# Rochester criteria for febrile infants

Rochester criteria

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/rochester`
HTML: https://magentlab.com/docs/rochester
Markdown: https://magentlab.com/docs/rochester.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Apply the Dagan 1985 Rochester criteria and return low_risk only when every published criterion holds for an infant younger than 3 months.

## When to use

When an agent already has Dagan 1985 Rochester findings as assigned by the caller and needs the published all-criteria low-risk boolean. magent does not examine the infant. Not Boston, Philadelphia, or PECARN febrile infant 2021.

## When not to use

- Not a medical device.
- magent does not examine the infant. The caller assigns published yes/no findings and laboratory values.
- This tool is the Dagan 1985 Rochester criteria only. Not Boston criteria, not Philadelphia criteria, and not PECARN febrile infant 2021.
- Not a diagnosis of serious bacterial infection and not a discharge, admission, LP, or antibiotic order.
- Eligible age is younger than 3 months (age_days 0-89). Age 90 is accepted as a parameter but is not low-risk.
- Returns the published low-risk boolean only. Does not report SBI percentages.

## Formula

```
low_risk iff age_days < 90 and previously_healthy and well_appearing and no_focal_infection and 5000 <= wbc_ul <= 15000 and abc_ul < 1500 and ua_wbc_le_10 and (not diarrhea or stool_wbc_le_5) (Dagan 1985)
```

## Citation

[Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis](https://doi.org/10.1016/s0022-3476(85)80175-x)
Dagan R, Powell KR, Hall CB, Menegus MA
J Pediatr. 1985;107(6):855-860
DOI: [10.1016/s0022-3476(85)80175-x](https://doi.org/10.1016/s0022-3476(85)80175-x)

## Worked example

### All Dagan 1985 low-risk criteria met

Given: `abc_ul=200, age_days=45, diarrhea=false, no_focal_infection=true, previously_healthy=true, ua_wbc_le_10=true, wbc_k_ul=8.0, well_appearing=true`

1. age_days 45 < 90 (younger than 3 months)
2. previously_healthy, well_appearing, and no_focal_infection are true
3. WBC 8.0 k/µL = 8000/mm^3 is between 5000 and 15000 inclusive; abc_ul 200 < 1500; ua_wbc_le_10 true; no diarrhea so stool is not required
4. Every criterion holds, so low_risk is true


## Also searched as

- Rochester criteria
- Rochester febrile infant
- Dagan 1985
- Rochester suspected sepsis
- febrile infant low risk
- Rochester criteria infants
- Dagan Powell Hall Menegus
- infant serious bacterial infection rule

## Parameters

- `age_days` (integer, required): Chronological age in days (integer 0-90). Dagan 1985 studied infants younger than 3 months; low-risk requires age_days < 90 (0-89). 90 is accepted but is not low-risk.
- `previously_healthy` (boolean, required): Previously healthy as in Dagan 1985: born at term, no perinatal complications, no previous or underlying disease, and no previous antibiotic therapy. true or false as assigned by the caller. magent does not take a birth history.
- `well_appearing` (boolean, required): Well appearing / not ill appearing as assigned by the caller. true or false. magent does not examine the infant.
- `no_focal_infection` (boolean, required): No physical findings consistent with ear, soft tissue, or skeletal infection (Dagan 1985). true means none of those foci are present. true or false as assigned by the caller. magent does not examine the infant.
- `wbc_k_ul` (number, optional): Peripheral WBC in 10^3/µL (same as 10^9/L or 10^3/mm^3). Provide wbc_k_ul or wbc_ul. Range 0.01-500. Low-risk requires 5.0-15.0 inclusive (5000-15000/mm^3; 5.0 and 15.0 meet; 4.99 and 15.01 do not).
- `wbc_ul` (number, optional): Peripheral WBC in cells/µL (same as cells/mm^3). Provide wbc_k_ul or wbc_ul. Range 10-500000. Low-risk requires 5000-15000 inclusive (5000 and 15000 meet; 4999 and 15001 do not).
- `abc_ul` (number, required): Absolute band count in cells/µL (same as bands/mm^3). Range 0-100000. Dagan 1985 low-risk requires less than 1500 (1499 meets; 1500 does not).
- `ua_wbc_le_10` (boolean, required): Urinalysis ≤10 WBC/hpf (normal urine findings as used with Dagan 1985 Rochester). true or false as assigned by the caller. magent does not read the sediment.
- `diarrhea` (boolean, required): Diarrhea is present. true or false as assigned by the caller. When true, stool_wbc_le_5 is required. When false, the stool criterion holds without a stool smear.
- `stool_wbc_le_5` (boolean, optional): Stool ≤5 WBC/hpf. Required when diarrhea is true. true or false as assigned by the caller. Ignored when diarrhea is false. magent does not read the smear.

## Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/rochester`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
- The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
- HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
- Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
- x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request:

```json
{
  "items": [
    {
      "abc_ul": "200",
      "age_days": "45",
      "diarrhea": "false",
      "no_focal_infection": "true",
      "previously_healthy": "true",
      "ua_wbc_le_10": "true",
      "wbc_k_ul": "8.0",
      "well_appearing": "true"
    },
    {
      "abc_ul": "200",
      "age_days": "45",
      "diarrhea": "false",
      "no_focal_infection": "true",
      "previously_healthy": "true",
      "ua_wbc_le_10": "true",
      "wbc_k_ul": "8.0",
      "well_appearing": "true"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/rochester

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/rochester",
  "items": [
    {
      "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.",
      "citation": {
        "authors": "Dagan R, Powell KR, Hall CB, Menegus MA",
        "doi": "10.1016/s0022-3476(85)80175-x",
        "id": "dagan-1985",
        "pmid": "4067741",
        "source": "J Pediatr. 1985;107(6):855-860",
        "title": "Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis"
      },
      "formula": "rochester",
      "formula_expression": "low_risk iff age_days < 90 and previously_healthy and well_appearing and no_focal_infection and 5000 <= wbc_ul <= 15000 and abc_ul < 1500 and ua_wbc_le_10 and (not diarrhea or stool_wbc_le_5) (Dagan 1985)",
      "criteria": [
        {
          "value": 45,
          "factor": "age_lt_90",
          "met": true
        },
        {
          "factor": "previously_healthy",
          "met": true
        },
        {
          "factor": "well_appearing",
          "met": true
        },
        {
          "factor": "no_focal_infection",
          "met": true
        },
        {
          "value": 8.0e3,
          "factor": "wbc_5_to_15",
          "met": true
        },
        {
          "value": 200.0,
          "factor": "abc_lt_1500",
          "met": true
        },
        {
          "factor": "ua_wbc_le_10",
          "met": true
        },
        {
          "factor": "stool_ok",
          "met": true
        }
      ],
      "wbc_ul": 8.0e3,
      "low_risk": true,
      "abc_ul": 200.0,
      "age_days": 45
    },
    {
      "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.",
      "citation": {
        "authors": "Dagan R, Powell KR, Hall CB, Menegus MA",
        "doi": "10.1016/s0022-3476(85)80175-x",
        "id": "dagan-1985",
        "pmid": "4067741",
        "source": "J Pediatr. 1985;107(6):855-860",
        "title": "Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis"
      },
      "formula": "rochester",
      "formula_expression": "low_risk iff age_days < 90 and previously_healthy and well_appearing and no_focal_infection and 5000 <= wbc_ul <= 15000 and abc_ul < 1500 and ua_wbc_le_10 and (not diarrhea or stool_wbc_le_5) (Dagan 1985)",
      "criteria": [
        {
          "value": 45,
          "factor": "age_lt_90",
          "met": true
        },
        {
          "factor": "previously_healthy",
          "met": true
        },
        {
          "factor": "well_appearing",
          "met": true
        },
        {
          "factor": "no_focal_infection",
          "met": true
        },
        {
          "value": 8.0e3,
          "factor": "wbc_5_to_15",
          "met": true
        },
        {
          "value": 200.0,
          "factor": "abc_lt_1500",
          "met": true
        },
        {
          "factor": "ua_wbc_le_10",
          "met": true
        },
        {
          "factor": "stool_ok",
          "met": true
        }
      ],
      "wbc_ul": 8.0e3,
      "low_risk": true,
      "abc_ul": 200.0,
      "age_days": 45
    }
  ]
}
```

