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BARD score (Harrison 2008)

BARD

Sum the Harrison 2008 BARD score (BMI ≥28, AST/ALT ≥0.8, diabetes) and return low (0–1) or high (2–4).

LIVE $0.005 USDC GET /api/calc/bard

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

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

What it computes

Sum the Harrison 2008 BARD score (BMI ≥28, AST/ALT ≥0.8, diabetes) and return low (0–1) or high (2–4).

When to use

When an agent has caller-supplied BMI, AST, ALT, and a diabetes flag for a patient already recognized as NAFLD and needs the published BARD total, not a NASH diagnosis, biopsy stage, FIB-4, APRI, or NAFLD fibrosis score.

When not to use

Not a medical device and not a NASH diagnosis. magent does not interpret a biopsy.
BMI is caller-supplied. magent does not compute BMI from height and weight in this tool.
Harrison 2008 BARD only: BMI ≥28 (1), AST/ALT ≥0.8 (2), diabetes mellitus (1). Max 4. risk_group is the paper's 2–4 vs 0–1 split (low 0–1, high 2–4), not F0–F4 stages.
A score of 2–4 was associated with OR 17 for advanced fibrosis and NPV 96% in Harrison 2008. NPV is not a biopsy result.
Not the NAFLD fibrosis score, not FIB-4, and not APRI.

Formula

BARD = 1 if BMI >= 28 + 2 if AST/ALT >= 0.8 + 1 if diabetes; Harrison 2008; max 4; risk_group low 0-1, high 2-4. Not a biopsy. Not F0-F4.

Citation

Title: Development and validation of a simple NAFLD clinical scoring system for identifying patients without advanced disease
Authors: Harrison SA, Oliver D, Arnold HL, Gogia S, Neuschwander-Tetri BA
Source: Gut. 2008;57(10):1441-1447
DOI: 10.1136/gut.2007.146019

Worked example

BMI 25, AST 20, ALT 40, no diabetes

Given: alt_u_l=40ast_u_l=20bmi=25diabetes=false

BMI 25 < 28 → 0; AAR = 20/40 = 0.5 < 0.8 → 0; diabetes false → 0
Score = 0 (max 4); risk_group = low

Also searched as

BARD score
Harrison BARD
NAFLD BARD
BMI AST ALT diabetes score
BARD fibrosis
Harrison 2008 BARD
AST ALT ratio BARD
NAFLD advanced fibrosis BARD

Try

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

/api/calc/bard?bmi=25&ast_u_l=20&alt_u_l=40&diabetes=false

Full URL: https://api.magentlab.com/api/calc/bard?bmi=25&ast_u_l=20&alt_u_l=40&diabetes=false

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/bard?bmi=25&ast_u_l=20&alt_u_l=40&diabetes=false"

Parameters

Name	Type	Required	Description
`bmi`	number	required	Body-mass index in kg/m^2 (10-80). >=28 scores 1 (Harrison 2008). 27.9 scores 0. Caller-supplied; magent does not compute BMI from height and weight.
`ast_u_l`	number	required	Aspartate aminotransferase in U/L (1-10000). Used with ALT for the AAR.
`alt_u_l`	number	required	Alanine aminotransferase in U/L (1-10000). AST/ALT >= 0.8 scores 2 (Harrison 2008). 0.799 scores 0. ALT must be >0.
`diabetes`	boolean	required	Diabetes mellitus as assigned by the caller (Harrison 2008). true scores 1. magent does not diagnose diabetes.

