FRACTURE Index with known BMD

FRACTURE Index

Sum the Black 2001 FRACTURE Index with known total-hip BMD T-score from age, T-score, fracture after 50, maternal hip fracture after 50, weight ≤125 lb, current smoking, and arms to stand, then return the integer total and the printed 5-year hip, vertebral, and nonvertebral percents for that quintile.

LIVE $0.005 USDC GET /api/calc/fracture_index

Markdown: /docs/fracture-index.md · Canonical: https://magentlab.com/docs/fracture-index

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

What it computes

When to use

When an agent has caller-supplied age, total-hip T-score, and the five Black 2001 history flags and needs the published with-BMD FRACTURE Index and 5-year percents, not FRAX, not a DXA order, and not a treatment order.

When not to use

Not a medical device. Not a treatment order, DXA order, or osteoporosis diagnosis. magent does not DXA-scan or take a history.
Black 2001 derivation was postmenopausal women in the Study of Osteoporotic Fractures (age 65 or older) with total-hip BMD. That is a limitation, not a sex input. magent does not restrict sex at input.
This tool is the with-known-BMD instrument only. It is not the without-BMD score, not FRAX, not OSTA, not ORAI, and not OSIRIS.
5-year percents are the printed with-BMD quintile cells (1–2, 3–4, 5, 6–7, 8–13). Score 0 has no printed cell. Theoretical max is 15; scores ≥8 map to the 8–13 cell. Percents are not interpolated.

Formula

FRACTURE Index (with BMD) = age (<65 0, 65-69 1, 70-74 2, 75-79 3, 80-84 4, >=85 5) + total_hip_T (>= -1 0, -2 <= T < -1 2, -2.5 <= T < -2 3, T < -2.5 4) + fracture_after_50 1 + maternal_hip_fracture_after_50 1 + weight_le_125_lb 1 + current_smoker 1 + arms_to_stand 2; Black 2001; max 15; 5-year hip/vertebral/nonvertebral percents by printed quintiles 1-2, 3-4, 5, 6-7, 8-13 (score >=8 maps to 8-13); score 0 unpublished

Citation

Title: An assessment tool for predicting fracture risk in postmenopausal women
Authors: Black DM, Steinbuch M, Palermo L, et al.
Source: Osteoporos Int. 2001;12(7):519-528
DOI: 10.1007/s001980170072

Worked example

Age 60, T-score −0.5, all flags false (score 0)

Given: age=60arms_to_stand=falsebmd_t_score=-0.5current_smoker=falsefracture_after_50=falsematernal_hip_fracture_after_50=falseweight_le_125_lb=false

Age 60 is <65 → 0; T-score −0.5 is ≥ −1 → 0; five flags false → 0
Score = 0 (max 15). Black 2001 with-BMD quintile table starts at 1–2; score 0 has no printed 5-year percent.

Age 65, T-score −0.5, all flags false (quintile 1–2)

Given: age=65arms_to_stand=falsebmd_t_score=-0.5current_smoker=falsefracture_after_50=falsematernal_hip_fracture_after_50=falseweight_le_125_lb=false

Age 65 is 65–69 → 1; T-score −0.5 is ≥ −1 → 0; flags false → 0
Score = 1; printed quintile 1–2: hip 0.4%, vertebral 1.2%, nonvertebral 8.6%

Age ≥85, T-score −3.0, all flags true (maps to 8–13)

Given: age=85arms_to_stand=truebmd_t_score=-3.0current_smoker=truefracture_after_50=truematernal_hip_fracture_after_50=trueweight_le_125_lb=true

Age 85 is ≥85 → 5; T-score −3.0 is < −2.5 → 4; fracture 1 + maternal 1 + weight 1 + smoker 1 + arms 2
Score = 15 (max 15). Printed top quintile is 8–13; score ≥8 maps to that cell: hip 8.7%, vertebral 11.2%, nonvertebral 27.5%. Not a treatment order.

