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NIVO score (Hartley 2021)

NIVO

Sum Hartley 2021 NIVO points from chest radiograph consolidation, GCS ≤14, atrial fibrillation, pH <7.25, time to acidaemia >12 h, and eMRCD, and return the validation Table 4 grouped in-hospital mortality band.

LIVE $0.005 USDC GET /api/calc/nivo

Markdown: /docs/nivo.md · Canonical: https://magentlab.com/docs/nivo

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

What it computes

Sum Hartley 2021 NIVO points from chest radiograph consolidation, GCS ≤14, atrial fibrillation, pH <7.25, time to acidaemia >12 h, and eMRCD, and return the validation Table 4 grouped in-hospital mortality band.

When to use

When an agent needs the published Hartley 2021 NIVO total and Table 4 grouped band for AECOPD with acidaemic hypercapnic respiratory failure treated with assisted ventilation, and must not invent HACOR, DECAF, APACHE II, a weaning prediction, or a per-integer mortality percent.

When not to use

• Not a medical device. Not an intubation, NIV-failure, weaning, or escalation order. Not HACOR, DECAF, or APACHE II.
• Flags and eMRCD are caller-assigned. magent does not interpret the chest radiograph, measure GCS, interpret the ECG, measure arterial pH, or clock time from hospital arrival.
• In-hospital mortality percents are Hartley 2021 validation Table 4 grouped bands only (0–2 / 3–4 / 5–6 / 7–9: 5.0 / 16.8 / 41.2 / 71.4). Per-integer percents are not attached.
• eMRCD 5a and 5b are mutually exclusive; maximum score is 9.

Formula

NIVO = chest_radiograph_consolidation + gcs_le_14 + atrial_fibrillation + ph_lt_7_25 + time_to_acidaemia_gt_12h + emrcd; consolidation true -> 1; GCS <=14 prior to ventilation -> 1; AF (persistent, new, or paroxysmal even if sinus at NIV start) true -> 1; pH <7.25 -> 1; time from hospital arrival to index acidaemia >12 h -> 2; eMRCD 1_to_4 -> 0, 5a -> 2, 5b -> 3; cannot score both 5a and 5b; Hartley 2021 validation Table 4 bands 0-2 / 3-4 / 5-6 / 7-9; max 9

Citation

Title

The Noninvasive Ventilation Outcomes (NIVO) score: prediction of in-hospital mortality in exacerbations of COPD requiring assisted ventilation

Authors

Hartley T, Lane ND, Steer J, et al.

Source

Eur Respir J. 2021;58(2):2004042

DOI

10.1183/13993003.04042-2020

Worked example

Also searched as

• NIVO score
• noninvasive ventilation outcomes
• Hartley NIVO
• COPD NIV mortality
• eMRCD ventilation score
• AECOPD assisted ventilation
• NIVO Hartley 2021

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/nivo?chest_radiograph_consolidation=false&gcs_le_14=false&atrial_fibrillation=false&ph_lt_7_25=false&time_to_acidaemia_gt_12h=false&emrcd=1_to_4

Full URL: https://api.magentlab.com/api/calc/nivo?chest_radiograph_consolidation=false&gcs_le_14=false&atrial_fibrillation=false&ph_lt_7_25=false&time_to_acidaemia_gt_12h=false&emrcd=1_to_4

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/nivo?chest_radiograph_consolidation=false&gcs_le_14=false&atrial_fibrillation=false&ph_lt_7_25=false&time_to_acidaemia_gt_12h=false&emrcd=1_to_4"

Parameters

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.

POST /api/calc/nivo Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 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 (fixture)

