 and 5.7% at score >=4; score >=2 was associated with higher mortality. Those figures are published associations, not per-integer rates and not a treatment threshold.
Not the 4-factor admission-only predictive model. Not IMPROVEDD (no D-dimer).
Not Padua or Caprini.
magent does not examine the patient. Flags are caller-assigned.

Formula

IMPROVE VTE (Spyropoulos 2011 7-factor associative during hospitalization) = previous_vte (3) + known_thrombophilia (2) + lower_limb_paralysis (2) + current_cancer (2) + immobilized_ge_7_days (1) + icu_ccu_stay (1) + age>60 (1); max 12; 0-1, 2-3 (observed VTE 1.5%), >=4 (observed VTE 5.7%); not the 4-factor admission predictive model; not IMPROVEDD

Citation

Title: Predictive and associative models to identify hospitalized medical patients at risk for VTE
Authors: Spyropoulos AC, Anderson FA Jr, FitzGerald G, Decousus H, Pini M, Chong BH, Zotz RB, Bergmann JF, Tapson VF, Froehlich JB, Monreal M, Merli GJ, Pavanello R, Turpie AGG, Nakamura M, Piovella F, Kakkar AK, Spencer FA, IMPROVE Investigators
Source: Chest. 2011;140(3):706-714
DOI: 10.1378/chest.10-1944

Worked example

Age 50, all flags false

Given: age=50current_cancer=falseicu_ccu_stay=falseimmobilized_ge_7_days=falseknown_thrombophilia=falselower_limb_paralysis=falseprevious_vte=false

Age 50 is not >60 → 0; all six flags false → 0
Score = 0 (max 12); vte_band 0-1

Previous VTE plus current cancer is >=4

Given: age=50current_cancer=trueicu_ccu_stay=falseimmobilized_ge_7_days=falseknown_thrombophilia=falselower_limb_paralysis=falseprevious_vte=true

previous_vte → 3; current_cancer → 2; age 50 not >60 → 0
Score = 5 (max 12); vte_band >=4

Also searched as

IMPROVE VTE score
IMPROVE associative VTE
Spyropoulos IMPROVE
hospital VTE risk
IMPROVE medical VTE
7-factor IMPROVE VTE
associative IMPROVE VTE

Try

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

/api/calc/improve_vte?age=50&previous_vte=false&known_thrombophilia=false&lower_limb_paralysis=false&current_cancer=false&immobilized_ge_7_days=false&icu_ccu_stay=false

Full URL: https://api.magentlab.com/api/calc/improve_vte?age=50&previous_vte=false&known_thrombophilia=false&lower_limb_paralysis=false&current_cancer=false&immobilized_ge_7_days=false&icu_ccu_stay=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/improve_vte?age=50&previous_vte=false&known_thrombophilia=false&lower_limb_paralysis=false&current_cancer=false&immobilized_ge_7_days=false&icu_ccu_stay=false"

Parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (18-120). Scores 1 when age >60 (Spyropoulos 2011). Age 60 scores 0; age 61 scores 1.
`previous_vte`	boolean	required	Previous VTE as assigned by the caller (Spyropoulos 2011 7-factor associative model). true or false. 3 points if true. magent does not diagnose VTE.
`known_thrombophilia`	boolean	required	Known thrombophilia as assigned by the caller (Spyropoulos 2011). true or false. 2 points if true. magent does not interpret a thrombophilia panel.
`lower_limb_paralysis`	boolean	required	Lower-limb paralysis as assigned by the caller (Spyropoulos 2011). true or false. 2 points if true. magent does not examine the patient.
`current_cancer`	boolean	required	Current cancer as assigned by the caller (Spyropoulos 2011). true or false. 2 points if true. magent does not diagnose cancer.
`immobilized_ge_7_days`	boolean	required	Immobilized ≥7 days as assigned by the caller (Spyropoulos 2011, during hospitalization). true or false. 1 point if true. magent does not observe mobility.
`icu_ccu_stay`	boolean	required	ICU or CCU stay as assigned by the caller (Spyropoulos 2011, during hospitalization). true or false. 1 point if true. magent does not assign level of care.

