# Newsom CXR rule

Newsom CXR rule

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

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

## What it computes

Apply the Newsom 2014 modified Rothrock rule and return whether a chest radiograph is indicated from caller-assigned age and five history or exam flags.

## When to use

When an agent has caller-assigned findings for an adult with nontraumatic chest pain in the emergency department and needs the published 2014 modified Rothrock CXR-indicated result. magent does not examine the patient or read a radiograph. Not the original Rothrock 2002 rule and not the 2018 prospective refinement.

## When not to use

- Not a medical device. Not a diagnosis. magent does not examine the patient or read a radiograph.
- This tool is the Newsom 2014 modified Rothrock rule only. It does not include hypoxia, rales, hemoptysis, history of tuberculosis, or thromboembolic disease (removed in the 2014 modification). It is not the original Rothrock 2002 ten-item rule and not the 2018 Academic Emergency Medicine prospective refinement.
- Age is an integer 18-120; the age criterion is met at 65 or older. CHF, alcohol abuse, decreased breath sounds, fever, and tachypnea are caller-assigned booleans. magent does not measure temperature or respiratory rate or auscultate the chest.
- Presence of a criterion does not order a chest radiograph. A negative rule does not exclude all clinically significant radiographic findings.

## Formula

```
CXR indicated iff age >= 65 or congestive heart failure or alcohol abuse or decreased breath sounds or fever or tachypnea (Newsom 2014 modified Rothrock; not hypoxia, rales, hemoptysis, TB, or thromboembolic disease; not the 2018 Academic Emergency Medicine prospective refinement)
```

## Citation

[Validation of a Decision Rule and Derivation of a Modified Rule to Obtain Chest Radiograph in Patients with Nontraumatic Chest Pain in the Emergency Department](https://doi.org/10.1155/2014/241935)
Newsom C, Jeanmonod R, Weller K, Boutros N, Reiter M, Jeanmonod D
Adv Emerg Med. 2014;2014:241935
DOI: [10.1155/2014/241935](https://doi.org/10.1155/2014/241935)

## Worked example

### Age 40, all flags false

Given: `age=40, alcohol_abuse=false, chf=false, decreased_breath_sounds=false, fever=false, tachypnea=false`

1. Age 40 is not ≥ 65
2. CHF, alcohol abuse, decreased breath sounds, fever, and tachypnea are absent
3. CXR is not indicated


### Age 65 only

Given: `age=65, alcohol_abuse=false, chf=false, decreased_breath_sounds=false, fever=false, tachypnea=false`

1. Age 65 meets the ≥ 65 criterion
2. All five history and exam flags are false
3. CXR is indicated


## Also searched as

- Newsom CXR rule
- modified Rothrock CXR
- Newsom 2014 chest radiograph
- nontraumatic chest pain CXR rule
- Newsom modified Rothrock
- chest x-ray decision rule chest pain
- Newsom chest radiograph rule

## Parameters

- `age` (integer, required): Age in years (integer 18-120). The Newsom 2014 age criterion is met at 65 or older; 64 does not meet.
- `chf` (boolean, required): History of congestive heart failure as assigned by the caller. true or false. true means the Newsom 2014 CXR criterion is met. magent does not diagnose heart failure.
- `alcohol_abuse` (boolean, required): History of alcohol abuse as assigned by the caller. true or false. true means the Newsom 2014 CXR criterion is met.
- `decreased_breath_sounds` (boolean, required): Decreased breath sounds on exam as assigned by the caller. true or false. true means the Newsom 2014 CXR criterion is met. magent does not auscultate the chest.
- `fever` (boolean, required): Fever as assigned by the caller (paper: temperature greater than 100.4 F). true or false. true means the Newsom 2014 CXR criterion is met. magent does not measure temperature.
- `tachypnea` (boolean, required): Tachypnea as assigned by the caller (original Rothrock: respiratory rate greater than 24 breaths/min; retained as tachypnea in the 2014 modification). true or false. true means the Newsom 2014 CXR criterion is met. magent does not measure respiratory rate.

