Emergency · LIVE

Obesity surgery mortality risk score (OS-MRS)

OS-MRS

Sum the five DeMaria 2007 obesity surgery mortality risk score flags and return class A–C.

LIVE $0.005 USDC GET /api/calc/os_mrs

Markdown: /docs/os-mrs.md · Canonical: https://magentlab.com/docs/os-mrs

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

What it computes

Sum the five DeMaria 2007 obesity surgery mortality risk score flags and return class A–C.

When to use

When an agent needs the published OS-MRS point total and DeMaria 2007 class and must not invent a surgical-clearance decision or a mortality percentage.

When not to use

• Not a medical device.
• Not a surgical clearance, cancellation, or monitoring order.
• Not a mortality percentage. Class A–C is the published DeMaria 2007 grouping, not a probability.
• magent does not weigh the patient and does not measure BMI or age. Each flag is caller-assigned.

Formula

OS-MRS = bmi_ge_50 + male + hypertension + pe_risk_factors + age_ge_45; each 1 if true; max 5; class A 0-1, B 2-3, C 4-5

Citation

Title

Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass

Authors

DeMaria EJ, Portenier D, Wolfe L

Source

Surg Obes Relat Dis. 2007;3(2):134-140

DOI

10.1016/j.soard.2007.01.005

Worked example

Also searched as

• OS-MRS
• obesity surgery mortality risk score
• DeMaria OS-MRS
• OSMRS
• bariatric mortality risk score
• gastric bypass mortality score
• DeMaria 2007

Try

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

/api/calc/os_mrs?bmi_ge_50=false&male=false&hypertension=false&pe_risk_factors=false&age_ge_45=false

Full URL: https://api.magentlab.com/api/calc/os_mrs?bmi_ge_50=false&male=false&hypertension=false&pe_risk_factors=false&age_ge_45=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/os_mrs?bmi_ge_50=false&male=false&hypertension=false&pe_risk_factors=false&age_ge_45=false"

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/os_mrs 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": [
    {
      "age_ge_45": "false",
      "bmi_ge_50": "false",
      "hypertension": "false",
      "male": "false",
      "pe_risk_factors": "false"
    },
    {
      "age_ge_45": "false",
      "bmi_ge_50": "false",
      "hypertension": "false",
      "male": "false",
      "pe_risk_factors": "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/os_mrs",
  "items": [
    {
      "class": "A",
      "components": [
        {
          "factor": "bmi_ge_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "male",
          "points": 0,
          "present": false
        },
        {
          "factor": "hypertension",
          "points": 0,
          "present": false
        },
        {
          "factor": "pe_risk_factors",
          "points": 0,
          "present": false
        },
        {
          "factor": "age_ge_45",
          "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": "DeMaria EJ, Portenier D, Wolfe L",
        "doi": "10.1016/j.soard.2007.01.005",
        "id": "demaria-2007",
        "pmid": "17386394",
        "source": "Surg Obes Relat Dis. 2007;3(2):134-140",
        "title": "Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass"
      },
      "formula": "os_mrs",
      "formula_expression": "OS-MRS = bmi_ge_50 + male + hypertension + pe_risk_factors + age_ge_45; each 1 if true; max 5; class A 0-1, B 2-3, C 4-5",
      "max_score": 5,
      "score": 0
    },
    {
      "class": "A",
      "components": [
        {
          "factor": "bmi_ge_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "male",
          "points": 0,
          "present": false
        },
        {
          "factor": "hypertension",
          "points": 0,
          "present": false
        },
        {
          "factor": "pe_risk_factors",
          "points": 0,
          "present": false
        },
        {
          "factor": "age_ge_45",
          "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": "DeMaria EJ, Portenier D, Wolfe L",
        "doi": "10.1016/j.soard.2007.01.005",
        "id": "demaria-2007",
        "pmid": "17386394",
        "source": "Surg Obes Relat Dis. 2007;3(2):134-140",
        "title": "Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass"
      },
      "formula": "os_mrs",
      "formula_expression": "OS-MRS = bmi_ge_50 + male + hypertension + pe_risk_factors + age_ge_45; each 1 if true; max 5; class A 0-1, B 2-3, C 4-5",
      "max_score": 5,
      "score": 0
    }
  ]
}

Response

Example JSON

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

{
  "class": "A",
  "components": [
    {
      "factor": "bmi_ge_50",
      "points": 0,
      "present": false
    },
    {
      "factor": "male",
      "points": 0,
      "present": false
    },
    {
      "factor": "hypertension",
      "points": 0,
      "present": false
    },
    {
      "factor": "pe_risk_factors",
      "points": 0,
      "present": false
    },
    {
      "factor": "age_ge_45",
      "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": "DeMaria EJ, Portenier D, Wolfe L",
    "doi": "10.1016/j.soard.2007.01.005",
    "id": "demaria-2007",
    "pmid": "17386394",
    "source": "Surg Obes Relat Dis. 2007;3(2):134-140",
    "title": "Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass"
  },
  "formula": "os_mrs",
  "formula_expression": "OS-MRS = bmi_ge_50 + male + hypertension + pe_risk_factors + age_ge_45; each 1 if true; max 5; class A 0-1, B 2-3, C 4-5",
  "max_score": 5,
  "score": 0
}

Client errors (HTTP 400)

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

Related tools

• RCRI — Sum the six Lee 1999 revised cardiac risk index factors and return class I–IV.
• Gupta MICA — Compute the Gupta 2011 Table 2 logistic probability of 30-day myocardial infarction or cardiac arrest after surgery from age, ASA class, functional status, creatinine category, and surgery type.
• Surgical Apgar — Compute the Gawande 2007 intraoperative Surgical Apgar score from estimated blood loss, lowest mean arterial pressure, and lowest heart rate.

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.