# Tisdale QT prolongation risk score Tisdale Status: LIVE Price: $0.005 USDC `GET /api/calc/tisdale` HTML: https://magentlab.com/docs/tisdale Markdown: https://magentlab.com/docs/tisdale.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum Tisdale 2013 Table 5 points for in-hospital QT prolongation risk and return the published 0-6 / 7-10 / ≥11 band. ## When to use When an agent needs the published Tisdale point total and must not invent a drug-stop or TdP decision from prose. ## When not to use - Not a medical device. - Not a drug-stop protocol and not a TdP (torsades de pointes) diagnosis. - The caller assigns clinical flags and the QTc-prolonging drug count. magent does not interpret the ECG or identify the drugs. - Bands follow Tisdale 2013 validation (low <7, moderate 7-10, high ≥11). Table 6 “>11” is a typesetting gap; 11 is high. This tool does not return percents. ## Formula ``` Tisdale = age≥68 1 + female 1 + loop_diuretic 1 + potassium≤3.5 2 + admission_QTc≥450 2 + acute_MI 2 + sepsis 3 + heart_failure 3 + one_QTc_prolonging_drug 3 + ≥2_QTc_prolonging_drugs 3; Table 5; max 21; bands 0-6 / 7-10 / ≥11 ``` ## Citation [Development and validation of a risk score to predict QT interval prolongation in hospitalized patients](https://doi.org/10.1161/CIRCOUTCOMES.113.000152) Tisdale JE, Jaynes HA, Kingery JR, et al. Circ Cardiovasc Qual Outcomes. 2013;6(4):479-487 DOI: [10.1161/CIRCOUTCOMES.113.000152](https://doi.org/10.1161/CIRCOUTCOMES.113.000152) ## Worked example ### No Table 5 factors Given: `acute_mi=false, admission_qtc_ms=400, age=60, heart_failure=false, loop_diuretic=false, potassium_mmol_l=4.0, qtc_prolonging_drugs=0, sepsis=false, sex=male` 1. Age 60 <68 → 0; male → 0; loop false → 0; K 4.0 >3.5 → 0; QTc 400 <450 → 0; MI/sepsis/HF false → 0; drugs 0 → 0 2. Score = 0 (max 21); tisdale_band 0-6 ### K ≤3.5, sepsis, heart failure, one QTc-prolonging drug Given: `acute_mi=false, admission_qtc_ms=400, age=60, heart_failure=true, loop_diuretic=false, potassium_mmol_l=3.5, qtc_prolonging_drugs=1, sepsis=true, sex=male` 1. K 3.5 → 2; sepsis → 3; heart failure → 3; one QTc-prolonging drug → 3 2. Score = 11 (max 21); tisdale_band >=11 ## Also searched as - Tisdale score - Tisdale QT risk score - QT prolongation risk score - hospital QTc risk score - Tisdale 2013 - QTc prolonging drugs risk ## Parameters - `age` (integer, required): Age in years (18-120). Age ≥68 scores 1 (Tisdale 2013 Table 5). 67 does not score. - `sex` (string, required): female scores 1; male scores 0 (Tisdale 2013 Table 5). - `loop_diuretic` (boolean, required): Loop diuretic (Tisdale 2013 Table 5). true or false. Scores 1 if true. - `potassium_mmol_l` (number, required): Serum potassium in mmol/L (1.5-8.0). ≤3.5 scores 2 (Tisdale 2013 Table 5). 3.5 scores; 3.51 does not. - `admission_qtc_ms` (number, required): Admission QTc in milliseconds (200-800). ≥450 scores 2 (Tisdale 2013 Table 5). 450 scores. - `acute_mi` (boolean, required): Acute myocardial infarction (Tisdale 2013 Table 5). true or false. Scores 2 if true. - `sepsis` (boolean, required): Sepsis (Tisdale 2013 Table 5). true or false. Scores 3 if true. - `heart_failure` (boolean, required): Left ventricular dysfunction / heart failure (Tisdale 2013 Table 5). true or false. Scores 3 if true. - `qtc_prolonging_drugs` (integer, required): Count of QTc-prolonging drugs (integer 0-20). 