## 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.

Method: `POST /api/calc/newsom`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: 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:

```json
{
  "items": [
    {
      "age": "40",
      "alcohol_abuse": "false",
      "chf": "false",
      "decreased_breath_sounds": "false",
      "fever": "false",
      "tachypnea": "false"
    },
    {
      "age": "40",
      "alcohol_abuse": "false",
      "chf": "false",
      "decreased_breath_sounds": "false",
      "fever": "false",
      "tachypnea": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/newsom

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/newsom",
  "items": [
    {
      "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": "Newsom C, Jeanmonod R, Weller K, Boutros N, Reiter M, Jeanmonod D",
        "doi": "10.1155/2014/241935",
        "id": "newsom-2014",
        "source": "Adv Emerg Med. 2014;2014:241935",
        "title": "Validation of a Decision Rule and Derivation of a Modified Rule to Obtain Chest Radiograph in Patients with Nontraumatic Chest Pain in the Emergency Department"
      },
      "formula": "newsom",
      "formula_expression": "CXR indicated iff age >= 65 or congestive heart failure or alcohol abuse or decreased breath sounds or fever or tachypnea (Newsom 2014 modified Rothrock; not hypoxia, rales, hemoptysis, TB, or thromboembolic disease; not the 2018 Academic Emergency Medicine prospective refinement)",
      "criteria": [
        {
          "value": 40,
          "factor": "age_ge_65",
          "met": false
        },
        {
          "factor": "chf",
          "met": false
        },
        {
          "factor": "alcohol_abuse",
          "met": false
        },
        {
          "factor": "decreased_breath_sounds",
          "met": false
        },
        {
          "factor": "fever",
          "met": false
        },
        {
          "factor": "tachypnea",
          "met": false
        }
      ],
      "cxr_indicated": 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": "Newsom C, Jeanmonod R, Weller K, Boutros N, Reiter M, Jeanmonod D",
        "doi": "10.1155/2014/241935",
        "id": "newsom-2014",
        "source": "Adv Emerg Med. 2014;2014:241935",
        "title": "Validation of a Decision Rule and Derivation of a Modified Rule to Obtain Chest Radiograph in Patients with Nontraumatic Chest Pain in the Emergency Department"
      },
      "formula": "newsom",
      "formula_expression": "CXR indicated iff age >= 65 or congestive heart failure or alcohol abuse or decreased breath sounds or fever or tachypnea (Newsom 2014 modified Rothrock; not hypoxia, rales, hemoptysis, TB, or thromboembolic disease; not the 2018 Academic Emergency Medicine prospective refinement)",
      "criteria": [
        {
          "value": 40,
          "factor": "age_ge_65",
          "met": false
        },
        {
          "factor": "chf",
          "met": false
        },
        {
          "factor": "alcohol_abuse",
          "met": false
        },
        {
          "factor": "decreased_breath_sounds",
          "met": false
        },
        {
          "factor": "fever",
          "met": false
        },
        {
          "factor": "tachypnea",
          "met": false
        }
      ],
      "cxr_indicated": false
    }
  ]
}
```

## Response fields

- `formula` (string): newsom
- `formula_expression` (string): Newsom 2014 modified Rothrock six-factor any-present rule
- `cxr_indicated` (boolean): true when any of the six Newsom 2014 modified factors is present. Does not order a chest radiograph. Not a diagnosis.
- `criteria` (array): Per-factor rows with factor, met, and age value; met is true when that Newsom 2014 factor is present
- `citation` (object): Newsom 2014 Adv Emerg Med citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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": "Newsom C, Jeanmonod R, Weller K, Boutros N, Reiter M, Jeanmonod D",
    "doi": "10.1155/2014/241935",
    "id": "newsom-2014",
    "source": "Adv Emerg Med. 2014;2014:241935",
    "title": "Validation of a Decision Rule and Derivation of a Modified Rule to Obtain Chest Radiograph in Patients with Nontraumatic Chest Pain in the Emergency Department"
  },
  "formula": "newsom",
  "formula_expression": "CXR indicated iff age >= 65 or congestive heart failure or alcohol abuse or decreased breath sounds or fever or tachypnea (Newsom 2014 modified Rothrock; not hypoxia, rales, hemoptysis, TB, or thromboembolic disease; not the 2018 Academic Emergency Medicine prospective refinement)",
  "criteria": [
    {
      "value": 40,
      "factor": "age_ge_65",
      "met": false
    },
    {
      "factor": "chf",
      "met": false
    },
    {
      "factor": "alcohol_abuse",
      "met": false
    },
    {
      "factor": "decreased_breath_sounds",
      "met": false
    },
    {
      "factor": "fever",
      "met": false
    },
    {
      "factor": "tachypnea",
      "met": false
    }
  ],
  "cxr_indicated": false
}
```

## Errors

- HTTP 400 `invalid_newsom`: Newsom CXR-rule inputs must be the six caller-assigned 2014 modified flags (age 65 or older, CHF, alcohol abuse, decreased breath sounds, fever, tachypnea). 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.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [HEAR score](https://magentlab.com/docs/hear) — Compute the HEAR score as age points plus caller-assigned history, ECG, and risk factors (each 0-2). No troponin.
- [Vancouver Chest Pain Rule](https://magentlab.com/docs/vancouver-chest-pain) — Apply the Christenson 2006 Vancouver Chest Pain Rule derivation tree and return whether caller-assigned ECG, 2-hour troponin, prior ACS or nitrate, palpation, age, and radiation nodes are early-discharge eligible.

## 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.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/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.