{
  "items": [
    {
      "atrial_fibrillation": "false",
      "chest_radiograph_consolidation": "false",
      "emrcd": "1_to_4",
      "gcs_le_14": "false",
      "ph_lt_7_25": "false",
      "time_to_acidaemia_gt_12h": "false"
    },
    {
      "atrial_fibrillation": "false",
      "chest_radiograph_consolidation": "false",
      "emrcd": "1_to_4",
      "gcs_le_14": "false",
      "ph_lt_7_25": "false",
      "time_to_acidaemia_gt_12h": "false"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/nivo",
  "items": [
    {
      "components": [
        {
          "factor": "chest_radiograph_consolidation",
          "points": 0,
          "present": false
        },
        {
          "factor": "gcs_le_14",
          "points": 0,
          "present": false
        },
        {
          "factor": "atrial_fibrillation",
          "points": 0,
          "present": false
        },
        {
          "factor": "ph_lt_7_25",
          "points": 0,
          "present": false
        },
        {
          "factor": "time_to_acidaemia_gt_12h",
          "points": 0,
          "present": false
        },
        {
          "value": "1_to_4",
          "factor": "emrcd",
          "points": 0,
          "present": false
        }
      ],
      "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": "Hartley T, Lane ND, Steer J, et al.",
        "doi": "10.1183/13993003.04042-2020",
        "id": "hartley-2021",
        "pmid": "33479109",
        "source": "Eur Respir J. 2021;58(2):2004042",
        "title": "The Noninvasive Ventilation Outcomes (NIVO) score: prediction of in-hospital mortality in exacerbations of COPD requiring assisted ventilation"
      },
      "formula": "nivo",
      "formula_expression": "NIVO = chest_radiograph_consolidation + gcs_le_14 + atrial_fibrillation + ph_lt_7_25 + time_to_acidaemia_gt_12h + emrcd; consolidation true -> 1; GCS <=14 prior to ventilation -> 1; AF (persistent, new, or paroxysmal even if sinus at NIV start) true -> 1; pH <7.25 -> 1; time from hospital arrival to index acidaemia >12 h -> 2; eMRCD 1_to_4 -> 0, 5a -> 2, 5b -> 3; cannot score both 5a and 5b; Hartley 2021 validation Table 4 bands 0-2 / 3-4 / 5-6 / 7-9; max 9",
      "max_score": 9,
      "score": 0,
      "atrial_fibrillation": false,
      "emrcd": "1_to_4",
      "chest_radiograph_consolidation": false,
      "gcs_le_14": false,
      "in_hospital_mortality_percent": 5.0,
      "nivo_band": "0_to_2",
      "ph_lt_7_25": false,
      "time_to_acidaemia_gt_12h": false
    },
    {
      "components": [
        {
          "factor": "chest_radiograph_consolidation",
          "points": 0,
          "present": false
        },
        {
          "factor": "gcs_le_14",
          "points": 0,
          "present": false
        },
        {
          "factor": "atrial_fibrillation",
          "points": 0,
          "present": false
        },
        {
          "factor": "ph_lt_7_25",
          "points": 0,
          "present": false
        },
        {
          "factor": "time_to_acidaemia_gt_12h",
          "points": 0,
          "present": false
        },
        {
          "value": "1_to_4",
          "factor": "emrcd",
          "points": 0,
          "present": false
        }
      ],
      "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": "Hartley T, Lane ND, Steer J, et al.",
        "doi": "10.1183/13993003.04042-2020",
        "id": "hartley-2021",
        "pmid": "33479109",
        "source": "Eur Respir J. 2021;58(2):2004042",
        "title": "The Noninvasive Ventilation Outcomes (NIVO) score: prediction of in-hospital mortality in exacerbations of COPD requiring assisted ventilation"
      },
      "formula": "nivo",
      "formula_expression": "NIVO = chest_radiograph_consolidation + gcs_le_14 + atrial_fibrillation + ph_lt_7_25 + time_to_acidaemia_gt_12h + emrcd; consolidation true -> 1; GCS <=14 prior to ventilation -> 1; AF (persistent, new, or paroxysmal even if sinus at NIV start) true -> 1; pH <7.25 -> 1; time from hospital arrival to index acidaemia >12 h -> 2; eMRCD 1_to_4 -> 0, 5a -> 2, 5b -> 3; cannot score both 5a and 5b; Hartley 2021 validation Table 4 bands 0-2 / 3-4 / 5-6 / 7-9; max 9",
      "max_score": 9,
      "score": 0,
      "atrial_fibrillation": false,
      "emrcd": "1_to_4",
      "chest_radiograph_consolidation": false,
      "gcs_le_14": false,
      "in_hospital_mortality_percent": 5.0,
      "nivo_band": "0_to_2",
      "ph_lt_7_25": false,
      "time_to_acidaemia_gt_12h": false
    }
  ]
}

Response

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "factor": "chest_radiograph_consolidation",
      "points": 0,
      "present": false
    },
    {
      "factor": "gcs_le_14",
      "points": 0,
      "present": false
    },
    {
      "factor": "atrial_fibrillation",
      "points": 0,
      "present": false
    },
    {
      "factor": "ph_lt_7_25",
      "points": 0,
      "present": false
    },
    {
      "factor": "time_to_acidaemia_gt_12h",
      "points": 0,
      "present": false
    },
    {
      "value": "1_to_4",
      "factor": "emrcd",
      "points": 0,
      "present": false
    }
  ],
  "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": "Hartley T, Lane ND, Steer J, et al.",
    "doi": "10.1183/13993003.04042-2020",
    "id": "hartley-2021",
    "pmid": "33479109",
    "source": "Eur Respir J. 2021;58(2):2004042",
    "title": "The Noninvasive Ventilation Outcomes (NIVO) score: prediction of in-hospital mortality in exacerbations of COPD requiring assisted ventilation"
  },
  "formula": "nivo",
  "formula_expression": "NIVO = chest_radiograph_consolidation + gcs_le_14 + atrial_fibrillation + ph_lt_7_25 + time_to_acidaemia_gt_12h + emrcd; consolidation true -> 1; GCS <=14 prior to ventilation -> 1; AF (persistent, new, or paroxysmal even if sinus at NIV start) true -> 1; pH <7.25 -> 1; time from hospital arrival to index acidaemia >12 h -> 2; eMRCD 1_to_4 -> 0, 5a -> 2, 5b -> 3; cannot score both 5a and 5b; Hartley 2021 validation Table 4 bands 0-2 / 3-4 / 5-6 / 7-9; max 9",
  "max_score": 9,
  "score": 0,
  "atrial_fibrillation": false,
  "emrcd": "1_to_4",
  "chest_radiograph_consolidation": false,
  "gcs_le_14": false,
  "in_hospital_mortality_percent": 5.0,
  "nivo_band": "0_to_2",
  "ph_lt_7_25": false,
  "time_to_acidaemia_gt_12h": false
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

Related tools

• HACOR — Sum Duan 2017 HACOR (ESM Table 2) points from heart rate, pH, GCS, PaO2/FiO2, and respiratory rate and return low (≤5) or high (>5).
• DECAF — Sum Steer 2012 DECAF points from extended MRC dyspnoea, eosinophils, chest radiograph consolidation, arterial pH, and atrial fibrillation.
• BAP-65 — Apply Tabak 2009 BAP-65 and return class I–V from three caller-assigned main factors, using age >65 only to split class I from II when zero main factors are present.
• GOLD spirometric grade — Apply the 2017 GOLD executive summary spirometric classification: obstruction when post-bronchodilator FEV1/FVC is < 0.70, then GOLD grades 1-4 from FEV1 percent predicted.

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. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /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.