DRAGON score

DRAGON

Compute the Strbian 2012 DRAGON score (Dense artery / early infarct signs, prestroke mRS, Age, Glucose, Onset-to-treatment, NIHSS) for 3-month outcome after IV thrombolysis-treated ischemic stroke.

LIVE $0.005 USDC GET /api/calc/dragon

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

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

What it computes

Compute the Strbian 2012 DRAGON score (Dense artery / early infarct signs, prestroke mRS, Age, Glucose, Onset-to-treatment, NIHSS) for 3-month outcome after IV thrombolysis-treated ischemic stroke.

When to use

When an agent has caller-assigned admission CT flags, prestroke mRS >1, age, glucose, onset-to-treatment minutes, and NIHSS and needs the published DRAGON total and tabulated 3-month mRS percents, without inventing NIHSS, CT findings, or percents for scores 4-7.

When not to use

Not a medical device and not a tPA, thrombolysis, or reperfusion treatment decision.
Derived in IV thrombolysis-treated anterior-circulation ischemic stroke (Strbian 2012). It was not studied in basilar artery occlusion.
The caller assigns NIHSS (0-42), prestroke modified Rankin Scale >1 as a flag (not a raw mRS integer), (hyper)dense cerebral artery sign, early infarct signs, glucose, and onset-to-treatment time. magent does not examine the patient, read CT, or compute NIHSS.
Published 3-month mRS 0-2 and mRS 5-6 percents are returned only for tabulated scores (0-1, 2, 3, 8, and 9-10). Scores 4-7 have no invented percents.

Formula

DRAGON = dense_ct (hyperdense_artery 1 + early_infarct_signs 1; none 0, either 1, both 2) + prestroke_mrs_gt_1 (1 if prestroke mRS >1) + age (<65 0, 65-79 1, >=80 2) + glucose >8 mmol/L (1; 8.0 does not; mg/dL /18) + onset_to_treatment >90 min (1; 90 does not) + NIHSS (0-4 0, 5-9 1, 10-15 2, >15 3); Strbian 2012; max 10

Citation

Title: Predicting outcome of IV thrombolysis-treated ischemic stroke patients: the DRAGON score
Authors: Strbian D, Meretoja A, Ahlhelm FJ, Pitkäniemi J, Lyrer P, Kaste M, Tatlisumak T
Source: Neurology. 2012;78(6):427-432
DOI: 10.1212/WNL.0b013e318245d2a9

Worked example

Age 60, NIHSS 3, no extras

Given: age=60early_infarct_signs=falseglucose_mmol_l=6.0hyperdense_artery=falsenihss=3onset_to_treatment_min=60prestroke_mrs_gt_1=false

CT none 0; prestroke mRS >1 false 0; age 60 <65 → 0; glucose 6.0 mmol/L ≤8 → 0; onset 60 min ≤90 → 0; NIHSS 3 is 0-4 → 0
Score = 0 (max 10); 3-month mRS 0-2 96%; mRS 5-6 0%

All items maxed

Given: age=80early_infarct_signs=trueglucose_mmol_l=20.0hyperdense_artery=truenihss=42onset_to_treatment_min=360prestroke_mrs_gt_1=true

CT both +2; prestroke mRS >1 +1; age ≥80 +2; glucose 20.0 mmol/L +1; onset 360 min +1; NIHSS 42 +3
Score = 10 (max 10); 3-month mRS 0-2 0%; mRS 5-6 100%

Also searched as

DRAGON score
Strbian DRAGON
dense artery Rankin age glucose onset NIHSS
IV thrombolysis outcome score
3-month mRS DRAGON
Strbian 2012 DRAGON
hyperdense MCA sign DRAGON
prestroke mRS DRAGON

Try

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

/api/calc/dragon?age=60&nihss=3&glucose_mmol_l=6.0&onset_to_treatment_min=60&hyperdense_artery=false&early_infarct_signs=false&prestroke_mrs_gt_1=false

Full URL: https://api.magentlab.com/api/calc/dragon?age=60&nihss=3&glucose_mmol_l=6.0&onset_to_treatment_min=60&hyperdense_artery=false&early_infarct_signs=false&prestroke_mrs_gt_1=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/dragon?age=60&nihss=3&glucose_mmol_l=6.0&onset_to_treatment_min=60&hyperdense_artery=false&early_infarct_signs=false&prestroke_mrs_gt_1=false"

Parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (18-120). Strbian 2012: <65 scores 0; 65-79 scores 1; ≥80 scores 2.
`nihss`	integer	required	Caller-assigned NIH Stroke Scale total (integer 0-42). 0-4 scores 0; 5-9 scores 1; 10-15 scores 2; >15 (16-42) scores 3. magent does not compute NIHSS or examine the patient.
`glucose_mmol_l`	number	optional	Baseline glucose in mmol/L (2.8-55.5). Provide this or glucose_mg_dl, not both. 1 point if >8.0; 8.0 does not score.
`glucose_mg_dl`	number	optional	Baseline glucose in mg/dL (50-1000). Converted as mmol/L = mg/dL / 18. Provide this or glucose_mmol_l, not both. >144 mg/dL scores; 144 does not.
`onset_to_treatment_min`	integer	required	Onset-to-treatment time in minutes (integer 0-360). >90 scores 1; 90 does not. magent does not clock the delay.
`hyperdense_artery`	boolean	required	(Hyper)dense cerebral artery sign on admission CT as assigned by the caller (Strbian 2012). true scores 1. Combined with early_infarct_signs: none 0, either 1, both 2. magent does not read CT.
`early_infarct_signs`	boolean	required	Early infarct signs on admission CT as assigned by the caller (Strbian 2012). true scores 1. Combined with hyperdense_artery: none 0, either 1, both 2. magent does not read CT.
`prestroke_mrs_gt_1`	boolean	required	Prestroke modified Rankin Scale >1 as assigned by the caller (Strbian 2012). true scores 1; false scores 0. Do not send a raw mRS integer. magent does not assign mRS.

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/dragon 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": "60",
      "early_infarct_signs": "false",
      "glucose_mmol_l": "6.0",
      "hyperdense_artery": "false",
      "nihss": "3",
      "onset_to_treatment_min": "60",
      "prestroke_mrs_gt_1": "false"
    },
    {
      "age": "60",
      "early_infarct_signs": "false",
      "glucose_mmol_l": "6.0",
      "hyperdense_artery": "false",
      "nihss": "3",
      "onset_to_treatment_min": "60",
      "prestroke_mrs_gt_1": "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/dragon",
  "items": [
    {
      "components": [
        {
          "factor": "hyperdense_artery",
          "points": 0,
          "present": false
        },
        {
          "factor": "early_infarct_signs",
          "points": 0,
          "present": false
        },
        {
          "factor": "prestroke_mrs_gt_1",
          "points": 0,
          "present": false
        },
        {
          "value": 60,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": 6.0,
          "factor": "glucose",
          "points": 0,
          "present": false
        },
        {
          "value": 60,
          "factor": "onset_to_treatment",
          "points": 0,
          "present": false
        },
        {
          "value": 3,
          "factor": "nihss",
          "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": "Strbian D, Meretoja A, Ahlhelm FJ, Pitkäniemi J, Lyrer P, Kaste M, Tatlisumak T",
        "doi": "10.1212/WNL.0b013e318245d2a9",
        "id": "strbian-2012-dragon",
        "pmid": "22311929",
        "source": "Neurology. 2012;78(6):427-432",
        "title": "Predicting outcome of IV thrombolysis-treated ischemic stroke patients: the DRAGON score"
      },
      "formula": "dragon",
      "formula_expression": "DRAGON = dense_ct (hyperdense_artery 1 + early_infarct_signs 1; none 0, either 1, both 2) + prestroke_mrs_gt_1 (1 if prestroke mRS >1) + age (<65 0, 65-79 1, >=80 2) + glucose >8 mmol/L (1; 8.0 does not; mg/dL /18) + onset_to_treatment >90 min (1; 90 does not) + NIHSS (0-4 0, 5-9 1, 10-15 2, >15 3); Strbian 2012; max 10",
      "age_years": 60,
      "max_score": 10,
      "score": 0,
      "glucose_mmol_l": 6.0,
      "nihss": 3,
      "early_infarct_signs": false,
      "good_outcome_percent": 96,
      "hyperdense_artery": false,
      "miserable_outcome_percent": 0,
      "onset_to_treatment_min": 60,
      "prestroke_mrs_gt_1": false
    },
    {
      "components": [
        {
          "factor": "hyperdense_artery",
          "points": 0,
          "present": false
        },
        {
          "factor": "early_infarct_signs",
          "points": 0,
          "present": false
        },
        {
          "factor": "prestroke_mrs_gt_1",
          "points": 0,
          "present": false
        },
        {
          "value": 60,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": 6.0,
          "factor": "glucose",
          "points": 0,
          "present": false
        },
        {
          "value": 60,
          "factor": "onset_to_treatment",
          "points": 0,
          "present": false
        },
        {
          "value": 3,
          "factor": "nihss",
          "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": "Strbian D, Meretoja A, Ahlhelm FJ, Pitkäniemi J, Lyrer P, Kaste M, Tatlisumak T",
        "doi": "10.1212/WNL.0b013e318245d2a9",
        "id": "strbian-2012-dragon",
        "pmid": "22311929",
        "source": "Neurology. 2012;78(6):427-432",
        "title": "Predicting outcome of IV thrombolysis-treated ischemic stroke patients: the DRAGON score"
      },
      "formula": "dragon",
      "formula_expression": "DRAGON = dense_ct (hyperdense_artery 1 + early_infarct_signs 1; none 0, either 1, both 2) + prestroke_mrs_gt_1 (1 if prestroke mRS >1) + age (<65 0, 65-79 1, >=80 2) + glucose >8 mmol/L (1; 8.0 does not; mg/dL /18) + onset_to_treatment >90 min (1; 90 does not) + NIHSS (0-4 0, 5-9 1, 10-15 2, >15 3); Strbian 2012; max 10",
      "age_years": 60,
      "max_score": 10,
      "score": 0,
      "glucose_mmol_l": 6.0,
      "nihss": 3,
      "early_infarct_signs": false,
      "good_outcome_percent": 96,
      "hyperdense_artery": false,
      "miserable_outcome_percent": 0,
      "onset_to_treatment_min": 60,
      "prestroke_mrs_gt_1": false
    }
  ]
}

