Emergency · LIVE

CSHA Clinical Frailty Scale (Rockwood 2005)

CFS

Return the Rockwood 2005 CSHA Clinical Frailty Scale 1-7 from a caller-assigned integer, with the published Box 1 description.

LIVE $0.005 USDC GET /api/calc/cfs

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

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

What it computes

Return the Rockwood 2005 CSHA Clinical Frailty Scale 1-7 from a caller-assigned integer, with the published Box 1 description.

When to use

When an agent already has a CSHA Clinical Frailty Scale 1-7 as in Rockwood 2005 Box 1 and must not invent the later 9-point CFS or CFS 2.0 labels.

When not to use

• Not a medical device and not a diagnosis. magent does not examine the patient.
• Rockwood 2005 7-point CSHA Clinical Frailty Scale only. magent does not implement the later 9-point CFS (8 very severely frail, 9 terminally ill) or CFS 2.0 label changes.
• The caller assigns cfs 1-7. magent does not interview or examine the patient.

Formula

CSHA Clinical Frailty Scale 1-7 as assigned by the caller (Rockwood 2005 Box 1); not the later 9-point CFS

Citation

Title

A global clinical measure of fitness and frailty in elderly people

Authors

Rockwood K, Song X, MacKnight C, Bergman H, Hogan DB, McDowell I, Mitnitski A

Source

CMAJ. 2005;173(5):489-495

DOI

10.1503/cmaj.050051

Worked example

Also searched as

• clinical frailty scale
• CSHA CFS
• Rockwood frailty
• Clinical Frailty Scale
• Rockwood CFS
• CSHA Clinical Frailty Scale
• frailty scale
• Rockwood 2005

Try

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

/api/calc/cfs?cfs=1

Full URL: https://api.magentlab.com/api/calc/cfs?cfs=1

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/cfs?cfs=1"

Parameters

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/cfs 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": [
    {
      "cfs": "1"
    },
    {
      "cfs": "1"
    }
  ]
}

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/cfs",
  "items": [
    {
      "description": "Very fit — robust, active, energetic, well motivated and fit; these people commonly exercise regularly and are in the most fit group for their age",
      "components": [
        {
          "factor": "cfs",
          "points": 1,
          "present": true
        }
      ],
      "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": "Rockwood K, Song X, MacKnight C, Bergman H, Hogan DB, McDowell I, Mitnitski A",
        "doi": "10.1503/cmaj.050051",
        "id": "rockwood-2005",
        "pmid": "16129869",
        "source": "CMAJ. 2005;173(5):489-495",
        "title": "A global clinical measure of fitness and frailty in elderly people"
      },
      "formula": "cfs",
      "formula_expression": "CSHA Clinical Frailty Scale 1-7 as assigned by the caller (Rockwood 2005 Box 1); not the later 9-point CFS",
      "max_score": 7,
      "score": 1,
      "cfs": 1
    },
    {
      "description": "Very fit — robust, active, energetic, well motivated and fit; these people commonly exercise regularly and are in the most fit group for their age",
      "components": [
        {
          "factor": "cfs",
          "points": 1,
          "present": true
        }
      ],
      "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": "Rockwood K, Song X, MacKnight C, Bergman H, Hogan DB, McDowell I, Mitnitski A",
        "doi": "10.1503/cmaj.050051",
        "id": "rockwood-2005",
        "pmid": "16129869",
        "source": "CMAJ. 2005;173(5):489-495",
        "title": "A global clinical measure of fitness and frailty in elderly people"
      },
      "formula": "cfs",
      "formula_expression": "CSHA Clinical Frailty Scale 1-7 as assigned by the caller (Rockwood 2005 Box 1); not the later 9-point CFS",
      "max_score": 7,
      "score": 1,
      "cfs": 1
    }
  ]
}

Response

Example JSON

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

{
  "description": "Very fit — robust, active, energetic, well motivated and fit; these people commonly exercise regularly and are in the most fit group for their age",
  "components": [
    {
      "factor": "cfs",
      "points": 1,
      "present": true
    }
  ],
  "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": "Rockwood K, Song X, MacKnight C, Bergman H, Hogan DB, McDowell I, Mitnitski A",
    "doi": "10.1503/cmaj.050051",
    "id": "rockwood-2005",
    "pmid": "16129869",
    "source": "CMAJ. 2005;173(5):489-495",
    "title": "A global clinical measure of fitness and frailty in elderly people"
  },
  "formula": "cfs",
  "formula_expression": "CSHA Clinical Frailty Scale 1-7 as assigned by the caller (Rockwood 2005 Box 1); not the later 9-point CFS",
  "max_score": 7,
  "score": 1,
  "cfs": 1
}

Client errors (HTTP 400)

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

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• Braden Scale — Sum six caller-assigned Bergstrom 1987 Braden Scale subscale points and return at_risk when the total is ≤16.

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.