# AMT-4 abbreviated mental test (Swain) AMT-4 Status: LIVE Price: $0.005 USDC `GET /api/calc/amt_4` HTML: https://magentlab.com/docs/amt-4 Markdown: https://magentlab.com/docs/amt-4.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum the four Swain 1997 AMT-4 items from caller-assigned correct/incorrect flags and return whether the score is less than 4 (impaired). ## When to use When an agent already has AMT-4 items assigned as correct or incorrect (age, date of birth, place, year) and needs the published 0–4 total and impaired flag, not a dementia diagnosis and not Hodkinson 1972 AMT-10. ## When not to use - Not a medical device and not a dementia diagnosis. magent does not interview the patient. - Each item is a caller-assigned boolean (age_correct, dob_correct, place_correct, year_correct). This API does not collect an age, date of birth, place name, or year. - Impaired is true when the AMT-4 score is less than 4 (Swain 1997). Score 4 is not impaired. This is a screening total, not a diagnosis. - This is Swain 1997 AMT-4 only. It is not Hodkinson 1972 AMT-10. ## Formula ``` AMT-4 = age_correct + dob_correct + place_correct + year_correct; each 1 if true; max 4; impaired iff score < 4 (Swain 1997) ``` ## Citation [Evaluation of a shortened version of the Abbreviated Mental Test in a series of elderly patients](https://doi.org/10.1177/026921559701100308) Swain DG, Nightingale PG Clin Rehabil. 1997;11(3):243-248 DOI: [10.1177/026921559701100308](https://doi.org/10.1177/026921559701100308) ## Worked example ### All four items correct Given: `age_correct=true, dob_correct=true, place_correct=true, year_correct=true` 1. age_correct, dob_correct, place_correct, and year_correct are true as assigned by the caller 2. Score = 4 (max 4); impaired false ### Age incorrect, other items correct Given: `age_correct=false, dob_correct=true, place_correct=true, year_correct=true` 1. age_correct false → 0; the other three items true → 1 each 2. Score = 3 (max 4); impaired true because score < 4 ## Also searched as - AMT-4 - Abbreviated Mental Test 4 - Swain AMT-4 - AMT4 - four-item abbreviated mental test - AMT-4 cognitive screen - abbreviated mental test four items - Swain 1997 AMT-4 ## Parameters - `age_correct` (boolean, required): Caller-assigned flag: age stated correctly (Swain 1997 AMT-4). true scores 1; false scores 0. magent does not interview the patient and does not collect an age. - `dob_correct` (boolean, required): Caller-assigned flag: date of birth stated correctly (Swain 1997 AMT-4). true scores 1; false scores 0. magent does not collect a date of birth. - `place_correct` (boolean, required): Caller-assigned flag: place stated correctly (Swain 1997 AMT-4). true scores 1; false scores 0. magent does not collect a place name. - `year_correct` (boolean, required): Caller-assigned flag: current year stated correctly (Swain 1997 AMT-4). true scores 1; false scores 0. magent does not collect a year. ## 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/amt_4` 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_correct": "true", "dob_correct": "true", "place_correct": "true", "year_correct": "true" }, { "age_correct": "true", "dob_correct": "true", "place_correct": "true", "year_correct": "true" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/amt-4 Example 200: ```json { "count": 2, "path": "/api/calc/amt_4", "items": [ { "components": [ { "factor": "age_correct", "points": 1, "present": true }, { "factor": "dob_correct", "points": 1, "present": true }, { "factor": "place_correct", "points": 1, "present": true }, { "factor": "year_correct", "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": "Swain DG, Nightingale PG", "doi": "10.1177/026921559701100308", "id": "swain-1997", "pmid": "9360037", "source": "Clin Rehabil. 1997;11(3):243-248", "title": "Evaluation of a shortened version of the Abbreviated Mental Test in a series of elderly patients" }, "formula": "amt_4", "formula_expression": "AMT-4 = age_correct + dob_correct + place_correct + year_correct; each 1 if true; max 4; impaired iff score < 4 (Swain 1997)", "max_score": 4, "score": 4, "impaired": false }, { "components": [ { "factor": "age_correct", "points": 1, "present": true }, { "factor": "dob_correct", "points": 1, "present": true }, { "factor": "place_correct", "points": 1, "present": true }, { "factor": "year_correct", "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": "Swain DG, Nightingale PG", "doi": "10.1177/026921559701100308", "id": "swain-1997", "pmid": "9360037", "source": "Clin Rehabil. 1997;11(3):243-248", "title": "Evaluation of a shortened version of the Abbreviated Mental Test in a series of elderly patients" }, "formula": "amt_4", "formula_expression": "AMT-4 = age_correct + dob_correct + place_correct + year_correct; each 1 if true; max 4; impaired iff score < 4 (Swain 1997)", "max_score": 4, "score": 4, "impaired": false } ] } ``` ## Response fields - `formula` (string): amt_4 - `formula_expression` (string): Exact expression used - `score` (integer): AMT-4 points 0-4 (Swain 1997) - `max_score` (integer): Always 4 - `impaired` (boolean): true when score is less than 4 (0–3 impaired; 4 not impaired). Swain 1997 screening total, not a dementia diagnosis. - `components` (array): Per-item points - `citation` (object): Swain 1997 Clin Rehabil citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "factor": "age_correct", "points": 1, "present": true }, { "factor": "dob_correct", "points": 1, "present": true }, { "factor": "place_correct", "points": 1, "present": true }, { "factor": "year_correct", "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": "Swain DG, Nightingale PG", "doi": "10.1177/026921559701100308", "id": "swain-1997", "pmid": "9360037", "source": "Clin Rehabil. 1997;11(3):243-248", "title": "Evaluation of a shortened version of the Abbreviated Mental Test in a series of elderly patients" }, "formula": "amt_4", "formula_expression": "AMT-4 = age_correct + dob_correct + place_correct + year_correct; each 1 if true; max 4; impaired iff score < 4 (Swain 1997)", "max_score": 4, "score": 4, "impaired": false } ``` ## Errors - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_amt_4`: each AMT-4 item must be true or false as assigned by the caller (Swain 1997). 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 - [4AT](https://magentlab.com/docs/4at) — Sum the Bellelli 2014 4AT items and return unlikely (0), possible cognitive impairment (1–3), or possible delirium (≥4). ## 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.