# IMPACT Prognostic Score for Traumatic Brain Injury (Steyerberg 2008)

> IMPACT Prognostic Score for Traumatic Brain Injury (Steyerberg 2008) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

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.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/impact
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/impact-prognostic-score-for-traumatic-brain-injury-steyerberg-2008-184bd46a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zTDLqvWvu4IkpN3cb_o2a

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability impact-prognostic-score-for-traumatic-brain-injury-steyerberg-2008-184bd46a
```

Example prompt: 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.

## When to prefer this

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.

## Known failure modes

- 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

## How this service works

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.

## Output

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.

## Request schema (JSON Schema)

```json
{
 "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 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/impact-prognostic-score-for-traumatic-brain-injury-steyerberg-2008-184bd46a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)