Modified Hoehn and Yahr Stage (Goetz 2004)

Modified Hoehn and Yahr

Echo the caller-assigned Goetz 2004 Table 1 modified Hoehn and Yahr stage (1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0) with the published description. No stage 0. magent does not examine the patient.

LIVE $0.005 USDC GET /api/calc/modified_hoehn_yahr

Markdown: /docs/modified-hoehn-yahr.md · Canonical: https://magentlab.com/docs/modified-hoehn-yahr

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

What it computes

Echo the caller-assigned Goetz 2004 Table 1 modified Hoehn and Yahr stage (1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0) with the published description. No stage 0. magent does not examine the patient.

When to use

When an agent already has a modified Hoehn and Yahr stage as assigned by the caller and needs the published Table 1 description. magent does not examine the patient, assign stage from findings, map to UPDRS, or use the original integer-only 1-5 scale.

When not to use

Not a medical device. magent does not examine the patient.
The caller assigns modified Hoehn and Yahr stage 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0. magent does not examine the patient, perform a pull test, or assign stage from findings.
Not UPDRS. Not a diagnosis. Not an outcome measure.
Goetz 2004 recommended the original 1-5 Hoehn and Yahr scale for group description pending clinimetric testing of the modified form. This tool still implements the widely used modified Table 1 tokens (1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0).
Stage 0 is not in Table 1. This is not the original integer-only 1-5 scale as a separate tool. Not a treatment order.

Formula

hy_stage in {1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0} as assigned by the caller (Goetz 2004 Table 1 modified Hoehn and Yahr). No stage 0. Not the original integer-only 1-5 scale. Not UPDRS. Not a diagnosis. Not an outcome measure.

Citation

Title: Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations
Authors: Goetz CG, Poewe W, Rascol O, Sampaio C, Stebbins GT, Counsell C, Giladi N, Holloway RG, Moore CG, Wenning GK, Yahr MD
Source: Mov Disord. 2004;19(9):1020-1028
DOI: 10.1002/mds.20213

Worked example

Stage 1.0 unilateral involvement only

Given: hy_stage=1.0

hy_stage 1.0 as assigned by the caller
unilateral involvement only

Stage 2.5 mild bilateral with recovery on pull test

Given: hy_stage=2.5

hy_stage 2.5 as assigned by the caller
mild bilateral disease with recovery on pull test

Stage 5.0 wheelchair bound or bedridden unless aided

Given: hy_stage=5.0

hy_stage 5.0 as assigned by the caller
wheelchair bound or bedridden unless aided

Also searched as

modified Hoehn and Yahr
Hoehn Yahr stage
Goetz 2004 Hoehn and Yahr
HY 1.0 1.5 2.5
Parkinson modified stage
pull test Hoehn Yahr
mHY stage
unilateral axial Hoehn Yahr

Try

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

/api/calc/modified_hoehn_yahr?hy_stage=1.0

Full URL: https://api.magentlab.com/api/calc/modified_hoehn_yahr?hy_stage=1.0

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/modified_hoehn_yahr?hy_stage=1.0"

Parameters

Name	Type	Required	Description
`hy_stage`	string	required	Goetz 2004 Table 1 modified Hoehn and Yahr stage as assigned by the caller: 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0 (exact tokens; reject 1, 3, 0, 0.5, 2.5.0). 1.0 unilateral only; 1.5 unilateral and axial; 2.0 bilateral without impairment of balance; 2.5 mild bilateral with recovery on pull test; 3.0 mild to moderate bilateral with some postural instability, physically independent; 4.0 severe disability, still able to walk or stand unassisted; 5.0 wheelchair bound or bedridden unless aided. No stage 0. Not the original integer-only 1-5 scale. Not UPDRS. magent does not examine the patient.

