{"uid":"cap_XzvhhrpfCA8tWUq3gTAWH","slug":"chads2-stroke-risk-score-calculator-6b8646a9","name":"CHADS2 Stroke Risk Score Calculator","description":"CHADS2 score from discrete clinical flags. Use for the 2001 Gage atrial-fibrillation stroke-risk arithmetic. Deterministic published score with citation; not an anticoagulation order.","url":"https://api.magentlab.com/api/calc/chads2","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["age","chf","hypertension","diabetes","stroke_tia"],"properties":{"age":{"type":"integer","description":"Age in years (18-120). ≥75 scores 1."},"chf":{"type":"boolean","description":"Congestive heart failure or LV dysfunction. true or false."},"diabetes":{"type":"boolean","description":"Diabetes mellitus. true or false."},"stroke_tia":{"type":"boolean","description":"Prior stroke or TIA. true or false (2 points)."},"hypertension":{"type":"boolean","description":"Hypertension history. true or false."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"path":"/api/calc/chads2","count":2,"items":[{"score":3,"formula":"chads2","citation":{"id":"gage-2001","doi":"10.1001/jama.285.22.2864","title":"Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation","source":"JAMA. 2001;285(22):2864-2870","authors":"Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ"},"age_years":78,"max_score":6,"components":[{"factor":"congestive_heart_failure","points":0,"present":false},{"factor":"hypertension","points":1,"present":true},{"value":78,"factor":"age_ge_75","points":1,"present":true},{"factor":"diabetes","points":1,"present":true},{"factor":"stroke_tia","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.","formula_expression":"CHADS2 = CHF 1 + hypertension 1 + age≥75 1 + diabetes 1 + stroke/TIA 2; max 6"},{"score":3,"formula":"chads2","citation":{"id":"gage-2001","doi":"10.1001/jama.285.22.2864","title":"Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation","source":"JAMA. 2001;285(22):2864-2870","authors":"Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ"},"age_years":78,"max_score":6,"components":[{"factor":"congestive_heart_failure","points":0,"present":false},{"factor":"hypertension","points":1,"present":true},{"value":78,"factor":"age_ge_75","points":1,"present":true},{"factor":"diabetes","points":1,"present":true},{"factor":"stroke_tia","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.","formula_expression":"CHADS2 = CHF 1 + hypertension 1 + age≥75 1 + diabetes 1 + stroke/TIA 2; max 6"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_2D-XIA9Av36XfiouvEJrv","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the CHADS2 atrial fibrillation stroke-risk score from five discrete clinical flags using the 2001 Gage methodology","exampleAgentPrompt":"Calculate the CHADS2 stroke risk score for a 78-year-old patient with atrial fibrillation who has hypertension and diabetes but no congestive heart failure and no prior stroke or TIA.","exampleUseCases":[{"title":"Pre-anticoagulation stroke risk stratification","prompt":"My patient is 80 years old with AFib, has a history of hypertension and a prior TIA, but no diabetes or congestive heart failure — what's their CHADS2 score?"},{"title":"EHR-integrated clinical documentation tool","prompt":"Compute the CHADS2 score for a 65-year-old AFib patient who has both congestive heart failure and diabetes, no hypertension, and no prior stroke or TIA."},{"title":"Risk-tier comparison across patient cohort","prompt":"What is the CHADS2 score for a 74-year-old with atrial fibrillation, hypertension, diabetes, and heart failure but no prior stroke or TIA?"}],"resultDescription":"Returns the integer CHADS2 score (0–6) computed from the five input clinical flags per the 2001 Gage methodology, along with interpretive context and the published citation. Higher scores indicate greater annual stroke risk in patients with atrial fibrillation.","failureModes":["Missing required query parameter returns validation error","Age out of valid range (18–120) returns error","Non-boolean value for clinical flag fields returns parsing error","Network timeout if upstream service is unavailable"],"whenToPreferThis":"Use this endpoint when you need a deterministic, citation-backed CHADS2 score calculation based on the original 2001 Gage methodology for atrial fibrillation stroke risk stratification. Prefer this over CHA2DS2-VASc calculators when specifically required to use the simpler 2001 5-factor model. Suitable for automated clinical workflows, EHR enrichment, or decision-support pipelines where reproducible arithmetic and a published citation are required.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:13:44.973Z","isFirstParty":false}