0 → 0 points; 1 → 3 points; ≥2 → 6 points (Table 5 one-drug and ≥2-drug rows stack). ## 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/tisdale` 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": [ { "acute_mi": "false", "admission_qtc_ms": "400", "age": "60", "heart_failure": "false", "loop_diuretic": "false", "potassium_mmol_l": "4.0", "qtc_prolonging_drugs": "0", "sepsis": "false", "sex": "male" }, { "acute_mi": "false", "admission_qtc_ms": "400", "age": "60", "heart_failure": "false", "loop_diuretic": "false", "potassium_mmol_l": "4.0", "qtc_prolonging_drugs": "0", "sepsis": "false", "sex": "male" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/tisdale Example 200: ```json { "count": 2, "path": "/api/calc/tisdale", "items": [ { "components": [ { "value": 60, "factor": "age_ge_68", "points": 0, "present": false }, { "factor": "female", "points": 0, "present": false }, { "factor": "loop_diuretic", "points": 0, "present": false }, { "value": 4.0, "factor": "potassium_le_3_5", "points": 0, "present": false }, { "value": 400.0, "factor": "admission_qtc_ge_450", "points": 0, "present": false }, { "factor": "acute_mi", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false }, { "value": 0, "factor": "one_qtc_prolonging_drug", "points": 0, "present": false }, { "value": 0, "factor": "two_or_more_qtc_prolonging_drugs", "points": 0, "present": 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.", "age_years": 60, "citation": { "authors": "Tisdale JE, Jaynes HA, Kingery JR, et al.", "doi": "10.1161/CIRCOUTCOMES.113.000152", "id": "tisdale-2013", "pmid": "23716032", "source": "Circ Cardiovasc Qual Outcomes. 2013;6(4):479-487", "title": "Development and validation of a risk score to predict QT interval prolongation in hospitalized patients" }, "formula": "tisdale", "formula_expression": "Tisdale = age≥68 1 + female 1 + loop_diuretic 1 + potassium≤3.5 2 + admission_QTc≥450 2 + acute_MI 2 + sepsis 3 + heart_failure 3 + one_QTc_prolonging_drug 3 + ≥2_QTc_prolonging_drugs 3; Table 5; max 21; bands 0-6 / 7-10 / ≥11", "max_score": 21, "score": 0, "sex": "male", "potassium_mmol_l": 4.0, "admission_qtc_ms": 400.0, "qtc_prolonging_drugs": 0, "tisdale_band": "0-6" }, { "components": [ { "value": 60, "factor": "age_ge_68", "points": 0, "present": false }, { "factor": "female", "points": 0, "present": false }, { "factor": "loop_diuretic", "points": 0, "present": false }, { "value": 4.0, "factor": "potassium_le_3_5", "points": 0, "present": false }, { "value": 400.0, "factor": "admission_qtc_ge_450", "points": 0, "present": false }, { "factor": "acute_mi", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false }, { "value": 0, "factor": "one_qtc_prolonging_drug", "points": 0, "present": false }, { "value": 0, "factor": "two_or_more_qtc_prolonging_drugs", "points": 0, "present": 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.", "age_years": 60, "citation": { "authors": "Tisdale JE, Jaynes HA, Kingery JR, et al.", "doi": "10.1161/CIRCOUTCOMES.113.000152", "id": "tisdale-2013", "pmid": "23716032", "source": "Circ Cardiovasc Qual Outcomes. 