MUST malnutrition screening

MUST

Sum Stratton 2004 MUST (BMI, unplanned weight-loss percent, and acute disease with no nutritional intake >5 days) and return score 0–6 with risk low, medium, or high.

LIVE $0.005 USDC GET /api/calc/must

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

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

What it computes

Sum Stratton 2004 MUST (BMI, unplanned weight-loss percent, and acute disease with no nutritional intake >5 days) and return score 0–6 with risk low, medium, or high.

When to use

When an agent has caller-supplied adult BMI and unplanned weight-loss percent and needs the published MUST point total and risk band, not a malnutrition diagnosis, diet order, or MUAC measurement.

When not to use

Not a medical device. Not a malnutrition diagnosis or diet order. magent does not weigh the patient.
Caller supplies BMI (kg/m^2) and unplanned weight-loss percent over 3–6 months. magent does not compute BMI from height and weight.
Adult MUST as in Stratton 2004 (Elia 2003 BAPEN scoring cited therein). Does not use MUAC alternative measurements.
BMI 20.0 scores 1; 20.1 scores 0. Unplanned weight loss 10% scores 1, not 2. Risk is 0 low, 1 medium, ≥2 high.

Formula

MUST = bmi_score + weight_loss_score + acute_disease_score; BMI >20 -> 0, 18.5-20 inclusive -> 1, <18.5 -> 2; unplanned weight loss % last 3-6 months <5 -> 0, 5-10 inclusive -> 1, >10 -> 2; acute disease no nutritional intake >5 days -> 2 else 0; max 6; risk 0 low, 1 medium, >=2 high

Citation

Title: Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'malnutrition universal screening tool' ('MUST') for adults
Authors: Stratton RJ, Hackston A, Longmore D, Dixon R, Price S, Stroud M, King C, Elia M
Source: Br J Nutr. 2004;92(5):799-808
DOI: 10.1079/BJN20041258

Worked example

All 0-point bands (low risk)

Given: acute_disease_no_intake_gt_5_days=falsebmi_kg_m2=22weight_loss_percent=0

BMI 22 >20 → 0; unplanned weight loss 0% <5 → 0; acute disease false → 0
Score = 0 (published max 6); risk low

Maximum 6 (high risk)

Given: acute_disease_no_intake_gt_5_days=truebmi_kg_m2=17weight_loss_percent=12

BMI 17 <18.5 → 2; unplanned weight loss 12% >10 → 2; acute disease true → 2
Score = 6; risk high. Not a diagnosis or diet order.

Also searched as

MUST
Malnutrition Universal Screening Tool
MUST score
BAPEN MUST
malnutrition screening
adult MUST
MUST Stratton 2004

Try

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

/api/calc/must?bmi_kg_m2=22&weight_loss_percent=0&acute_disease_no_intake_gt_5_days=false

Full URL: https://api.magentlab.com/api/calc/must?bmi_kg_m2=22&weight_loss_percent=0&acute_disease_no_intake_gt_5_days=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/must?bmi_kg_m2=22&weight_loss_percent=0&acute_disease_no_intake_gt_5_days=false"

Parameters

Name	Type	Required	Description
`bmi_kg_m2`	number	required	Body-mass index in kg/m^2 (10-80). Caller-supplied; magent does not weigh the patient or compute BMI. Stratton 2004 MUST: >20 scores 0; 18.5-20 inclusive scores 1; <18.5 scores 2. BMI 20.0 scores 1; 20.1 scores 0.
`weight_loss_percent`	number	required	Unplanned weight loss percent over the last 3-6 months (0-50). Caller-supplied; magent does not weigh the patient. Stratton 2004 MUST: <5 scores 0; 5-10 inclusive scores 1; >10 scores 2. 10% scores 1, not 2.
`acute_disease_no_intake_gt_5_days`	boolean	required	Acute disease with no nutritional intake for more than 5 days (Stratton 2004 MUST). true scores 2; false scores 0.

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/must 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": [
    {
      "acute_disease_no_intake_gt_5_days": "false",
      "bmi_kg_m2": "22",
      "weight_loss_percent": "0"
    },
    {
      "acute_disease_no_intake_gt_5_days": "false",
      "bmi_kg_m2": "22",
      "weight_loss_percent": "0"
    }
  ]
}