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/bard 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": [
    {
      "alt_u_l": "40",
      "ast_u_l": "20",
      "bmi": "25",
      "diabetes": "false"
    },
    {
      "alt_u_l": "40",
      "ast_u_l": "20",
      "bmi": "25",
      "diabetes": "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/bard",
  "items": [
    {
      "components": [
        {
          "value": 25.0,
          "factor": "bmi_ge_28",
          "points": 0,
          "present": false
        },
        {
          "value": 0.5,
          "factor": "ast_alt_ratio_ge_0_8",
          "points": 0,
          "present": false
        },
        {
          "factor": "diabetes",
          "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": "Harrison SA, Oliver D, Arnold HL, Gogia S, Neuschwander-Tetri BA",
        "doi": "10.1136/gut.2007.146019",
        "id": "harrison-2008",
        "pmid": "18390575",
        "source": "Gut. 2008;57(10):1441-1447",
        "title": "Development and validation of a simple NAFLD clinical scoring system for identifying patients without advanced disease"
      },
      "formula": "bard",
      "formula_expression": "BARD = 1 if BMI >= 28 + 2 if AST/ALT >= 0.8 + 1 if diabetes; Harrison 2008; max 4; risk_group low 0-1, high 2-4. Not a biopsy. Not F0-F4.",
      "max_score": 4,
      "score": 0,
      "ast_u_l": 20.0,
      "bmi": 25.0,
      "alt_u_l": 40.0,
      "ast_alt_ratio": 0.5,
      "diabetes": false,
      "risk_group": "low"
    },
    {
      "components": [
        {
          "value": 25.0,
          "factor": "bmi_ge_28",
          "points": 0,
          "present": false
        },
        {
          "value": 0.5,
          "factor": "ast_alt_ratio_ge_0_8",
          "points": 0,
          "present": false
        },
        {
          "factor": "diabetes",
          "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": "Harrison SA, Oliver D, Arnold HL, Gogia S, Neuschwander-Tetri BA",
        "doi": "10.1136/gut.2007.146019",
        "id": "harrison-2008",
        "pmid": "18390575",
        "source": "Gut. 2008;57(10):1441-1447",
        "title": "Development and validation of a simple NAFLD clinical scoring system for identifying patients without advanced disease"
      },
      "formula": "bard",
      "formula_expression": "BARD = 1 if BMI >= 28 + 2 if AST/ALT >= 0.8 + 1 if diabetes; Harrison 2008; max 4; risk_group low 0-1, high 2-4. Not a biopsy. Not F0-F4.",
      "max_score": 4,
      "score": 0,
      "ast_u_l": 20.0,
      "bmi": 25.0,
      "alt_u_l": 40.0,
      "ast_alt_ratio": 0.5,
      "diabetes": false,
      "risk_group": "low"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	bard
`formula_expression`	string	Exact expression used
`score`	integer	BARD points 0-4
`max_score`	integer	Always 4 (1+2+1)
`risk_group`	string	low when score is 0-1, high when 2-4 (Harrison 2008 2-4 vs 0-1 split). Not F0-F4. Not a NASH diagnosis. magent does not interpret a biopsy.
`bmi`	number	Caller-supplied BMI in kg/m^2
`ast_u_l`	number	AST in U/L
`alt_u_l`	number	ALT in U/L
`ast_alt_ratio`	number	AST/ALT ratio (AAR), 4 decimals
`diabetes`	boolean	Caller-assigned diabetes flag used
`components`	array	Per-factor points
`citation`	object	Harrison Gut 2008 citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": 25.0,
      "factor": "bmi_ge_28",
      "points": 0,
      "present": false
    },
    {
      "value": 0.5,
      "factor": "ast_alt_ratio_ge_0_8",
      "points": 0,
      "present": false
    },
    {
      "factor": "diabetes",
      "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": "Harrison SA, Oliver D, Arnold HL, Gogia S, Neuschwander-Tetri BA",
    "doi": "10.1136/gut.2007.146019",
    "id": "harrison-2008",
    "pmid": "18390575",
    "source": "Gut. 2008;57(10):1441-1447",
    "title": "Development and validation of a simple NAFLD clinical scoring system for identifying patients without advanced disease"
  },
  "formula": "bard",
  "formula_expression": "BARD = 1 if BMI >= 28 + 2 if AST/ALT >= 0.8 + 1 if diabetes; Harrison 2008; max 4; risk_group low 0-1, high 2-4. Not a biopsy. Not F0-F4.",
  "max_score": 4,
  "score": 0,
  "ast_u_l": 20.0,
  "bmi": 25.0,
  "alt_u_l": 40.0,
  "ast_alt_ratio": 0.5,
  "diabetes": false,
  "risk_group": "low"
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_bard`	bmi 10-80, ast_u_l 1-10000, and alt_u_l 1-10000 (Harrison 2008; magent clamps). Returned before settlement; you are not charged.
400	`invalid_flag`	boolean clinical flags must be true or false Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

NAFLD fibrosis score — Compute the Angulo 2007 NAFLD fibrosis score from age, BMI, IFG/diabetes, AST, ALT, platelets, and albumin.

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.