2013;6(4):479-487", "title": "Development and validation of a risk score to predict QT interval prolongation in hospitalized patients" }, "formula": "tisdale", "formula_expression": "Tisdale = age≥68 1 + female 1 + loop_diuretic 1 + potassium≤3.5 2 + admission_QTc≥450 2 + acute_MI 2 + sepsis 3 + heart_failure 3 + one_QTc_prolonging_drug 3 + ≥2_QTc_prolonging_drugs 3; Table 5; max 21; bands 0-6 / 7-10 / ≥11", "max_score": 21, "score": 0, "sex": "male", "potassium_mmol_l": 4.0, "admission_qtc_ms": 400.0, "qtc_prolonging_drugs": 0, "tisdale_band": "0-6" } ] } ``` ## Response fields - `formula` (string): tisdale - `formula_expression` (string): Exact expression used - `score` (integer): Tisdale 2013 Table 5 points 0-21 - `max_score` (integer): 21 - `tisdale_band` (string): Validation band: 0-6 (low, score <7), 7-10 (moderate), or >=11 (high). Score 11 is high. Not a percent. - `age_years` (integer): Age used for the ≥68 point - `sex` (string): female or male - `potassium_mmol_l` (number): Serum potassium in mmol/L - `admission_qtc_ms` (number): Admission QTc in ms - `qtc_prolonging_drugs` (integer): Caller-assigned QTc-prolonging drug count 0-20 - `components` (array): Per-factor points (Table 5 rows, including stacked drug rows) - `citation` (object): Tisdale et al. Circ Cardiovasc Qual Outcomes 2013 citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": 60, "factor": "age_ge_68", "points": 0, "present": false }, { "factor": "female", "points": 0, "present": false }, { "factor": "loop_diuretic", "points": 0, "present": false }, { "value": 4.0, "factor": "potassium_le_3_5", "points": 0, "present": false }, { "value": 400.0, "factor": "admission_qtc_ge_450", "points": 0, "present": false }, { "factor": "acute_mi", "points": 0, "present": false }, { "factor": "sepsis", "points": 0, "present": false }, { "factor": "heart_failure", "points": 0, "present": false }, { "value": 0, "factor": "one_qtc_prolonging_drug", "points": 0, "present": false }, { "value": 0, "factor": "two_or_more_qtc_prolonging_drugs", "points": 0, "present": 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.", "age_years": 60, "citation": { "authors": "Tisdale JE, Jaynes HA, Kingery JR, et al.", "doi": "10.1161/CIRCOUTCOMES.113.000152", "id": "tisdale-2013", "pmid": "23716032", "source": "Circ Cardiovasc Qual Outcomes. 2013;6(4):479-487", "title": "Development and validation of a risk score to predict QT interval prolongation in hospitalized patients" }, "formula": "tisdale", "formula_expression": "Tisdale = age≥68 1 + female 1 + loop_diuretic 1 + potassium≤3.5 2 + admission_QTc≥450 2 + acute_MI 2 + sepsis 3 + heart_failure 3 + one_QTc_prolonging_drug 3 + ≥2_QTc_prolonging_drugs 3; Table 5; max 21; bands 0-6 / 7-10 / ≥11", "max_score": 21, "score": 0, "sex": "male", "potassium_mmol_l": 4.0, "admission_qtc_ms": 400.0, "qtc_prolonging_drugs": 0, "tisdale_band": "0-6" } ``` ## Errors - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_sex`: sex must be female or male 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_potassium`: potassium_mmol_l must be a number from 1.5 to 8.0. Returned before settlement; you are not charged. - HTTP 400 `invalid_admission_qtc`: admission_qtc_ms must be a number from 200 to 800 (Tisdale 2013). Returned before settlement; you are not charged. - HTTP 400 `invalid_qtc_drug_count`: qtc_prolonging_drugs must be an integer from 0 to 20 (Tisdale 2013). 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 - [QTc](https://magentlab.com/docs/qtc) — Compute heart-rate-corrected QT using Bazett or Fridericia. The formula argument is required. ## 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 echoing accepted, payload, and extensions when present). - 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. - 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.