## Response fields

- `formula` (string): rochester
- `formula_expression` (string): Dagan 1985 all-criteria low-risk rule
- `low_risk` (boolean): true only when every Dagan 1985 Rochester low-risk criterion holds. false is not_low_risk. Not an SBI probability and not a discharge order.
- `age_days` (integer): Age in days used for the younger-than-3-months (age_days < 90) criterion
- `wbc_ul` (number): Normalized peripheral WBC in cells/µL used for the 5000-15000 inclusive cutoff
- `abc_ul` (number): Absolute band count in cells/µL used for the <1500 cutoff
- `criteria` (array): Per-criterion rows with factor and met: age_lt_90, previously_healthy, well_appearing, no_focal_infection, wbc_5_to_15, abc_lt_1500, ua_wbc_le_10, stool_ok. low_risk iff all are met.
- `citation` (object): Dagan et al. J Pediatr 1985 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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.",
  "citation": {
    "authors": "Dagan R, Powell KR, Hall CB, Menegus MA",
    "doi": "10.1016/s0022-3476(85)80175-x",
    "id": "dagan-1985",
    "pmid": "4067741",
    "source": "J Pediatr. 1985;107(6):855-860",
    "title": "Identification of infants unlikely to have serious bacterial infection although hospitalized for suspected sepsis"
  },
  "formula": "rochester",
  "formula_expression": "low_risk iff age_days < 90 and previously_healthy and well_appearing and no_focal_infection and 5000 <= wbc_ul <= 15000 and abc_ul < 1500 and ua_wbc_le_10 and (not diarrhea or stool_wbc_le_5) (Dagan 1985)",
  "criteria": [
    {
      "value": 45,
      "factor": "age_lt_90",
      "met": true
    },
    {
      "factor": "previously_healthy",
      "met": true
    },
    {
      "factor": "well_appearing",
      "met": true
    },
    {
      "factor": "no_focal_infection",
      "met": true
    },
    {
      "value": 8.0e3,
      "factor": "wbc_5_to_15",
      "met": true
    },
    {
      "value": 200.0,
      "factor": "abc_lt_1500",
      "met": true
    },
    {
      "factor": "ua_wbc_le_10",
      "met": true
    },
    {
      "factor": "stool_ok",
      "met": true
    }
  ],
  "wbc_ul": 8.0e3,
  "low_risk": true,
  "abc_ul": 200.0,
  "age_days": 45
}
```

## Errors

- HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged.
- HTTP 400 `invalid_rochester`: each Rochester 1985 febrile-infant criterion must be true or false. Returned before settlement; you are not charged.
- HTTP 400 `invalid_age_days`: age_days must be an integer from 0 to 90 (Dagan 1985 Rochester). Returned before settlement; you are not charged.
- HTTP 400 `invalid_wbc`: wbc_k_ul (0.01-500) or wbc_ul (10-500000) is required Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [Bacterial Meningitis Score](https://magentlab.com/docs/bacterial-meningitis) — Sum the Nigrovic 2002 Bacterial Meningitis Score weights for children with CSF pleocytosis and return very_low_risk (0) or not_low_risk (≥1).

## Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/docs/mcp

## Guarantees

- HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
- exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
- HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.