# MUST malnutrition screening MUST Status: LIVE Price: $0.005 USDC `GET /api/calc/must` HTML: https://magentlab.com/docs/must Markdown: https://magentlab.com/docs/must.md 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 [Malnutrition in hospital outpatients and inpatients: prevalence, concurrent validity and ease of use of the 'malnutrition universal screening tool' ('MUST') for adults](https://doi.org/10.1079/BJN20041258) Stratton RJ, Hackston A, Longmore D, Dixon R, Price S, Stroud M, King C, Elia M Br J Nutr. 2004;92(5):799-808 DOI: [10.1079/BJN20041258](https://doi.org/10.1079/BJN20041258) ## Worked example ### All 0-point bands (low risk) Given: `acute_disease_no_intake_gt_5_days=false, bmi_kg_m2=22, weight_loss_percent=0` 1. BMI 22 >20 → 0; unplanned weight loss 0% <5 → 0; acute disease false → 0 2. Score = 0 (published max 6); risk low ### Maximum 6 (high risk) Given: `acute_disease_no_intake_gt_5_days=true, bmi_kg_m2=17, weight_loss_percent=12` 1. BMI 17 <18.5 → 2; unplanned weight loss 12% >10 → 2; acute disease true → 2 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 ## Parameters - `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. Method: `POST /api/calc/must` 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": [ { "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" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/must Example 200: ```json { "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 fields - `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 Frozen fixture. Not a live lookup. ```json { "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 } ``` ## Errors - HTTP 400 `invalid_bmi_kg_m2`: bmi_kg_m2 must be a number from 10 to 80. Returned before settlement; you are not charged. - HTTP 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. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false 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 - [NRI](https://magentlab.com/docs/nri) — Apply the VA TPN Cooperative Study 1991 Nutritional Risk Index from caller-supplied albumin and current/usual weight. - [NRS-2002](https://magentlab.com/docs/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](https://magentlab.com/docs/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. - 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.