Also searched as

FRACTURE Index
Black FRACTURE Index
SOF fracture index
Black 2001 fracture risk
total hip T-score fracture
postmenopausal fracture index
5-year hip vertebral nonvertebral risk

Try

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

/api/calc/fracture_index?age=60&bmd_t_score=-0.5&fracture_after_50=false&maternal_hip_fracture_after_50=false&weight_le_125_lb=false&current_smoker=false&arms_to_stand=false

Full URL: https://api.magentlab.com/api/calc/fracture_index?age=60&bmd_t_score=-0.5&fracture_after_50=false&maternal_hip_fracture_after_50=false&weight_le_125_lb=false&current_smoker=false&arms_to_stand=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/fracture_index?age=60&bmd_t_score=-0.5&fracture_after_50=false&maternal_hip_fracture_after_50=false&weight_le_125_lb=false&current_smoker=false&arms_to_stand=false"

Parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (integer 18-120). Black 2001 FRACTURE Index: <65 scores 0; 65-69 scores 1; 70-74 scores 2; 75-79 scores 3; 80-84 scores 4; >=85 scores 5. Derivation was postmenopausal SOF women age 65 or older; the published instrument still lists <65 as 0.
`bmd_t_score`	number	required	Caller-assigned total-hip BMD T-score (number -5.0 to 4.0). Black 2001 with-BMD instrument: T >= -1 scores 0; -2 <= T < -1 scores 2; -2.5 <= T < -2 scores 3; T < -2.5 scores 4. magent does not DXA-scan.
`fracture_after_50`	boolean	required	Any fracture after age 50 (Black 2001). true scores 1; false scores 0. true or false. magent does not take a history.
`maternal_hip_fracture_after_50`	boolean	required	Maternal hip fracture after age 50 (Black 2001). true scores 1; false scores 0. true or false. magent does not take a history.
`weight_le_125_lb`	boolean	required	Weight 125 pounds (57 kg) or less (Black 2001). true scores 1; false scores 0. true or false. magent does not weigh the patient.
`current_smoker`	boolean	required	Current smoker (Black 2001). true scores 1; false scores 0. true or false. magent does not take a smoking history.
`arms_to_stand`	boolean	required	Usually needs arms to stand from a chair (Black 2001). true scores 2; false scores 0. true or false. magent does not examine the patient.

