{"uid":"cap_wbMZ-81WRrrsO4z1anOyS","slug":"isaric-4c-mortality-score-calculator-knight-2020-e70bdff8","name":"ISARIC 4C Mortality Score Calculator (Knight 2020)","description":"Knight 2020 ISARIC 4C Mortality Score: age (<50→0, 50–59→2, 60–69→4, 70–79→6, ≥80→7) + male 1 + comorbidity_count (0/1/≥2 → 0/1/2; caller-assigned Charlson-plus-obesity count) + RR (<20→0, 20–29→1, ≥30→2) + room-air SpO2 (<92→2) + GCS (<15→2) + urea (<7→0, 7–14→1, >14→3 mmol/L; or BUN/2.8) + CRP (<50→0, 50–99→1, ≥100→2). Max 21. Table 5: low 0–3, intermediate 4–8, high 9–14, very high ≥15. Not a COVID-19 diagnosis or treatment order.","url":"https://api.magentlab.com/api/calc/4c","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","sex","comorbidity_count","respiratory_rate","spo2_percent","gcs","crp_mg_l"],"properties":{"age":{"type":"integer","description":"Age in years (18-120). Knight 2020 Table 2: <50 scores 0; 50–59 scores 2; 60–69 scores 4; 70–79 scores 6; ≥80 scores 7."},"gcs":{"type":"integer","description":"Caller-assigned total GCS as an integer 3–15. 15 scores 0; <15 scores 2 (Knight 2020). This API does not collect eye, verbal, or motor components."},"sex":{"enum":["female","male"],"type":"string","description":"Sex at birth (Knight 2020). female scores 0; male scores 1."},"crp_mg_l":{"type":"number","description":"C-reactive protein in mg/L (0–500). Knight 2020: <50 scores 0; 50–99 scores 1; ≥100 scores 2."},"bun_mg_dl":{"type":"number","description":"BUN in mg/dL (3–140). Converted as urea_mmol_l = bun_mg_dl / 2.8."},"urea_mmol_l":{"type":"number","description":"Serum urea in mmol/L (1–50). Provide this or bun_mg_dl, not both. Knight 2020: <7 scores 0; 7–14 inclusive scores 1; >14 scores 3."},"spo2_percent":{"type":"number","description":"Room-air SpO2 percent (50–100). Knight 2020: ≥92 scores 0; <92 scores 2. magent does not measure saturation."},"respiratory_rate":{"type":"integer","description":"Respiratory rate in breaths/min (integer 4–80). Knight 2020: <20 scores 0; 20–29 scores 1; ≥30 scores 2. magent does not measure vitals."},"comorbidity_count":{"type":"integer","description":"Caller-assigned count of Charlson-plus-obesity comorbidities from Knight 2020 (integer 0–20). 0 scores 0; 1 scores 1; ≥2 scores 2. magent does not compute Charlson."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"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_QhX94SxAYcnqhH4GJX0Ca","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 ISARIC 4C Mortality Score for COVID-19 hospitalized patients using age, sex, comorbidities, respiratory rate, SpO2, GCS, urea/BUN, and CRP, returning a score (0–21) and risk band.","exampleAgentPrompt":"Calculate the ISARIC 4C Mortality Score for a 68-year-old male patient with 2 comorbidities, respiratory rate of 24, room-air SpO2 of 90%, GCS of 15, urea of 8 mmol/L, and CRP of 85 mg/L.","exampleUseCases":[{"title":"ED triage of COVID-19 admission","prompt":"I have a 74-year-old female COVID patient in the ED, 1 comorbidity, respiratory rate 22, SpO2 93% on room air, GCS 15, urea 10 mmol/L, CRP 110 mg/L — what's her 4C Mortality Score and risk band?"},{"title":"ICU vs ward admission decision","prompt":"Help me decide on ward vs ICU for this 82-year-old male COVID patient: 3 comorbidities, RR 31, SpO2 88% on room air, GCS 13, BUN 45 mg/dL, CRP 200 mg/L — run the Knight 2020 4C score."},{"title":"Research cohort risk stratification","prompt":"For my COVID outcomes dataset, calculate the 4C Mortality Score for a 55-year-old male with 0 comorbidities, RR 19, SpO2 94%, GCS 15, urea 6 mmol/L, and CRP 40 mg/L so I can assign a risk band."}],"resultDescription":"Returns the integer 4C Mortality Score (0–21) and a risk band label (low: 0–3, intermediate: 4–8, high: 9–14, very high: ≥15), along with per-component subscores corresponding to the Knight 2020 Table 2 breakpoints.","failureModes":["Missing required parameter (age, sex, comorbidity_count, respiratory_rate, spo2_percent, gcs, crp_mg_l) returns a 400 error","Providing both urea_mmol_l and bun_mg_dl simultaneously causes a validation error","Out-of-range values (e.g. SpO2 >100, age <18, GCS <3 or >15) return validation errors","Score is for clinical decision support only; caller must ensure inputs are clinically accurate as the API does not measure or verify vitals","Payment failure (insufficient USDC balance) returns 402 with x402 payment challenge"],"whenToPreferThis":"Choose this endpoint when you need a validated, published COVID-19 in-hospital mortality risk score (Knight 2020 ISARIC 4C) with deterministic arithmetic and clear risk banding. Prefer it over general ML-based risk models when auditability and alignment with published clinical literature are required. It is especially suitable for clinical decision-support pipelines, EHR integrations, and research cohort stratification where the exact Knight 2020 scoring table must be applied consistently.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T13:11:21.483Z","isFirstParty":false}