# Gomez 2016 Step-by-Step Febrile Infant Risk Stratification

> Gomez 2016 Step-by-Step Febrile Infant Risk Stratification is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Classifies febrile infants 90 days and younger into high, intermediate, or low risk for serious bacterial infection using the Gomez 2016 Step-by-Step algorithm (Mintegi 2014 derivation).

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/step_by_step
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/gomez-2016-step-by-step-febrile-infant-risk-stratification-c23ad657
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__ZH6TahBNdNHlYpR2RVXE

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 gomez-2016-step-by-step-febrile-infant-risk-stratification-c23ad657
```

Example prompt: Run the Gomez 2016 Step-by-Step febrile infant risk stratification for a 35-day-old infant who is well-appearing, has no leukocyturia, a PCT of 0.3 ng/mL, CRP of 25 mg/L, and ANC of 8500 cells/µL — tell me if they're low, intermediate, or high risk.

## When to prefer this

Choose this endpoint when you need to apply specifically the Gomez 2016 Step-by-Step algorithm (Mintegi 2014 derivation) for febrile infants 0–90 days old using PCT, CRP, ANC, leukocyturia, age, and appearance — as opposed to Rochester, Boston, Philadelphia, or PECARN criteria, which are different rulesets this endpoint does not implement.

## Known failure modes

- Missing required query parameters (age_days, well_appearing, leukocyturia, pct_ng_ml, crp_mg_l, anc_per_ul) returns a validation error
- age_days outside 0–90 range may be rejected or produce unreliable results since the rule is validated only for infants ≤90 days
- Numeric values outside physiologic ranges (e.g. CRP >500, ANC >100000) may be rejected
- Payment failure (x402) if USDC payment is not properly attached

## How this service works

Gomez 2016 Step-by-Step for febrile infants 90 days and younger (derivation Mintegi 2014). High if ill-appearing, age 21 days or younger, leukocyturia, or PCT >=0.5 ng/mL; else intermediate if CRP >20 mg/L or ANC >10000/uL; else low. Returns risk, low_risk, high_risk, and intermediate_risk. magent does not examine the infant or assay UA, PCT, CRP, or ANC. Not Rochester, Boston, Philadelphia, or PECARN febrile. Not a medical device and not a discharge, admission, LP, or antibiotic order.

## Output

Returns a risk category string ('high', 'intermediate', or 'low') along with three boolean flags — low_risk, intermediate_risk, and high_risk — indicating which tier the infant falls into based on the Gomez 2016 Step-by-Step decision tree applied to the provided clinical values.

## 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": [
      "age_days",
      "well_appearing",
      "leukocyturia",
      "pct_ng_ml",
      "crp_mg_l",
      "anc_per_ul"
     ],
     "properties": {
      "age_days": {
       "type": "integer",
       "description": "Chronological age in days (integer 0-90). Gomez 2016 studied febrile infants 90 days and younger. Age 21 days or younger is high-risk. Age 22 can be low-risk when remaining low-risk criteria hold."
      },
      "crp_mg_l": {
       "type": "number",
       "description": "C-reactive protein in mg/L. Range 0-500. Intermediate (when not already high) if greater than 20 mg/L (20 is not intermediate). magent does not assay CRP."
      },
      "pct_ng_ml": {
       "type": "number",
       "description": "Serum procalcitonin in ng/mL. Range 0.01-100. High-risk if 0.5 ng/mL or greater (0.5 is high). Low-risk requires less than 0.5. magent does not assay procalcitonin."
      },
      "anc_per_ul": {
       "type": "number",
       "description": "Absolute neutrophil count in cells/µL. Range 0-100000. Intermediate (when not already high) if greater than 10000/µL (10000 is not intermediate). magent does not assay ANC."
      },
      "leukocyturia": {
       "type": "boolean",
       "description": "Caller-assigned leukocyturia (urine dipstick / UA leukocytes) as used in Gomez 2016. true means leukocytes are present and is high-risk. true or false. magent does not assay UA."
      },
      "well_appearing": {
       "type": "boolean",
       "description": "Caller-assigned well-appearing as used in Gomez 2016. true or false. Ill-appearing (well_appearing=false) is high-risk. magent does not examine the infant."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/gomez-2016-step-by-step-febrile-infant-risk-stratification-c23ad657/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)