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/fracture_index 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": "60",
      "arms_to_stand": "false",
      "bmd_t_score": "-0.5",
      "current_smoker": "false",
      "fracture_after_50": "false",
      "maternal_hip_fracture_after_50": "false",
      "weight_le_125_lb": "false"
    },
    {
      "age": "60",
      "arms_to_stand": "false",
      "bmd_t_score": "-0.5",
      "current_smoker": "false",
      "fracture_after_50": "false",
      "maternal_hip_fracture_after_50": "false",
      "weight_le_125_lb": "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/fracture_index",
  "items": [
    {
      "components": [
        {
          "value": 60,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": -0.5,
          "factor": "bmd_t_score",
          "points": 0,
          "present": false
        },
        {
          "factor": "fracture_after_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "maternal_hip_fracture_after_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "weight_le_125_lb",
          "points": 0,
          "present": false
        },
        {
          "factor": "current_smoker",
          "points": 0,
          "present": false
        },
        {
          "factor": "arms_to_stand",
          "points": 0,
          "present": false
        }
      ],
      "age": 60,
      "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": "Black DM, Steinbuch M, Palermo L, et al.",
        "doi": "10.1007/s001980170072",
        "id": "black-2001",
        "pmid": "11527048",
        "source": "Osteoporos Int. 2001;12(7):519-528",
        "title": "An assessment tool for predicting fracture risk in postmenopausal women"
      },
      "formula": "fracture_index",
      "formula_expression": "FRACTURE Index (with BMD) = age (<65 0, 65-69 1, 70-74 2, 75-79 3, 80-84 4, >=85 5) + total_hip_T (>= -1 0, -2 <= T < -1 2, -2.5 <= T < -2 3, T < -2.5 4) + fracture_after_50 1 + maternal_hip_fracture_after_50 1 + weight_le_125_lb 1 + current_smoker 1 + arms_to_stand 2; Black 2001; max 15; 5-year hip/vertebral/nonvertebral percents by printed quintiles 1-2, 3-4, 5, 6-7, 8-13 (score >=8 maps to 8-13); score 0 unpublished",
      "max_score": 15,
      "score": 0,
      "age_score": 0,
      "arms_to_stand": false,
      "bmd_t_score": -0.5,
      "current_smoker": false,
      "fracture_after_50": false,
      "hip_risk_5y_percent": null,
      "maternal_hip_fracture_after_50": false,
      "nonvertebral_risk_5y_percent": null,
      "score_group": null,
      "t_score_points": 0,
      "vertebral_risk_5y_percent": null,
      "weight_le_125_lb": false
    },
    {
      "components": [
        {
          "value": 60,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": -0.5,
          "factor": "bmd_t_score",
          "points": 0,
          "present": false
        },
        {
          "factor": "fracture_after_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "maternal_hip_fracture_after_50",
          "points": 0,
          "present": false
        },
        {
          "factor": "weight_le_125_lb",
          "points": 0,
          "present": false
        },
        {
          "factor": "current_smoker",
          "points": 0,
          "present": false
        },
        {
          "factor": "arms_to_stand",
          "points": 0,
          "present": false
        }
      ],
      "age": 60,
      "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": "Black DM, Steinbuch M, Palermo L, et al.",
        "doi": "10.1007/s001980170072",
        "id": "black-2001",
        "pmid": "11527048",
        "source": "Osteoporos Int. 2001;12(7):519-528",
        "title": "An assessment tool for predicting fracture risk in postmenopausal women"
      },
      "formula": "fracture_index",
      "formula_expression": "FRACTURE Index (with BMD) = age (<65 0, 65-69 1, 70-74 2, 75-79 3, 80-84 4, >=85 5) + total_hip_T (>= -1 0, -2 <= T < -1 2, -2.5 <= T < -2 3, T < -2.5 4) + fracture_after_50 1 + maternal_hip_fracture_after_50 1 + weight_le_125_lb 1 + current_smoker 1 + arms_to_stand 2; Black 2001; max 15; 5-year hip/vertebral/nonvertebral percents by printed quintiles 1-2, 3-4, 5, 6-7, 8-13 (score >=8 maps to 8-13); score 0 unpublished",
      "max_score": 15,
      "score": 0,
      "age_score": 0,
      "arms_to_stand": false,
      "bmd_t_score": -0.5,
      "current_smoker": false,
      "fracture_after_50": false,
      "hip_risk_5y_percent": null,
      "maternal_hip_fracture_after_50": false,
      "nonvertebral_risk_5y_percent": null,
      "score_group": null,
      "t_score_points": 0,
      "vertebral_risk_5y_percent": null,
      "weight_le_125_lb": false
    }
  ]
}

