# Cambridge diabetes risk score

Cambridge diabetes

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/cambridge_diabetes`
HTML: https://magentlab.com/docs/cambridge-diabetes
Markdown: https://magentlab.com/docs/cambridge-diabetes.md

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

## What it computes

Compute the Griffin 2000 Cambridge logistic probability of undetected type 2 diabetes from age, sex, BMI, prescribed antihypertensive medication, prescribed steroids, first-degree family history, and smoking.

## When to use

When an agent has those routinely collected Griffin 2000 predictors as assigned by the caller and needs the published logistic probability of undetected type 2 diabetes. Not FINDRISC points, not the ADA risk test, and not a glucose assay.

## When not to use

- Not a medical device. magent does not diagnose type 2 diabetes and does not assay glucose.
- Griffin 2000 logistic model of undetected (prevalent) type 2 diabetes. Not a 10-year incidence model. Not FINDRISC points. Not the ADA diabetes risk test.
- Age is clamped to 40-64 years, the Griffin 2000 derivation range. BMI 10-80 is a magent clamp; magent does not compute BMI from height and weight.
- antihypertensive, steroids, family_history, and smoking are caller-assigned. magent does not read a medication list, take a pedigree, or take a smoking history.
- Returns probability on 0-1. Griffin 2000 does not print a screening cutoff; later papers' 0.11 / 0.15 / 0.37 thresholds are not this tool.
- Intercept is -6.322 as published. magent does not invert the sign of the intercept.

## Formula

```
p = 1/(1+e^(-λ)); λ = -6.322 -0.879*(sex=female) + 1.222*antihypertensive + 2.191*steroids + 0.063*age + bmi + family + smoking; BMI <25 -> 0, >=25 and <27.5 -> 0.699, >=27.5 and <30 -> 1.97, >=30 -> 2.518; family none 0, parent_or_sibling 0.728, parent_and_sibling 0.753; smoking never 0, former -0.218, current 0.855; Griffin 2000 logistic risk of undetected type 2 diabetes; age 40-64
```

## Citation

[Diabetes risk score: towards earlier detection of type 2 diabetes in general practice](https://doi.org/10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R)
Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ
Diabetes Metab Res Rev. 2000;16(3):164-171
DOI: [10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R](https://doi.org/10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R)

## Worked example

### 50-year-old male, BMI 24, no meds, no family history, never smoker

Given: `age=50, antihypertensive=false, bmi_kg_m2=24, family_history=none, sex=male, smoking=never, steroids=false`

1. Male 0; BMI 24 <25 -> 0; antihypertensive false 0; steroids false 0; family none 0; smoking never 0
2. λ = -6.322 + 0.063×50 = -3.172
3. p = 1/(1+e^(3.172)) = 0.0402


## Also searched as

- Cambridge diabetes risk score
- Griffin diabetes risk score
- Cambridge Risk Score
- undetected type 2 diabetes score
- Griffin 2000 diabetes score
- Cambridge diabetes
- CRS type 2 diabetes

## Parameters

- `age` (integer, required): Age in years. Griffin 2000 derivation was ages 40-64; magent accepts that published range only. Continuous linear predictor at 0.063 per year.
- `sex` (string, required): female or male. Griffin 2000 female coefficient is -0.879; male is the reference (0).
- `bmi_kg_m2` (number, required): Body-mass index in kg/m^2 (10-80, magent clamp). Caller-supplied; magent does not compute BMI from height and weight. Griffin 2000: <25 -> 0; >=25 and <27.5 -> 0.699; >=27.5 and <30 -> 1.97; >=30 -> 2.518.
- `antihypertensive` (boolean, required): Prescribed antihypertensive medication as assigned by the caller (Griffin 2000). true adds 1.222; false adds 0. magent does not read a medication list.
- `steroids` (boolean, required): Prescribed steroids as assigned by the caller (Griffin 2000). true adds 2.191; false adds 0. magent does not read a medication list.
- `family_history` (string, required): First-degree family history of diabetes (Griffin 2000). none 0; parent_or_sibling 0.728 (parent or sibling, not both); parent_and_sibling 0.753 (parent and sibling). magent does not take a pedigree.
- `smoking` (string, required): Smoking history (Griffin 2000). never (nonsmoker) 0; former (ex-smoker) -0.218; current 0.855. magent does not take a smoking history.

## 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/cambridge_diabetes`
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": [
    {
      "age": "50",
      "antihypertensive": "false",
      "bmi_kg_m2": "24",
      "family_history": "none",
      "sex": "male",
      "smoking": "never",
      "steroids": "false"
    },
    {
      "age": "50",
      "antihypertensive": "false",
      "bmi_kg_m2": "24",
      "family_history": "none",
      "sex": "male",
      "smoking": "never",
      "steroids": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/cambridge-diabetes

