{"uid":"cap_zTDLqvWvu4IkpN3cb_o2a","slug":"impact-prognostic-score-for-traumatic-brain-injury-steyerberg-2008-184bd46a","name":"IMPACT Prognostic Score for Traumatic Brain Injury (Steyerberg 2008)","description":"Steyerberg 2008 IMPACT prognostic score for 6-month mortality and unfavorable outcome after traumatic brain injury. model=core (age, motor, pupils), extended (plus hypoxia, hypotension, Marshall CT, tSAH, EDH), or lab (plus glucose mmol/L and Hb g/dL). Points and printed logistic LPs from that paper. Not a diagnosis, not MRC CRASH (Perel 2008), and not magent chemotherapy CRASH.","url":"https://api.magentlab.com/api/calc/impact","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":["model","age","motor_score","pupillary_reactivity"],"properties":{"age":{"type":"integer","description":"Age in years (integer 14-90). Steyerberg 2008 Figure 1: ≤30 → 0; 31–39 → 1; 40–49 → 2; 50–59 → 3; 60–69 → 4; ≥70 → 5. Chart label 30–39 is the decade after ≤30 (age 30 scores 0)."},"edh":{"type":"boolean","description":"Epidural hematoma (Steyerberg 2008). Required when model is extended or lab. true adds −2; false adds 0. Ignored on model=core."},"tsah":{"type":"boolean","description":"Traumatic subarachnoid hemorrhage (Steyerberg 2008). Required when model is extended or lab. true adds 2; false adds 0. Ignored on model=core."},"model":{"enum":["core","extended","lab"],"type":"string","description":"Steyerberg 2008 IMPACT model. core uses age, motor, and pupils. extended adds hypoxia, hypotension, Marshall CT, tSAH, and EDH. lab adds glucose mmol/L and hemoglobin g/dL. Required; magent does not pick a model."},"hypoxia":{"type":"boolean","description":"Hypoxia yes or suspected (Steyerberg 2008). Required when model is extended or lab. true adds 1; false adds 0. Ignored on model=core."},"hypotension":{"type":"boolean","description":"Hypotension yes or suspected (Steyerberg 2008). Required when model is extended or lab. true adds 2; false adds 0. Ignored on model=core."},"marshall_ct":{"enum":["I","II","III","IV","V","VI"],"type":"string","description":"Marshall CT class I–VI (Steyerberg 2008). Required when model is extended or lab. I → −2; II → 0; III, IV, V, or VI → 2. Ignored on model=core. magent does not read the scan."},"motor_score":{"type":"integer","description":"GCS motor integer 1-6 or 9 (untestable/missing) as in Steyerberg 2008. 1 or 2 (none/extension) → 6; 3 (abnormal flexion) → 4; 4 (normal flexion) → 2; 5 or 6 (localizes/obeys) → 0; 9 → 3."},"glucose_mmol_l":{"type":"number","description":"Admission glucose in mmol/L (2.8-55.5). Required when model is lab. Steyerberg 2008: <6 → 0; 6–8.9 → 1; 9–11.9 → 2; 12–14.9 → 3; ≥15 → 4. Ignored on core and extended. magent does not assay glucose."},"hemoglobin_g_dl":{"type":"number","description":"Admission hemoglobin in g/dL (3-22). Required when model is lab. Steyerberg 2008: <9 → 3; 9–11.9 → 2; 12–14.9 → 1; ≥15 → 0. Ignored on core and extended. magent does not assay hemoglobin."},"pupillary_reactivity":{"enum":["both","one","none"],"type":"string","description":"Pupillary reactivity (Steyerberg 2008). both → 0; one → 2; none → 4. Caller-assigned. magent does not examine pupils."}}}},"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_lw_cCniAhTVAbAEOk7LRE","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":"Calculates the Steyerberg 2008 IMPACT prognostic score for 6-month mortality and unfavorable outcome after traumatic brain injury using core, extended, or lab model variants.","exampleAgentPrompt":"Calculate the IMPACT extended model prognostic score for a 55-year-old TBI patient with a GCS motor score of 2, both pupils non-reactive, hypoxia present, no hypotension, Marshall CT class III, tSAH present, and no epidural hematoma.","exampleUseCases":[{"title":"ICU admission TBI risk stratification","prompt":"Run the IMPACT core model for a 68-year-old TBI patient with a motor score of 3 and one reactive pupil — what's their estimated 6-month mortality and unfavorable outcome probability?"},{"title":"Neuro-ICU extended model assessment","prompt":"Use the IMPACT extended model to score a 42-year-old severe TBI patient: motor score 1, both pupils unreactive, hypoxia suspected, hypotension no, Marshall CT class IV, tSAH yes, EDH no."},{"title":"Lab model with metabolic data","prompt":"Compute the Steyerberg 2008 IMPACT lab model for a 35-year-old with GCS motor 4, one non-reactive pupil, no hypoxia, no hypotension, Marshall CT class II, no tSAH, no EDH, glucose 8.2 mmol/L, and hemoglobin 10.5 g/dL."}],"resultDescription":"Returns the IMPACT point total, the logistic regression linear predictor (LP) for both 6-month mortality and unfavorable outcome, and the derived probability estimates, all computed from the published Steyerberg 2008 scoring table and logistic function coefficients.","failureModes":["Missing required parameters (model, age, motor_score, pupillary_reactivity) returns a 400 error","Extended/lab model fields (hypoxia, hypotension, marshall_ct, tsah, edh) missing when model=extended or lab causes validation error","Age outside valid range (14–90) or motor score outside 1–6 may be rejected or clamped","Invalid marshall_ct enum value (not I–VI) returns error","Payment not included or insufficient results in 402 Payment Required"],"whenToPreferThis":"Choose this endpoint when you need to apply the published Steyerberg 2008 IMPACT prognostic model specifically — not MRC CRASH (Perel 2008) and not any chemotherapy protocol. Use when you need deterministic, point-for-point reproduction of the original paper's scoring table and logistic linear predictors for 6-month post-TBI outcomes, including choice between core (3 variables), extended (8 variables), or lab (10 variables) model tiers.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T13:04:36.349Z","isFirstParty":false}