Response

Field	Type	Description
`formula`	string	fracture_index
`formula_expression`	string	Exact Black 2001 with-BMD FRACTURE Index expression
`score`	integer	FRACTURE Index points with known BMD; published range 0-15
`max_score`	integer	15 (5 + 4 + 1 + 1 + 1 + 1 + 2)
`score_group`	string	Black 2001 with-BMD printed quintile: 1-2, 3-4, 5, 6-7, or 8-13. Score >=8 maps to 8-13. Null when score is 0 (no printed cell).
`hip_risk_5y_percent`	number	Black 2001 with-BMD 5-year hip fracture percent for that printed quintile; null when score is 0
`vertebral_risk_5y_percent`	number	Black 2001 with-BMD 5-year vertebral fracture percent for that printed quintile; null when score is 0
`nonvertebral_risk_5y_percent`	number	Black 2001 with-BMD 5-year nonvertebral fracture percent for that printed quintile; null when score is 0
`age`	integer	Caller-supplied age in years used for age points
`bmd_t_score`	number	Caller-supplied total-hip T-score used for T-score points
`fracture_after_50`	boolean	Caller-supplied fracture-after-50 flag; true scores 1
`maternal_hip_fracture_after_50`	boolean	Caller-supplied maternal hip-fracture-after-50 flag; true scores 1
`weight_le_125_lb`	boolean	Caller-supplied weight <=125 lb flag; true scores 1
`current_smoker`	boolean	Caller-supplied current-smoker flag; true scores 1
`arms_to_stand`	boolean	Caller-supplied arms-to-stand flag; true scores 2
`age_score`	integer	Age band points: 0, 1, 2, 3, 4, or 5
`t_score_points`	integer	Total-hip T-score points: 0, 2, 3, or 4
`components`	array	Per-factor points
`citation`	object	Black 2001 Osteoporos Int citation
`disclaimer`	string	Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": 60,
      "factor": "age",
      "points": 0,
      "present": false
    },
    {
      "value": -0.5,
      "factor": "bmd_t_score",
      "points": 0,
      "present": false
    },
    {
      "factor": "fracture_after_50",
      "points": 0,
      "present": false
    },
    {
      "factor": "maternal_hip_fracture_after_50",
      "points": 0,
      "present": false
    },
    {
      "factor": "weight_le_125_lb",
      "points": 0,
      "present": false
    },
    {
      "factor": "current_smoker",
      "points": 0,
      "present": false
    },
    {
      "factor": "arms_to_stand",
      "points": 0,
      "present": false
    }
  ],
  "age": 60,
  "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": "Black DM, Steinbuch M, Palermo L, et al.",
    "doi": "10.1007/s001980170072",
    "id": "black-2001",
    "pmid": "11527048",
    "source": "Osteoporos Int. 2001;12(7):519-528",
    "title": "An assessment tool for predicting fracture risk in postmenopausal women"
  },
  "formula": "fracture_index",
  "formula_expression": "FRACTURE Index (with BMD) = age (<65 0, 65-69 1, 70-74 2, 75-79 3, 80-84 4, >=85 5) + total_hip_T (>= -1 0, -2 <= T < -1 2, -2.5 <= T < -2 3, T < -2.5 4) + fracture_after_50 1 + maternal_hip_fracture_after_50 1 + weight_le_125_lb 1 + current_smoker 1 + arms_to_stand 2; Black 2001; max 15; 5-year hip/vertebral/nonvertebral percents by printed quintiles 1-2, 3-4, 5, 6-7, 8-13 (score >=8 maps to 8-13); score 0 unpublished",
  "max_score": 15,
  "score": 0,
  "age_score": 0,
  "arms_to_stand": false,
  "bmd_t_score": -0.5,
  "current_smoker": false,
  "fracture_after_50": false,
  "hip_risk_5y_percent": null,
  "maternal_hip_fracture_after_50": false,
  "nonvertebral_risk_5y_percent": null,
  "score_group": null,
  "t_score_points": 0,
  "vertebral_risk_5y_percent": null,
  "weight_le_125_lb": false
}

Client errors (HTTP 400)

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

HTTP	Code	When
400	`invalid_age`	age must be an integer from 18 to 120 Returned before settlement; you are not charged.
400	`invalid_t_score`	bmd_t_score must be a number from -5.0 to 4.0 (Black 2001 Fracture Index T-score). 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

OSTA — Compute the Koh 2001 Osteoporosis Self-Assessment Tool for Asians (OSTA) as trunc(0.2 × (weight_kg − age)) toward zero, then the published low, intermediate, or high band.
ORAI — Sum Cadarette 2000 ORAI (age, weight, and current estrogen use) and return the Table 4 point total with select_for_dxa (score ≥9) or do_not_select.
OSIRIS — Compute the Sedrine 2002 Osteoporosis Index of Risk (OSIRIS) as (-0.2 × age) + (0.2 × weight_kg) + 2 if current HRT/estrogen use + (-2) if prior low-impact fracture, rounded to 1 decimal, then the published low, intermediate, or high band.

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.