# Patient Activity Scale (PAS) for RA

PAS-RA

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

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

## What it computes

Compute the Wolfe 2005 Patient Activity Scale (PAS) from a caller-assigned HAQ disability index (0-3), pain VAS (0-10), and patient global VAS (0-10). Uses HAQ × 3.33, not HAQ-II. Returns the PAS total only.

## When to use

When an agent already has a caller-assigned HAQ (0-3, not HAQ-II), pain VAS, and patient global VAS and needs the published Wolfe 2005 PAS composite, not PAS-II, not DAS28, not CDAI, and not Samuel 2002 pediatric appendicitis PAS.

## When not to use

- Not a medical device and not a rheumatoid arthritis diagnosis or a treatment order.
- magent does not administer the HAQ. haq, pain_vas, and patient_global_vas are caller-assigned. This tool uses HAQ 0-3, not HAQ-II.
- This is Wolfe 2005 PAS (HAQ × 3.33), not PAS-II (HAQ-II). Not Samuel 2002 pediatric appendicitis PAS. Not DAS28. Not CDAI.
- Wolfe 2005 does not lock remission, minimal, moderate, or severe cutoffs in this tool. magent returns the PAS total only.

## Formula

```
PAS = (haq * 3.33 + pain_vas + patient_global_vas) / 3; Wolfe 2005 Patient Activity Scale (not PAS-II); HAQ 0-3 (not HAQ-II); pain and patient global 0-10 VAS; magent does not administer the HAQ; not Samuel 2002 pediatric appendicitis PAS; not DAS28; not CDAI; not a diagnosis; no published remission/minimal/moderate/severe cutoffs
```

## Citation

[A composite disease activity scale for clinical practice, observational studies, and clinical trials: the patient activity scale (PAS/PAS-II)](https://pubmed.ncbi.nlm.nih.gov/16331773)
Wolfe F, Michaud K, Pincus T
J Rheumatol. 2005;32(12):2410-2415
DOI: none

## Worked example

### Clinical zeros

Given: `haq=0, pain_vas=0, patient_global_vas=0`

1. PAS = (0 * 3.33 + 0 + 0) / 3
2. pas = 0.00. No activity-state cutoff.


### HAQ 1 with mid VAS

Given: `haq=1, pain_vas=5, patient_global_vas=5`

1. PAS = (1 * 3.33 + 5 + 5) / 3 = 13.33 / 3
2. pas rounded to 2 decimals. No activity-state cutoff.


## Also searched as

- Patient Activity Scale
- PAS RA
- Wolfe PAS
- HAQ pain patient global
- rheumatoid arthritis PAS
- PAS not PAS-II
- Wolfe 2005 PAS

## Parameters

- `haq` (number, required): Caller-assigned HAQ disability index (Wolfe 2005 PAS). Number 0-3. Not HAQ-II. magent does not administer the HAQ.
- `pain_vas` (number, required): Caller-assigned pain visual analog scale (Wolfe 2005 PAS). Number 0-10. magent does not examine the patient.
- `patient_global_vas` (number, required): Caller-assigned patient global visual analog scale (Wolfe 2005 PAS). Number 0-10. 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.

