Neurology · LIVE

Neck Disability Index

NDI

Sum ten caller-assigned Vernon 1991 Neck Disability Index sections (each integer 0-5) and return the published 0-50 total with that paper's raw-score disability bands.

LIVE $0.005 USDC GET /api/calc/ndi

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

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

What it computes

Sum ten caller-assigned Vernon 1991 Neck Disability Index sections (each integer 0-5) and return the published 0-50 total with that paper's raw-score disability bands.

When to use

When an agent already has Vernon 1991 integers 0-5 for the ten NDI sections and needs the published total and raw 0-50 bands. magent does not interview the patient, diagnose neck disease, score Oswestry, or apply later percentage website cutoffs.

When not to use

• Not a medical device and not a diagnosis of neck pathology or a treatment order.
• Each of the ten sections is a caller-assigned integer 0-5. magent does not interview the patient.
• Vernon 1991 scored the raw 0-50 total. Bands are 0-4 none, 5-14 mild, 15-24 moderate, 25-34 severe, and >34 complete. magent does not convert to a 0-100 percent or apply later 0-8%/10-28% website percentage bands.
• This is Vernon 1991 NDI only. magent does not score the Oswestry Low Back Pain Disability Questionnaire.

Formula

NDI = pain_intensity + personal_care + lifting + reading + headaches + concentration + work + driving + sleeping + recreation; each caller-assigned 0-5; Vernon 1991 ten sections; max 50; raw 0-50 bands 0-4 none, 5-14 mild, 15-24 moderate, 25-34 severe, >34 complete

Citation

Title

The Neck Disability Index: a study of reliability and validity

Authors

Vernon H, Mior S

Source

J Manipulative Physiol Ther. 1991;14(7):409-415

DOI

none

Worked example

Also searched as

• NDI
• Neck Disability Index
• Vernon NDI
• neck pain disability
• NDI score
• Vernon 1991 NDI
• cervical disability index
• neck disability questionnaire
• NDI 0-50

Try

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

/api/calc/ndi?pain_intensity=0&personal_care=0&lifting=0&reading=0&headaches=0&concentration=0&work=0&driving=0&sleeping=0&recreation=0

Full URL: https://api.magentlab.com/api/calc/ndi?pain_intensity=0&personal_care=0&lifting=0&reading=0&headaches=0&concentration=0&work=0&driving=0&sleeping=0&recreation=0

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/ndi?pain_intensity=0&personal_care=0&lifting=0&reading=0&headaches=0&concentration=0&work=0&driving=0&sleeping=0&recreation=0"

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/ndi 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": [
    {
      "concentration": "0",
      "driving": "0",
      "headaches": "0",
      "lifting": "0",
      "pain_intensity": "0",
      "personal_care": "0",
      "reading": "0",
      "recreation": "0",
      "sleeping": "0",
      "work": "0"
    },
    {
      "concentration": "0",
      "driving": "0",
      "headaches": "0",
      "lifting": "0",
      "pain_intensity": "0",
      "personal_care": "0",
      "reading": "0",
      "recreation": "0",
      "sleeping": "0",
      "work": "0"
    }
  ]
}

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/ndi",
  "items": [
    {
      "components": [
        {
          "value": 0,
          "factor": "pain_intensity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "personal_care",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lifting",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "reading",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "headaches",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "work",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "driving",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleeping",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "recreation",
          "points": 0,
          "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": "Vernon H, Mior S",
        "id": "vernon-1991",
        "pmid": "1834753",
        "source": "J Manipulative Physiol Ther. 1991;14(7):409-415",
        "title": "The Neck Disability Index: a study of reliability and validity"
      },
      "formula": "ndi",
      "formula_expression": "NDI = pain_intensity + personal_care + lifting + reading + headaches + concentration + work + driving + sleeping + recreation; each caller-assigned 0-5; Vernon 1991 ten sections; max 50; raw 0-50 bands 0-4 none, 5-14 mild, 15-24 moderate, 25-34 severe, >34 complete",
      "max_score": 50,
      "score": 0,
      "disability": "none"
    },
    {
      "components": [
        {
          "value": 0,
          "factor": "pain_intensity",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "personal_care",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "lifting",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "reading",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "headaches",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "concentration",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "work",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "driving",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "sleeping",
          "points": 0,
          "present": true
        },
        {
          "value": 0,
          "factor": "recreation",
          "points": 0,
          "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": "Vernon H, Mior S",
        "id": "vernon-1991",
        "pmid": "1834753",
        "source": "J Manipulative Physiol Ther. 1991;14(7):409-415",
        "title": "The Neck Disability Index: a study of reliability and validity"
      },
      "formula": "ndi",
      "formula_expression": "NDI = pain_intensity + personal_care + lifting + reading + headaches + concentration + work + driving + sleeping + recreation; each caller-assigned 0-5; Vernon 1991 ten sections; max 50; raw 0-50 bands 0-4 none, 5-14 mild, 15-24 moderate, 25-34 severe, >34 complete",
      "max_score": 50,
      "score": 0,
      "disability": "none"
    }
  ]
}

Response

Example JSON

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

{
  "components": [
    {
      "value": 0,
      "factor": "pain_intensity",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "personal_care",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "lifting",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "reading",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "headaches",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "concentration",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "work",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "driving",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "sleeping",
      "points": 0,
      "present": true
    },
    {
      "value": 0,
      "factor": "recreation",
      "points": 0,
      "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": "Vernon H, Mior S",
    "id": "vernon-1991",
    "pmid": "1834753",
    "source": "J Manipulative Physiol Ther. 1991;14(7):409-415",
    "title": "The Neck Disability Index: a study of reliability and validity"
  },
  "formula": "ndi",
  "formula_expression": "NDI = pain_intensity + personal_care + lifting + reading + headaches + concentration + work + driving + sleeping + recreation; each caller-assigned 0-5; Vernon 1991 ten sections; max 50; raw 0-50 bands 0-4 none, 5-14 mild, 15-24 moderate, 25-34 severe, >34 complete",
  "max_score": 50,
  "score": 0,
  "disability": "none"
}

Client errors (HTTP 400)

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

Related tools

• Barthel Index — Sum ten caller-assigned Mahoney 1965 Barthel Index item points and return the published 0-100 total.
• Modified Rankin — Return the van Swieten 1988 modified Rankin handicap grade 0-5 from a caller-assigned integer, with the published grade wording.

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.