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/must",
  "items": [
    {
      "components": [
        {
          "value": 22.0,
          "factor": "bmi",
          "points": 0,
          "present": false
        },
        {
          "value": 0.0,
          "factor": "weight_loss",
          "points": 0,
          "present": false
        },
        {
          "factor": "acute_disease",
          "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": "Stratton RJ, Hackston A, Longmore D, Dixon R, Price S, Stroud M, King C, Elia M",
        "doi": "10.1079/BJN20041258",
        "id": "stratton-2004",
        "pmid": "15522139",
        "source": "Br J Nutr. 2004;92(5):799-808",
        "title": "Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'malnutrition universal screening tool' ('MUST') for adults"
      },
      "formula": "must",
      "formula_expression": "MUST = bmi_score + weight_loss_score + acute_disease_score; BMI >20 -> 0, 18.5-20 inclusive -> 1, <18.5 -> 2; unplanned weight loss % last 3-6 months <5 -> 0, 5-10 inclusive -> 1, >10 -> 2; acute disease no nutritional intake >5 days -> 2 else 0; max 6; risk 0 low, 1 medium, >=2 high",
      "max_score": 6,
      "score": 0,
      "bmi_kg_m2": 22.0,
      "risk": "low",
      "acute_disease_score": 0,
      "bmi_score": 0,
      "weight_loss_percent": 0.0,
      "weight_loss_score": 0
    },
    {
      "components": [
        {
          "value": 22.0,
          "factor": "bmi",
          "points": 0,
          "present": false
        },
        {
          "value": 0.0,
          "factor": "weight_loss",
          "points": 0,
          "present": false
        },
        {
          "factor": "acute_disease",
          "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": "Stratton RJ, Hackston A, Longmore D, Dixon R, Price S, Stroud M, King C, Elia M",
        "doi": "10.1079/BJN20041258",
        "id": "stratton-2004",
        "pmid": "15522139",
        "source": "Br J Nutr. 2004;92(5):799-808",
        "title": "Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'malnutrition universal screening tool' ('MUST') for adults"
      },
      "formula": "must",
      "formula_expression": "MUST = bmi_score + weight_loss_score + acute_disease_score; BMI >20 -> 0, 18.5-20 inclusive -> 1, <18.5 -> 2; unplanned weight loss % last 3-6 months <5 -> 0, 5-10 inclusive -> 1, >10 -> 2; acute disease no nutritional intake >5 days -> 2 else 0; max 6; risk 0 low, 1 medium, >=2 high",
      "max_score": 6,
      "score": 0,
      "bmi_kg_m2": 22.0,
      "risk": "low",
      "acute_disease_score": 0,
      "bmi_score": 0,
      "weight_loss_percent": 0.0,
      "weight_loss_score": 0
    }
  ]
}

Response

Field	Type	Description
`formula`	string	must
`formula_expression`	string	Exact Stratton 2004 MUST expression
`score`	integer	MUST points; published range 0-6
`max_score`	integer	6 (Stratton 2004 published maximum)
`bmi_score`	integer	BMI band points: 0 (>20), 1 (18.5-20), or 2 (<18.5)
`weight_loss_score`	integer	Unplanned weight-loss band points: 0 (<5%), 1 (5-10%), or 2 (>10%)
`acute_disease_score`	integer	2 if acute disease with no nutritional intake >5 days, else 0
`risk`	string	low (score 0), medium (score 1), or high (score ≥2). Stratton 2004 / BAPEN screening risk, not a malnutrition diagnosis.
`bmi_kg_m2`	number	Caller-supplied BMI in kg/m^2 used for the BMI band
`weight_loss_percent`	number	Caller-supplied unplanned weight-loss percent used for the weight-loss band
`components`	array	Per-factor points
`citation`	object	Stratton 2004 Br J Nutr citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": 22.0,
      "factor": "bmi",
      "points": 0,
      "present": false
    },
    {
      "value": 0.0,
      "factor": "weight_loss",
      "points": 0,
      "present": false
    },
    {
      "factor": "acute_disease",
      "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": "Stratton RJ, Hackston A, Longmore D, Dixon R, Price S, Stroud M, King C, Elia M",
    "doi": "10.1079/BJN20041258",
    "id": "stratton-2004",
    "pmid": "15522139",
    "source": "Br J Nutr. 2004;92(5):799-808",
    "title": "Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'malnutrition universal screening tool' ('MUST') for adults"
  },
  "formula": "must",
  "formula_expression": "MUST = bmi_score + weight_loss_score + acute_disease_score; BMI >20 -> 0, 18.5-20 inclusive -> 1, <18.5 -> 2; unplanned weight loss % last 3-6 months <5 -> 0, 5-10 inclusive -> 1, >10 -> 2; acute disease no nutritional intake >5 days -> 2 else 0; max 6; risk 0 low, 1 medium, >=2 high",
  "max_score": 6,
  "score": 0,
  "bmi_kg_m2": 22.0,
  "risk": "low",
  "acute_disease_score": 0,
  "bmi_score": 0,
  "weight_loss_percent": 0.0,
  "weight_loss_score": 0
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_bmi_kg_m2`	bmi_kg_m2 must be a number from 10 to 80. Returned before settlement; you are not charged.
400	`invalid_weight_loss_percent`	weight_loss_percent must be a number from 0 to 50 (unplanned percent loss over 3-6 months). 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

NRI — Apply the VA TPN Cooperative Study 1991 Nutritional Risk Index from caller-supplied albumin and current/usual weight.
NRS-2002 — Sum Kondrup 2003 NRS-2002 impaired nutritional status (0–3), disease severity (0–3), and 1 if age ≥70, and return whether the total is at nutritional risk (score ≥3).
NUTRIC — Sum Heyland 2011 original 6-variable NUTRIC (Nutrition Risk in the Critically Ill) Table 4 overall points, including IL-6, and return whether the total is high nutrition risk (score ≥6).

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.