Method: `POST /api/calc/pas_ra`
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": [
    {
      "haq": "0",
      "pain_vas": "0",
      "patient_global_vas": "0"
    },
    {
      "haq": "0",
      "pain_vas": "0",
      "patient_global_vas": "0"
    }
  ]
}
```

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

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/pas_ra",
  "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": "Wolfe F, Michaud K, Pincus T",
        "id": "wolfe-2005",
        "pmid": "16331773",
        "source": "J Rheumatol. 2005;32(12):2410-2415",
        "title": "A composite disease activity scale for clinical practice, observational studies, and clinical trials: the patient activity scale (PAS/PAS-II)"
      },
      "formula": "pas_ra",
      "formula_expression": "PAS = (haq * 3.33 + pain_vas + patient_global_vas) / 3; Wolfe 2005 Patient Activity Scale (not PAS-II); HAQ 0-3 (not HAQ-II); pain and patient global 0-10 VAS; magent does not administer the HAQ; not Samuel 2002 pediatric appendicitis PAS; not DAS28; not CDAI; not a diagnosis; no published remission/minimal/moderate/severe cutoffs",
      "pain_vas": 0.0,
      "patient_global_vas": 0.0,
      "haq": 0.0,
      "pas": 0.0
    },
    {
      "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": "Wolfe F, Michaud K, Pincus T",
        "id": "wolfe-2005",
        "pmid": "16331773",
        "source": "J Rheumatol. 2005;32(12):2410-2415",
        "title": "A composite disease activity scale for clinical practice, observational studies, and clinical trials: the patient activity scale (PAS/PAS-II)"
      },
      "formula": "pas_ra",
      "formula_expression": "PAS = (haq * 3.33 + pain_vas + patient_global_vas) / 3; Wolfe 2005 Patient Activity Scale (not PAS-II); HAQ 0-3 (not HAQ-II); pain and patient global 0-10 VAS; magent does not administer the HAQ; not Samuel 2002 pediatric appendicitis PAS; not DAS28; not CDAI; not a diagnosis; no published remission/minimal/moderate/severe cutoffs",
      "pain_vas": 0.0,
      "patient_global_vas": 0.0,
      "haq": 0.0,
      "pas": 0.0
    }
  ]
}
```

## Response fields

- `formula` (string): pas_ra
- `formula_expression` (string): Exact expression used
- `haq` (number): HAQ disability index used (0-3, not HAQ-II)
- `pain_vas` (number): Pain VAS used (0-10)
- `patient_global_vas` (number): Patient global VAS used (0-10)
- `pas` (number): Wolfe 2005 PAS total, 2 decimals: (haq * 3.33 + pain_vas + patient_global_vas) / 3. No activity-state cutoffs.
- `citation` (object): Wolfe, Michaud, and Pincus 2005 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": "Wolfe F, Michaud K, Pincus T",
    "id": "wolfe-2005",
    "pmid": "16331773",
    "source": "J Rheumatol. 2005;32(12):2410-2415",
    "title": "A composite disease activity scale for clinical practice, observational studies, and clinical trials: the patient activity scale (PAS/PAS-II)"
  },
  "formula": "pas_ra",
  "formula_expression": "PAS = (haq * 3.33 + pain_vas + patient_global_vas) / 3; Wolfe 2005 Patient Activity Scale (not PAS-II); HAQ 0-3 (not HAQ-II); pain and patient global 0-10 VAS; magent does not administer the HAQ; not Samuel 2002 pediatric appendicitis PAS; not DAS28; not CDAI; not a diagnosis; no published remission/minimal/moderate/severe cutoffs",
  "pain_vas": 0.0,
  "patient_global_vas": 0.0,
  "haq": 0.0,
  "pas": 0.0
}
```

## Errors

- HTTP 400 `invalid_haq`: haq must be a number from 0 to 3 (Wolfe 2005 HAQ 0-3). Returned before settlement; you are not charged.
- HTTP 400 `invalid_pain_vas`: pain_vas must be a number from 0 to 10 (Wolfe 2005 pain VAS). Returned before settlement; you are not charged.
- HTTP 400 `invalid_patient_global`: patient_global_vas must be a number from 0 to 10 (Wolfe 2005 patient global VAS). 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

- [DAS28-ESR](https://magentlab.com/docs/das28-esr) — Compute the Prevoo 1995 28-joint DAS with ESR from caller-assigned tender and swollen 28-joint counts, ESR in mm/h, and patient general health on a 0-100 mm VAS. Returns the published score only.
- [CDAI-RA](https://magentlab.com/docs/cdai-ra) — Sum caller-assigned 28-joint swollen and tender counts and 0–10 cm patient and evaluator globals and return the Aletaha 2005 Clinical Disease Activity Index. Does not add CRP and does not return activity-state cutoffs.

## 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.