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/improve_vte 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": "50",
      "current_cancer": "false",
      "icu_ccu_stay": "false",
      "immobilized_ge_7_days": "false",
      "known_thrombophilia": "false",
      "lower_limb_paralysis": "false",
      "previous_vte": "false"
    },
    {
      "age": "50",
      "current_cancer": "false",
      "icu_ccu_stay": "false",
      "immobilized_ge_7_days": "false",
      "known_thrombophilia": "false",
      "lower_limb_paralysis": "false",
      "previous_vte": "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/improve_vte",
  "items": [
    {
      "components": [
        {
          "factor": "previous_vte",
          "points": 0,
          "present": false
        },
        {
          "factor": "known_thrombophilia",
          "points": 0,
          "present": false
        },
        {
          "factor": "lower_limb_paralysis",
          "points": 0,
          "present": false
        },
        {
          "factor": "current_cancer",
          "points": 0,
          "present": false
        },
        {
          "factor": "immobilized_ge_7_days",
          "points": 0,
          "present": false
        },
        {
          "factor": "icu_ccu_stay",
          "points": 0,
          "present": false
        },
        {
          "value": 50,
          "factor": "age_gt_60",
          "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.",
      "age_years": 50,
      "citation": {
        "authors": "Spyropoulos AC, Anderson FA Jr, FitzGerald G, Decousus H, Pini M, Chong BH, Zotz RB, Bergmann JF, Tapson VF, Froehlich JB, Monreal M, Merli GJ, Pavanello R, Turpie AGG, Nakamura M, Piovella F, Kakkar AK, Spencer FA, IMPROVE Investigators",
        "doi": "10.1378/chest.10-1944",
        "id": "spyropoulos-2011",
        "pmid": "21436241",
        "source": "Chest. 2011;140(3):706-714",
        "title": "Predictive and associative models to identify hospitalized medical patients at risk for VTE"
      },
      "formula": "improve_vte",
      "formula_expression": "IMPROVE VTE (Spyropoulos 2011 7-factor associative during hospitalization) = previous_vte (3) + known_thrombophilia (2) + lower_limb_paralysis (2) + current_cancer (2) + immobilized_ge_7_days (1) + icu_ccu_stay (1) + age>60 (1); max 12; 0-1, 2-3 (observed VTE 1.5%), >=4 (observed VTE 5.7%); not the 4-factor admission predictive model; not IMPROVEDD",
      "max_score": 12,
      "score": 0,
      "vte_band": "0-1"
    },
    {
      "components": [
        {
          "factor": "previous_vte",
          "points": 0,
          "present": false
        },
        {
          "factor": "known_thrombophilia",
          "points": 0,
          "present": false
        },
        {
          "factor": "lower_limb_paralysis",
          "points": 0,
          "present": false
        },
        {
          "factor": "current_cancer",
          "points": 0,
          "present": false
        },
        {
          "factor": "immobilized_ge_7_days",
          "points": 0,
          "present": false
        },
        {
          "factor": "icu_ccu_stay",
          "points": 0,
          "present": false
        },
        {
          "value": 50,
          "factor": "age_gt_60",
          "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.",
      "age_years": 50,
      "citation": {
        "authors": "Spyropoulos AC, Anderson FA Jr, FitzGerald G, Decousus H, Pini M, Chong BH, Zotz RB, Bergmann JF, Tapson VF, Froehlich JB, Monreal M, Merli GJ, Pavanello R, Turpie AGG, Nakamura M, Piovella F, Kakkar AK, Spencer FA, IMPROVE Investigators",
        "doi": "10.1378/chest.10-1944",
        "id": "spyropoulos-2011",
        "pmid": "21436241",
        "source": "Chest. 2011;140(3):706-714",
        "title": "Predictive and associative models to identify hospitalized medical patients at risk for VTE"
      },
      "formula": "improve_vte",
      "formula_expression": "IMPROVE VTE (Spyropoulos 2011 7-factor associative during hospitalization) = previous_vte (3) + known_thrombophilia (2) + lower_limb_paralysis (2) + current_cancer (2) + immobilized_ge_7_days (1) + icu_ccu_stay (1) + age>60 (1); max 12; 0-1, 2-3 (observed VTE 1.5%), >=4 (observed VTE 5.7%); not the 4-factor admission predictive model; not IMPROVEDD",
      "max_score": 12,
      "score": 0,
      "vte_band": "0-1"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	improve_vte
`formula_expression`	string	Exact expression used
`score`	integer	Total points 0-12
`max_score`	integer	Always 12
`vte_band`	string	Spyropoulos 2011 observed-VTE band during hospitalization: 0-1, 2-3, or >=4. Not a diagnosis and not a prophylaxis order.
`age_years`	integer	Age used for the >60 criterion
`components`	array	Per-item points
`citation`	object	Spyropoulos 2011 citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "previous_vte",
      "points": 0,
      "present": false
    },
    {
      "factor": "known_thrombophilia",
      "points": 0,
      "present": false
    },
    {
      "factor": "lower_limb_paralysis",
      "points": 0,
      "present": false
    },
    {
      "factor": "current_cancer",
      "points": 0,
      "present": false
    },
    {
      "factor": "immobilized_ge_7_days",
      "points": 0,
      "present": false
    },
    {
      "factor": "icu_ccu_stay",
      "points": 0,
      "present": false
    },
    {
      "value": 50,
      "factor": "age_gt_60",
      "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.",
  "age_years": 50,
  "citation": {
    "authors": "Spyropoulos AC, Anderson FA Jr, FitzGerald G, Decousus H, Pini M, Chong BH, Zotz RB, Bergmann JF, Tapson VF, Froehlich JB, Monreal M, Merli GJ, Pavanello R, Turpie AGG, Nakamura M, Piovella F, Kakkar AK, Spencer FA, IMPROVE Investigators",
    "doi": "10.1378/chest.10-1944",
    "id": "spyropoulos-2011",
    "pmid": "21436241",
    "source": "Chest. 2011;140(3):706-714",
    "title": "Predictive and associative models to identify hospitalized medical patients at risk for VTE"
  },
  "formula": "improve_vte",
  "formula_expression": "IMPROVE VTE (Spyropoulos 2011 7-factor associative during hospitalization) = previous_vte (3) + known_thrombophilia (2) + lower_limb_paralysis (2) + current_cancer (2) + immobilized_ge_7_days (1) + icu_ccu_stay (1) + age>60 (1); max 12; 0-1, 2-3 (observed VTE 1.5%), >=4 (observed VTE 5.7%); not the 4-factor admission predictive model; not IMPROVEDD",
  "max_score": 12,
  "score": 0,
  "vte_band": "0-1"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_age`	age must be an integer from 18 to 120 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_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

Padua score — Compute the Barbar 2010 Padua Prediction Score for VTE risk in hospitalized medical patients from age and ten caller-assigned findings.
Caprini score — Sum Caprini 2005 Table 3 thrombosis risk factors with exclusive age and surgery weights and return the Table 2 band (low / moderate / high / highest).
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.