# FRACTURE Index Calculator (Black 2001)

> FRACTURE Index Calculator (Black 2001) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Computes the Black 2001 FRACTURE Index score and 5-year hip/vertebral/nonvertebral fracture risk percentages from age, total-hip BMD T-score, and five clinical risk factors.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/fracture_index
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fracture-index-calculator-black-2001-90b828d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xPVDkAfN8Fe4hCa6PUvS7

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability fracture-index-calculator-black-2001-90b828d0
```

Example prompt: Using the Black 2001 FRACTURE Index, calculate the 5-year hip, vertebral, and nonvertebral fracture risk for a 72-year-old postmenopausal woman with a total-hip T-score of -2.3, a prior fracture after age 50, no maternal hip fracture, weighs over 125 lb, is a current smoker, and does not need her arms to stand.

## When to prefer this

Use this endpoint when you need the validated Black 2001 FRACTURE Index score and 5-year fracture risk estimates and already have the patient's total-hip BMD T-score from a prior DXA report. Prefer it over FRAX when the clinical workflow specifically calls for the FRACTURE Index (e.g., SOF-derived cohort benchmarking or published guideline references to Black 2001). Do not use this endpoint to order a DXA scan, collect patient history interactively, or compute FRAX-based risk.

## Known failure modes

- Age outside 18–120 range returns a validation error
- T-score outside -5.0 to 4.0 range returns a validation error
- Missing required boolean risk-factor fields returns a 400 error
- Ambiguous or non-integer age value causes a schema error
- Payment failure (x402) if USDC balance is insufficient

## How this service works

Black 2001 FRACTURE Index with known total-hip T-score. Age <65 0 through >=85 5. T >= -1 0; -2 <= T < -1 2; -2.5 <= T < -2 3; T < -2.5 4. Fracture after 50, maternal hip after 50, weight <=125 lb, smoker +1 each; arms to stand +2. Max 15. 5-year hip/vertebral/nonvertebral percents from printed quintiles 1-2, 3-4, 5, 6-7, 8-13. Age 18-120; T -5.0 to 4.0. Not a device, not FRAX, not a DXA order. Postmenopausal derivation; magent does not DXA-scan or take a history.

## Output

Returns the integer FRACTURE Index score (0–15), the risk quintile band, and estimated 5-year percentage risks for hip, vertebral, and nonvertebral fractures derived from the published Black 2001 quintile lookup table.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "age",
      "bmd_t_score",
      "fracture_after_50",
      "maternal_hip_fracture_after_50",
      "weight_le_125_lb",
      "current_smoker",
      "arms_to_stand"
     ],
     "properties": {
      "age": {
       "type": "integer",
       "description": "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": {
       "type": "number",
       "description": "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."
      },
      "arms_to_stand": {
       "type": "boolean",
       "description": "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."
      },
      "current_smoker": {
       "type": "boolean",
       "description": "Current smoker (Black 2001). true scores 1; false scores 0. true or false. magent does not take a smoking history."
      },
      "weight_le_125_lb": {
       "type": "boolean",
       "description": "Weight 125 pounds (57 kg) or less (Black 2001). true scores 1; false scores 0. true or false. magent does not weigh the patient."
      },
      "fracture_after_50": {
       "type": "boolean",
       "description": "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": {
       "type": "boolean",
       "description": "Maternal hip fracture after age 50 (Black 2001). true scores 1; false scores 0. true or false. magent does not take a history."
      }
     }
    }
   },
   "additionalPropert
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fracture-index-calculator-black-2001-90b828d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)