# CURB-65

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/curb65`
HTML: https://magentlab.com/docs/curb65
Markdown: https://magentlab.com/docs/curb65.md

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

## What it computes

Compute the CURB-65 community-acquired pneumonia severity score from age and discrete flags.

## When to use

When an agent needs the published CURB-65 total and must not invent points from a chart narrative.

## When not to use

- Not a treatment recommendation and not a site-of-care decision.
- urea_high is a boolean flag. magent does not convert BUN mg/dL to urea mmol/L.

## Formula

```
CURB-65 = confusion + urea_high + respiratory_rate_ge_30 + low_blood_pressure + age_ge_65; max 5
```

## Citation

Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study
Lim WS, van der Eerden MM, Laing R, et al.
Thorax. 2003;58(5):377-382
DOI: [10.1136/thorax.58.5.377](https://doi.org/10.1136/thorax.58.5.377)

## Worked example

### Age 70, confusion, urea high

Given: `age=70, confusion=true, low_blood_pressure=false, respiratory_rate_ge_30=false, urea_high=true`

1. Confusion → 1; urea_high → 1; age ≥65 → 1
2. Score = 3


## Parameters

- `age` (integer, required): Age in years (18-120). Age ≥65 scores 1.
- `confusion` (boolean, required): New confusion (C). true or false.
- `urea_high` (boolean, required): Urea >7 mmol/L (U). Pass the published cutoff as a flag; magent does not convert BUN.
- `respiratory_rate_ge_30` (boolean, required): Respiratory rate ≥30/min (R). true or false.
- `low_blood_pressure` (boolean, required): SBP <90 mmHg or DBP ≤60 mmHg (B). true or false.

## Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/curb65`
Max items: 25
Price: unit_amount * n (unit 5000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- 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. HTML paywall is GET only.

Example request:

```json
{
  "items": [
    {
      "age": "70",
      "confusion": "true",
      "low_blood_pressure": "false",
      "respiratory_rate_ge_30": "false",
      "urea_high": "true"
    },
    {
      "age": "70",
      "confusion": "true",
      "low_blood_pressure": "false",
      "respiratory_rate_ge_30": "false",
      "urea_high": "true"
    }
  ]
}
```

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/curb65",
  "items": [
    {
      "components": [
        {
          "factor": "confusion",
          "points": 1,
          "present": true
        },
        {
          "factor": "urea_high",
          "points": 1,
          "present": true
        },
        {
          "factor": "respiratory_rate_ge_30",
          "points": 0,
          "present": false
        },
        {
          "factor": "low_blood_pressure",
          "points": 0,
          "present": false
        },
        {
          "value": 70,
          "factor": "age_ge_65",
          "points": 1,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 70,
      "citation": {
        "authors": "Lim WS, van der Eerden MM, Laing R, et al.",
        "doi": "10.1136/thorax.58.5.377",
        "id": "lim-2003",
        "source": "Thorax. 2003;58(5):377-382",
        "title": "Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study"
      },
      "formula": "curb65",
      "formula_expression": "CURB-65 = confusion + urea_high + respiratory_rate_ge_30 + low_blood_pressure + age_ge_65; max 5",
      "max_score": 5,
      "score": 3
    },
    {
      "components": [
        {
          "factor": "confusion",
          "points": 1,
          "present": true
        },
        {
          "factor": "urea_high",
          "points": 1,
          "present": true
        },
        {
          "factor": "respiratory_rate_ge_30",
          "points": 0,
          "present": false
        },
        {
          "factor": "low_blood_pressure",
          "points": 0,
          "present": false
        },
        {
          "value": 70,
          "factor": "age_ge_65",
          "points": 1,
          "present": true
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "age_years": 70,
      "citation": {
        "authors": "Lim WS, van der Eerden MM, Laing R, et al.",
        "doi": "10.1136/thorax.58.5.377",
        "id": "lim-2003",
        "source": "Thorax. 2003;58(5):377-382",
        "title": "Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study"
      },
      "formula": "curb65",
      "formula_expression": "CURB-65 = confusion + urea_high + respiratory_rate_ge_30 + low_blood_pressure + age_ge_65; max 5",
      "max_score": 5,
      "score": 3
    }
  ]
}
```

## Response fields

- `formula` (string): curb65
- `formula_expression` (string): Exact expression used
- `score` (integer): Total points 0-5
- `max_score` (integer): Always 5
- `age_years` (integer): Age used for the 65 criterion
- `components` (array): Per-factor points
- `citation` (object): Thorax 2003 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "factor": "confusion",
      "points": 1,
      "present": true
    },
    {
      "factor": "urea_high",
      "points": 1,
      "present": true
    },
    {
      "factor": "respiratory_rate_ge_30",
      "points": 0,
      "present": false
    },
    {
      "factor": "low_blood_pressure",
      "points": 0,
      "present": false
    },
    {
      "value": 70,
      "factor": "age_ge_65",
      "points": 1,
      "present": true
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "age_years": 70,
  "citation": {
    "authors": "Lim WS, van der Eerden MM, Laing R, et al.",
    "doi": "10.1136/thorax.58.5.377",
    "id": "lim-2003",
    "source": "Thorax. 2003;58(5):377-382",
    "title": "Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study"
  },
  "formula": "curb65",
  "formula_expression": "CURB-65 = confusion + urea_high + respiratory_rate_ge_30 + low_blood_pressure + age_ge_65; max 5",
  "max_score": 5,
  "score": 3
}
```

## Errors

- HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged.
- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.
- HTTP 402 `payment_required`: Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
- HTTP 409 `payment_in_progress`: The same authorization nonce is already being settled; retry shortly
- HTTP 429 `rate_limited`: Too many requests from this client
- HTTP 503 `settlement_uncertain`: Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
- HTTP 503 `facilitator_unavailable`: Payment facilitator unavailable
- HTTP 503 `facilitator_misconfigured`: Payment facilitator is not configured
- HTTP 503 `facilitator_unauthorized`: Payment facilitator rejected credentials
- HTTP 503 `ledger_unavailable`: Payment ledger unavailable
- HTTP 503 `payment_unavailable`: Payment processing unavailable

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- [Wells DVT](https://magentlab.com/docs/wells-dvt) — Compute the Wells deep-vein thrombosis probability score and return three-tier and two-tier bands.

## Also searched as

- CURB 65
- CURB65 score
- Lim pneumonia score
- CAP severity

## Payment

Required query parameters must be present and valid. 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.

## Guarantees

- Invalid query parameters return HTTP 400 before settlement. You are not charged.
- Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are not persisted. Request logs store path without query.