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/cambridge_diabetes",
  "items": [
    {
      "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.",
      "age_years": 50,
      "citation": {
        "authors": "Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ",
        "doi": "10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R",
        "id": "griffin-2000",
        "pmid": "10867715",
        "source": "Diabetes Metab Res Rev. 2000;16(3):164-171",
        "title": "Diabetes risk score: towards earlier detection of type 2 diabetes in general practice"
      },
      "formula": "cambridge_diabetes",
      "formula_expression": "p = 1/(1+e^(-λ)); λ = -6.322 -0.879*(sex=female) + 1.222*antihypertensive + 2.191*steroids + 0.063*age + bmi + family + smoking; BMI <25 -> 0, >=25 and <27.5 -> 0.699, >=27.5 and <30 -> 1.97, >=30 -> 2.518; family none 0, parent_or_sibling 0.728, parent_and_sibling 0.753; smoking never 0, former -0.218, current 0.855; Griffin 2000 logistic risk of undetected type 2 diabetes; age 40-64",
      "sex": "male",
      "antihypertensive": false,
      "bmi_kg_m2": 24.0,
      "family_history": "none",
      "linear_predictor": -3.172,
      "probability": 0.0402,
      "smoking": "never",
      "steroids": 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.",
      "age_years": 50,
      "citation": {
        "authors": "Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ",
        "doi": "10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R",
        "id": "griffin-2000",
        "pmid": "10867715",
        "source": "Diabetes Metab Res Rev. 2000;16(3):164-171",
        "title": "Diabetes risk score: towards earlier detection of type 2 diabetes in general practice"
      },
      "formula": "cambridge_diabetes",
      "formula_expression": "p = 1/(1+e^(-λ)); λ = -6.322 -0.879*(sex=female) + 1.222*antihypertensive + 2.191*steroids + 0.063*age + bmi + family + smoking; BMI <25 -> 0, >=25 and <27.5 -> 0.699, >=27.5 and <30 -> 1.97, >=30 -> 2.518; family none 0, parent_or_sibling 0.728, parent_and_sibling 0.753; smoking never 0, former -0.218, current 0.855; Griffin 2000 logistic risk of undetected type 2 diabetes; age 40-64",
      "sex": "male",
      "antihypertensive": false,
      "bmi_kg_m2": 24.0,
      "family_history": "none",
      "linear_predictor": -3.172,
      "probability": 0.0402,
      "smoking": "never",
      "steroids": false
    }
  ]
}
```

## Response fields

- `formula` (string): cambridge_diabetes
- `formula_expression` (string): Griffin 2000 logistic expression with intercept -6.322
- `age_years` (integer): Age in years used (40-64)
- `sex` (string): female or male used
- `bmi_kg_m2` (number): Caller-supplied BMI in kg/m^2 used for the BMI band
- `antihypertensive` (boolean): Caller-assigned prescribed antihypertensive medication
- `steroids` (boolean): Caller-assigned prescribed steroids
- `family_history` (string): none, parent_or_sibling, or parent_and_sibling
- `smoking` (string): never, former, or current
- `linear_predictor` (number): Griffin 2000 λ (intercept -6.322), 4 decimals
- `probability` (number): p = 1/(1+e^(-λ)) on 0-1, 4 decimals. Logistic risk of undetected type 2 diabetes. Not a screening cutoff and not a diagnosis.
- `citation` (object): Griffin 2000 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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.",
  "age_years": 50,
  "citation": {
    "authors": "Griffin SJ, Little PS, Hales CN, Kinmonth AL, Wareham NJ",
    "doi": "10.1002/1520-7560(200005/06)16:3<164::AID-DMRR103>3.0.CO;2-R",
    "id": "griffin-2000",
    "pmid": "10867715",
    "source": "Diabetes Metab Res Rev. 2000;16(3):164-171",
    "title": "Diabetes risk score: towards earlier detection of type 2 diabetes in general practice"
  },
  "formula": "cambridge_diabetes",
  "formula_expression": "p = 1/(1+e^(-λ)); λ = -6.322 -0.879*(sex=female) + 1.222*antihypertensive + 2.191*steroids + 0.063*age + bmi + family + smoking; BMI <25 -> 0, >=25 and <27.5 -> 0.699, >=27.5 and <30 -> 1.97, >=30 -> 2.518; family none 0, parent_or_sibling 0.728, parent_and_sibling 0.753; smoking never 0, former -0.218, current 0.855; Griffin 2000 logistic risk of undetected type 2 diabetes; age 40-64",
  "sex": "male",
  "antihypertensive": false,
  "bmi_kg_m2": 24.0,
  "family_history": "none",
  "linear_predictor": -3.172,
  "probability": 0.0402,
  "smoking": "never",
  "steroids": false
}
```

## Errors

- HTTP 400 `invalid_cambridge_diabetes`: Cambridge diabetes risk inputs must match Griffin 2000 age, sex, BMI, medications, family history, and smoking. 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

- [FINDRISC](https://magentlab.com/docs/findrisc) — Sum the original Lindström 2003 seven-item Finnish diabetes risk score (FINDRISC, 0–20) and return at_risk when the total is ≥9.
- [METS-IR](https://magentlab.com/docs/mets-ir) — Compute the Bello-Chavolla 2018 METS-IR score from fasting glucose, triglycerides, caller-supplied BMI, and HDL as a marker of insulin sensitivity associated with visceral adiposity and incident type 2 diabetes.
- [HOMA-IR](https://magentlab.com/docs/homa-ir) — Compute the Matthews 1985 HOMA-IR approximation from fasting plasma glucose and insulin.

## 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.