# CHADS-65 CHADS-65 Status: LIVE Price: $0.005 USDC `GET /api/calc/chads_65` HTML: https://magentlab.com/docs/chads-65 Markdown: https://magentlab.com/docs/chads-65.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Apply the CCS 2014 CHADS-65 algorithm and return oac, asa, or none from age and caller-assigned CHF, hypertension, diabetes, prior stroke/TIA, and vascular disease. ## When to use When an agent needs the CCS 2014 CHADS-65 stroke-prevention algorithm for nonvalvular AF/AFL from caller-assigned age and flags, and must not use CHADS2, CHA2DS2-VASc, or HAS-BLED. ## When not to use - Not a medical device. Not an anticoagulation order. magent does not examine the patient. - This is the Canadian CCS 2014 algorithm for nonvalvular AF/AFL stroke-prevention discussion. It is not CHADS2, not CHA2DS2-VASc, not HAS-BLED, and not a valve or AF diagnosis. - Age ≥75 is subsumed by age ≥65. There is no separate age≥75 input. - Flags are caller-supplied booleans. magent does not infer CHF, stroke, or vascular disease from text. ## Formula ``` OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65) ``` ## Citation [2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation](https://doi.org/10.1016/j.cjca.2014.08.001) Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS Can J Cardiol. 2014;30(10):1114-1130 DOI: [10.1016/j.cjca.2014.08.001](https://doi.org/10.1016/j.cjca.2014.08.001) ## Worked example ### Age 70, all flags false Given: `age=70, chf=false, diabetes=false, hypertension=false, stroke_tia=false, vascular_disease=false` 1. Age 70 ≥ 65 2. recommendation is oac ### Age 50 with vascular disease Given: `age=50, chf=false, diabetes=false, hypertension=false, stroke_tia=false, vascular_disease=true` 1. Age 50 is not ≥ 65; no CHF, hypertension, diabetes, or stroke/TIA 2. vascular_disease is true; recommendation is asa ### Age 50, all flags false Given: `age=50, chf=false, diabetes=false, hypertension=false, stroke_tia=false, vascular_disease=false` 1. Age 50 is not ≥ 65; no CHADS2 factors and no vascular disease 2. recommendation is none ### Age 50 with diabetes Given: `age=50, chf=false, diabetes=true, hypertension=false, stroke_tia=false, vascular_disease=false` 1. Age 50 is not ≥ 65; diabetes is a CHADS2 factor other than age≥75 2. recommendation is oac ## Also searched as - CHADS-65 - CCS algorithm - CCS AF - CCS CHADS-65 - CHADS65 - Canadian AF guidelines - CCS atrial fibrillation - Verma 2014 AF ## Parameters - `age` (integer, required): Age in years (18-120). ≥65 indicates oral anticoagulant (OAC). Age ≥75 is subsumed by ≥65; there is no separate age≥75 input. 64 does not indicate OAC on age alone. - `chf` (boolean, required): Congestive heart failure as assigned by the caller. true or false. Any true CHADS2 factor other than age≥75 (CHF, hypertension, diabetes, prior stroke/TIA) indicates OAC. - `hypertension` (boolean, required): Hypertension history as assigned by the caller. true or false. Indicates OAC when true. - `diabetes` (boolean, required): Diabetes mellitus as assigned by the caller. true or false. Indicates OAC when true. - `stroke_tia` (boolean, required): Prior stroke or TIA as assigned by the caller. true or false. Indicates OAC when true. - `vascular_disease` (boolean, required): Coronary, aortic, or peripheral arterial disease as assigned by the caller. true or false. Indicates ASA only when OAC is not indicated. ## 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/chads_65` 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": "70", "chf": "false", "diabetes": "false", "hypertension": "false", "stroke_tia": "false", "vascular_disease": "false" }, { "age": "70", "chf": "false", "diabetes": "false", "hypertension": "false", "stroke_tia": "false", "vascular_disease": "false" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/chads-65 Example 200: ```json { "count": 2, "path": "/api/calc/chads_65", "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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS", "doi": "10.1016/j.cjca.2014.08.001", "id": "verma-2014", "pmid": "25262857", "source": "Can J Cardiol. 2014;30(10):1114-1130", "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation" }, "formula": "chads_65", "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)", "criteria": [ { "value": 70, "factor": "age_ge_65", "met": true }, { "factor": "chf", "met": false }, { "factor": "hypertension", "met": false }, { "factor": "diabetes", "met": false }, { "factor": "stroke_tia", "met": false }, { "factor": "vascular_disease", "met": false } ], "oac_indicated": true, "recommendation": "oac" }, { "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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS", "doi": "10.1016/j.cjca.2014.08.001", "id": "verma-2014", "pmid": "25262857", "source": "Can J Cardiol. 2014;30(10):1114-1130", "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation" }, "formula": "chads_65", "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)", "criteria": [ { "value": 70, "factor": "age_ge_65", "met": true }, { "factor": "chf", "met": false }, { "factor": "hypertension", "met": false }, { "factor": "diabetes", "met": false }, { "factor": "stroke_tia", "met": false }, { "factor": "vascular_disease", "met": false } ], "oac_indicated": true, "recommendation": "oac" } ] } ``` ## Response fields - `formula` (string): chads_65 - `formula_expression` (string): CCS 2014 CHADS-65 OAC then ASA then none tree - `recommendation` (string): oac, asa, or none. Not an anticoagulation order. - `oac_indicated` (boolean): true when age ≥ 65 or CHF, hypertension, diabetes, or prior stroke/TIA is present - `criteria` (array): Per-factor rows (age_ge_65, chf, hypertension, diabetes, stroke_tia, vascular_disease) with factor, met, and age value on age_ge_65 - `citation` (object): Verma 2014 Can J Cardiol 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": "Verma A, Cairns JA, Mitchell LB, Macle L, Stiell IG, Gladstone D, McMurtry MS, Connolly S, Cox JL, Dorian P, Ivers N, Leblanc K, Nattel S, Healey JS", "doi": "10.1016/j.cjca.2014.08.001", "id": "verma-2014", "pmid": "25262857", "source": "Can J Cardiol. 2014;30(10):1114-1130", "title": "2014 focused update of the Canadian Cardiovascular Society Guidelines for the management of atrial fibrillation" }, "formula": "chads_65", "formula_expression": "OAC if age ≥ 65 or CHF or hypertension or diabetes or prior stroke/TIA; else ASA if vascular disease (coronary, aortic, or peripheral arterial); else none (CCS 2014 CHADS-65)", "criteria": [ { "value": 70, "factor": "age_ge_65", "met": true }, { "factor": "chf", "met": false }, { "factor": "hypertension", "met": false }, { "factor": "diabetes", "met": false }, { "factor": "stroke_tia", "met": false }, { "factor": "vascular_disease", "met": false } ], "oac_indicated": true, "recommendation": "oac" } ``` ## Errors - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false 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 - [CHADS2](https://magentlab.com/docs/chads2) — Compute the CHADS2 stroke-risk score from discrete clinical flags. - [CHA2DS2-VASc](https://magentlab.com/docs/cha2ds2-vasc) — Compute the CHA2DS2-VASc stroke-risk score from discrete clinical flags. ## 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.