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/modified_hoehn_yahr 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": [
    {
      "hy_stage": "1.0"
    },
    {
      "hy_stage": "1.0"
    }
  ]
}

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/modified_hoehn_yahr",
  "items": [
    {
      "description": "Unilateral involvement only",
      "components": [
        {
          "factor": "stage_1_0",
          "met": true
        },
        {
          "factor": "stage_1_5",
          "met": false
        },
        {
          "factor": "stage_2_0",
          "met": false
        },
        {
          "factor": "stage_2_5",
          "met": false
        },
        {
          "factor": "stage_3_0",
          "met": false
        },
        {
          "factor": "stage_4_0",
          "met": false
        },
        {
          "factor": "stage_5_0",
          "met": 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": "Goetz CG, Poewe W, Rascol O, Sampaio C, Stebbins GT, Counsell C, Giladi N, Holloway RG, Moore CG, Wenning GK, Yahr MD",
        "doi": "10.1002/mds.20213",
        "id": "goetz-2004",
        "pmid": "15372591",
        "source": "Mov Disord. 2004;19(9):1020-1028",
        "title": "Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations"
      },
      "formula": "modified_hoehn_yahr",
      "formula_expression": "hy_stage in {1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0} as assigned by the caller (Goetz 2004 Table 1 modified Hoehn and Yahr). No stage 0. Not the original integer-only 1-5 scale. Not UPDRS. Not a diagnosis. Not an outcome measure.",
      "hy_stage": "1.0"
    },
    {
      "description": "Unilateral involvement only",
      "components": [
        {
          "factor": "stage_1_0",
          "met": true
        },
        {
          "factor": "stage_1_5",
          "met": false
        },
        {
          "factor": "stage_2_0",
          "met": false
        },
        {
          "factor": "stage_2_5",
          "met": false
        },
        {
          "factor": "stage_3_0",
          "met": false
        },
        {
          "factor": "stage_4_0",
          "met": false
        },
        {
          "factor": "stage_5_0",
          "met": 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": "Goetz CG, Poewe W, Rascol O, Sampaio C, Stebbins GT, Counsell C, Giladi N, Holloway RG, Moore CG, Wenning GK, Yahr MD",
        "doi": "10.1002/mds.20213",
        "id": "goetz-2004",
        "pmid": "15372591",
        "source": "Mov Disord. 2004;19(9):1020-1028",
        "title": "Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations"
      },
      "formula": "modified_hoehn_yahr",
      "formula_expression": "hy_stage in {1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0} as assigned by the caller (Goetz 2004 Table 1 modified Hoehn and Yahr). No stage 0. Not the original integer-only 1-5 scale. Not UPDRS. Not a diagnosis. Not an outcome measure.",
      "hy_stage": "1.0"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	modified_hoehn_yahr
`formula_expression`	string	Published Goetz 2004 Table 1 modified Hoehn and Yahr token rule
`hy_stage`	string	Caller-assigned token 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0
`description`	string	Goetz 2004 Table 1 modified-column wording for that stage
`components`	array	Per-stage Tree rows stage_1_0, stage_1_5, stage_2_0, stage_2_5, stage_3_0, stage_4_0, stage_5_0 with factor and met; exactly one is met
`citation`	object	Goetz 2004 Mov Disord citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "description": "Unilateral involvement only",
  "components": [
    {
      "factor": "stage_1_0",
      "met": true
    },
    {
      "factor": "stage_1_5",
      "met": false
    },
    {
      "factor": "stage_2_0",
      "met": false
    },
    {
      "factor": "stage_2_5",
      "met": false
    },
    {
      "factor": "stage_3_0",
      "met": false
    },
    {
      "factor": "stage_4_0",
      "met": false
    },
    {
      "factor": "stage_5_0",
      "met": 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": "Goetz CG, Poewe W, Rascol O, Sampaio C, Stebbins GT, Counsell C, Giladi N, Holloway RG, Moore CG, Wenning GK, Yahr MD",
    "doi": "10.1002/mds.20213",
    "id": "goetz-2004",
    "pmid": "15372591",
    "source": "Mov Disord. 2004;19(9):1020-1028",
    "title": "Movement Disorder Society Task Force report on the Hoehn and Yahr staging scale: status and recommendations"
  },
  "formula": "modified_hoehn_yahr",
  "formula_expression": "hy_stage in {1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0} as assigned by the caller (Goetz 2004 Table 1 modified Hoehn and Yahr). No stage 0. Not the original integer-only 1-5 scale. Not UPDRS. Not a diagnosis. Not an outcome measure.",
  "hy_stage": "1.0"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_modified_hoehn_yahr`	hy_stage must be 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0 (Goetz 2004 modified Hoehn and Yahr Table 1). 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

None.

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.