Infection / VTE · LIVE

Centor and McIsaac scores

Compute the Centor score or the McIsaac age-modified score from four caller-assigned pharyngitis findings. The edition is required.

LIVE $0.005 USDC GET /api/calc/centor

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

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

What it computes

Compute the Centor score or the McIsaac age-modified score from four caller-assigned pharyngitis findings. The edition is required.

When to use

When an agent needs a published Centor or McIsaac total and must not silently pick an edition or invent the four clinical findings.

When not to use

Not a test-or-treat protocol and not a diagnosis of streptococcal pharyngitis.
The caller assigns the four clinical findings. magent does not examine the throat.
McIsaac age bands are 3-14 / 15-44 / >=45 as published. edition is required; magent does not pick Centor or McIsaac.

Formula

McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5

Citation

Title: Empirical validation of guidelines for the management of pharyngitis in children and adults
Authors: McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE
Source: JAMA. 2004;291(13):1587-1595
DOI: 10.1001/jama.291.13.1587

Worked example

McIsaac adult all-negative

Given: age=30cough_absent=falseedition=mcisaachistory_of_fever=falsetender_anterior_cervical_nodes=falsetonsillar_exudates=false

Four findings absent; age 30 is 15-44 → 0
Score = 0 (max 5)

Centor all four present

Given: cough_absent=trueedition=centorhistory_of_fever=truetender_anterior_cervical_nodes=truetonsillar_exudates=true

Four findings present → 1 each
Score = 4 (max 4)

McIsaac child all-negative

Given: age=8cough_absent=falseedition=mcisaachistory_of_fever=falsetender_anterior_cervical_nodes=falsetonsillar_exudates=false

Four findings absent; age 8 is 3-14 → +1
Score = 1

Also searched as

Centor score
McIsaac score
modified Centor score
strep pharyngitis score
streptococcal pharyngitis criteria
tonsillar exudates tender nodes

Try

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

/api/calc/centor?edition=mcisaac&age=30&tonsillar_exudates=false&tender_anterior_cervical_nodes=false&history_of_fever=false&cough_absent=false

Full URL: https://api.magentlab.com/api/calc/centor?edition=mcisaac&age=30&tonsillar_exudates=false&tender_anterior_cervical_nodes=false&history_of_fever=false&cough_absent=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/centor?edition=mcisaac&age=30&tonsillar_exudates=false&tender_anterior_cervical_nodes=false&history_of_fever=false&cough_absent=false"

Parameters

Name	Type	Required	Description
`edition`	string	required · centor, mcisaac	Published score. Required; magent does not pick Centor (four findings, max 4) or McIsaac (age-modified, max 5).
`age`	integer	optional	Age in years (3-120). Required when edition=mcisaac (3-14 +1, 15-44 0, >=45 -1). Ignored when edition=centor.
`tonsillar_exudates`	boolean	required	Tonsillar exudates. true or false as assigned by the caller.
`tender_anterior_cervical_nodes`	boolean	required	Tender anterior cervical nodes. true or false as assigned by the caller.
`history_of_fever`	boolean	required	History of fever. true or false as assigned by the caller.
`cough_absent`	boolean	required	Absence of cough. true when cough is absent; false when cough is present.

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/centor 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": "30",
      "cough_absent": "false",
      "edition": "mcisaac",
      "history_of_fever": "false",
      "tender_anterior_cervical_nodes": "false",
      "tonsillar_exudates": "false"
    },
    {
      "age": "30",
      "cough_absent": "false",
      "edition": "mcisaac",
      "history_of_fever": "false",
      "tender_anterior_cervical_nodes": "false",
      "tonsillar_exudates": "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/centor",
  "items": [
    {
      "components": [
        {
          "factor": "tonsillar_exudates",
          "points": 0,
          "present": false
        },
        {
          "factor": "tender_anterior_cervical_nodes",
          "points": 0,
          "present": false
        },
        {
          "factor": "history_of_fever",
          "points": 0,
          "present": false
        },
        {
          "factor": "cough_absent",
          "points": 0,
          "present": false
        },
        {
          "value": 30,
          "factor": "age_adjustment",
          "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": 30,
      "citation": {
        "authors": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE",
        "doi": "10.1001/jama.291.13.1587",
        "id": "mcisaac-2004",
        "source": "JAMA. 2004;291(13):1587-1595",
        "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults"
      },
      "formula": "mcisaac",
      "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5",
      "max_score": 5,
      "score": 0,
      "edition": "mcisaac"
    },
    {
      "components": [
        {
          "factor": "tonsillar_exudates",
          "points": 0,
          "present": false
        },
        {
          "factor": "tender_anterior_cervical_nodes",
          "points": 0,
          "present": false
        },
        {
          "factor": "history_of_fever",
          "points": 0,
          "present": false
        },
        {
          "factor": "cough_absent",
          "points": 0,
          "present": false
        },
        {
          "value": 30,
          "factor": "age_adjustment",
          "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": 30,
      "citation": {
        "authors": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE",
        "doi": "10.1001/jama.291.13.1587",
        "id": "mcisaac-2004",
        "source": "JAMA. 2004;291(13):1587-1595",
        "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults"
      },
      "formula": "mcisaac",
      "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5",
      "max_score": 5,
      "score": 0,
      "edition": "mcisaac"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	centor or mcisaac
`formula_expression`	string	Exact expression used
`edition`	string	centor or mcisaac
`score`	integer	Total points (0-4 Centor; -1 to 5 McIsaac)
`max_score`	integer	4 (Centor) or 5 (McIsaac)
`age_years`	integer	Age used for McIsaac bands. Present when edition=mcisaac.
`components`	array	Per-finding points
`citation`	object	Centor 1981 or McIsaac 2004
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "tonsillar_exudates",
      "points": 0,
      "present": false
    },
    {
      "factor": "tender_anterior_cervical_nodes",
      "points": 0,
      "present": false
    },
    {
      "factor": "history_of_fever",
      "points": 0,
      "present": false
    },
    {
      "factor": "cough_absent",
      "points": 0,
      "present": false
    },
    {
      "value": 30,
      "factor": "age_adjustment",
      "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": 30,
  "citation": {
    "authors": "McIsaac WJ, Kellner JD, Aufricht P, Vanjaka A, Low DE",
    "doi": "10.1001/jama.291.13.1587",
    "id": "mcisaac-2004",
    "source": "JAMA. 2004;291(13):1587-1595",
    "title": "Empirical validation of guidelines for the management of pharyngitis in children and adults"
  },
  "formula": "mcisaac",
  "formula_expression": "McIsaac = Centor criteria + age 3-14 +1, 15-44 0, >=45 -1; max 5",
  "max_score": 5,
  "score": 0,
  "edition": "mcisaac"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_centor_edition`	edition must be centor or mcisaac. 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_centor_age`	age must be an integer from 3 to 120 (McIsaac). 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

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.