Response

Field	Type	Description
`formula`	string	dragon
`formula_expression`	string	Exact expression used
`score`	integer	DRAGON points 0-10
`max_score`	integer	Always 10
`good_outcome_percent`	number	Published 3-month mRS 0-2 percent when tabulated (0-1, 2, 3, 8-10); null for scores 4-7
`miserable_outcome_percent`	number	Published 3-month mRS 5-6 percent when tabulated (0-1, 2, 3, 8, 9-10); null for scores 4-7
`age_years`	integer	Age used for trichotomized age points
`nihss`	integer	Caller-assigned NIHSS used for points
`glucose_mmol_l`	number	Baseline glucose in mmol/L (mg/dL inputs converted /18)
`onset_to_treatment_min`	integer	Onset-to-treatment minutes used for the >90 item
`hyperdense_artery`	boolean	Whether (hyper)dense cerebral artery sign was scored
`early_infarct_signs`	boolean	Whether early infarct signs were scored
`prestroke_mrs_gt_1`	boolean	Whether prestroke mRS >1 was scored
`components`	array	Per-item Strbian 2012 points
`citation`	object	Strbian 2012 Neurology citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "hyperdense_artery",
      "points": 0,
      "present": false
    },
    {
      "factor": "early_infarct_signs",
      "points": 0,
      "present": false
    },
    {
      "factor": "prestroke_mrs_gt_1",
      "points": 0,
      "present": false
    },
    {
      "value": 60,
      "factor": "age",
      "points": 0,
      "present": false
    },
    {
      "value": 6.0,
      "factor": "glucose",
      "points": 0,
      "present": false
    },
    {
      "value": 60,
      "factor": "onset_to_treatment",
      "points": 0,
      "present": false
    },
    {
      "value": 3,
      "factor": "nihss",
      "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": "Strbian D, Meretoja A, Ahlhelm FJ, Pitkäniemi J, Lyrer P, Kaste M, Tatlisumak T",
    "doi": "10.1212/WNL.0b013e318245d2a9",
    "id": "strbian-2012-dragon",
    "pmid": "22311929",
    "source": "Neurology. 2012;78(6):427-432",
    "title": "Predicting outcome of IV thrombolysis-treated ischemic stroke patients: the DRAGON score"
  },
  "formula": "dragon",
  "formula_expression": "DRAGON = dense_ct (hyperdense_artery 1 + early_infarct_signs 1; none 0, either 1, both 2) + prestroke_mrs_gt_1 (1 if prestroke mRS >1) + age (<65 0, 65-79 1, >=80 2) + glucose >8 mmol/L (1; 8.0 does not; mg/dL /18) + onset_to_treatment >90 min (1; 90 does not) + NIHSS (0-4 0, 5-9 1, 10-15 2, >15 3); Strbian 2012; max 10",
  "age_years": 60,
  "max_score": 10,
  "score": 0,
  "glucose_mmol_l": 6.0,
  "nihss": 3,
  "early_infarct_signs": false,
  "good_outcome_percent": 96,
  "hyperdense_artery": false,
  "miserable_outcome_percent": 0,
  "onset_to_treatment_min": 60,
  "prestroke_mrs_gt_1": false
}

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_nihss`	nihss must be an integer from 0 to 42. Returned before settlement; you are not charged.
400	`invalid_glucose`	glucose_mg_dl (50-1000) or glucose_mmol_l (2.8-55.5) is required Returned before settlement; you are not charged.
400	`invalid_onset_to_treatment_min`	onset_to_treatment_min must be an integer from 0 to 360. 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

THRIVE — Compute the Flint 2010 THRIVE (Totaled Health Risks in Vascular Events) score from trichotomized age, trichotomized NIHSS, and the chronic disease scale (hypertension, diabetes mellitus, atrial fibrillation).
ASTRAL — Compute the Ntaios 2012 ASTRAL integer score (Age, Severity NIHSS, Time delay, Range of visual fields, Acute glucose, Level of consciousness) for 3-month mRS >2 after acute ischemic stroke.

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.