MAGENT

Hemodynamics · LIVE

Duke Activity Status Index

DASI

Sum the Hlatky 1989 Duke Activity Status Index Table I weights for 12 yes/no activities and return DASI and estimated peak VO2.

LIVE $0.005 USDC GET /api/calc/dasi

Markdown: /docs/dasi.md · Canonical: https://magentlab.com/docs/dasi

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

What it computes

Sum the Hlatky 1989 Duke Activity Status Index Table I weights for 12 yes/no activities and return DASI and estimated peak VO2.

When to use

When an agent has caller-assigned yes/no replies to the twelve Hlatky 1989 DASI activities and needs the published weighted sum and VO2peak regression, not an exercise test or a functional-capacity assignment.

When not to use

  • Not a medical device. magent does not observe the patient.
  • Not a functional-capacity assignment, exercise-test replacement, or cardiopulmonary exercise prescription.
  • Yes/no replies are caller-assigned from the Hlatky 1989 Table I questionnaire. magent does not interview the patient or measure oxygen uptake.
  • This is the Hlatky 1989 questionnaire sum and VO2peak = 0.43 x DASI + 9.6 regression only. It does not convert VO2peak to METs and does not apply a later perioperative functional-capacity cutoff.

Formula

DASI = 2.75*self_care + 1.75*walk_indoors + 2.75*walk_blocks + 5.50*climb_stairs + 8.00*run_short + 2.70*light_housework + 3.50*moderate_housework + 8.00*heavy_housework + 4.50*yardwork + 5.25*sexual_relations + 6.00*moderate_recreation + 7.50*strenuous_sports (Yes = weight, No = 0); VO2peak_mL/kg/min = 0.43*DASI + 9.6 (Hlatky 1989 Table I)

Citation

Title
A brief self-administered questionnaire to determine functional capacity (The Duke Activity Status Index)
Authors
Hlatky MA, Boineau RE, Higginbotham MB, Lee KL, Mark DB, Califf RM, Cobb FR, Pryor DB
Source
Am J Cardiol. 1989;64(10):651-654
DOI
10.1016/0002-9149(89)90496-7

Worked example

All 12 activities false

Given: climb_stairs=falseheavy_housework=falselight_housework=falsemoderate_housework=falsemoderate_recreation=falserun_short=falseself_care=falsesexual_relations=falsestrenuous_sports=falsewalk_blocks=falsewalk_indoors=falseyardwork=false

  1. Each No adds 0
  2. DASI = 0.0 (max 58.2)
  3. VO2peak = 0.43 * 0.0 + 9.6 = 9.6 mL/kg/min

All 12 activities true

Given: climb_stairs=trueheavy_housework=truelight_housework=truemoderate_housework=truemoderate_recreation=truerun_short=trueself_care=truesexual_relations=truestrenuous_sports=truewalk_blocks=truewalk_indoors=trueyardwork=true

  1. Sum of Table I weights = 58.2 (light housework is 2.70)
  2. DASI = 58.2 (max 58.2)
  3. VO2peak = 0.43 * 58.2 + 9.6 = 34.6 mL/kg/min

Also searched as

  • Duke Activity Status Index
  • DASI
  • Duke Activity Status
  • Hlatky DASI
  • DASI questionnaire
  • DASI VO2peak
  • functional capacity index
  • Duke activity questionnaire

Try

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

/api/calc/dasi?self_care=false&walk_indoors=false&walk_blocks=false&climb_stairs=false&run_short=false&light_housework=false&moderate_housework=false&heavy_housework=false&yardwork=false&sexual_relations=false&moderate_recreation=false&strenuous_sports=false

Full URL: https://api.magentlab.com/api/calc/dasi?self_care=false&walk_indoors=false&walk_blocks=false&climb_stairs=false&run_short=false&light_housework=false&moderate_housework=false&heavy_housework=false&yardwork=false&sexual_relations=false&moderate_recreation=false&strenuous_sports=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/dasi?self_care=false&walk_indoors=false&walk_blocks=false&climb_stairs=false&run_short=false&light_housework=false&moderate_housework=false&heavy_housework=false&yardwork=false&sexual_relations=false&moderate_recreation=false&strenuous_sports=false"

Parameters

Name Type Required Description
self_care boolean required Can take care of self: eating, dressing, bathing, or using the toilet (Hlatky 1989 Table I). true or false. Yes adds 2.75.
walk_indoors boolean required Can walk indoors, such as around the house (Hlatky 1989 Table I). true or false. Yes adds 1.75.
walk_blocks boolean required Can walk a block or two on level ground (Hlatky 1989 Table I). true or false. Yes adds 2.75.
climb_stairs boolean required Can climb a flight of stairs or walk up a hill (Hlatky 1989 Table I). true or false. Yes adds 5.50.
run_short boolean required Can run a short distance (Hlatky 1989 Table I). true or false. Yes adds 8.00.
light_housework boolean required Can do light work around the house like dusting or washing dishes (Hlatky 1989 Table I). true or false. Yes adds 2.70.
moderate_housework boolean required Can do moderate work around the house like vacuuming, sweeping floors, or carrying in groceries (Hlatky 1989 Table I). true or false. Yes adds 3.50.
heavy_housework boolean required Can do heavy work around the house like scrubbing floors, or lifting or moving heavy furniture (Hlatky 1989 Table I). true or false. Yes adds 8.00.
yardwork boolean required Can do yardwork like raking leaves, weeding, or pushing a power mower (Hlatky 1989 Table I). true or false. Yes adds 4.50.
sexual_relations boolean required Can have sexual relations (Hlatky 1989 Table I). true or false. Yes adds 5.25.
moderate_recreation boolean required Can participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football (Hlatky 1989 Table I). true or false. Yes adds 6.00.
strenuous_sports boolean required Can participate in strenuous sports like swimming, singles tennis, football, basketball, or skiing (Hlatky 1989 Table I). true or false. Yes adds 7.50.

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/dasi 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": [
    {
      "climb_stairs": "false",
      "heavy_housework": "false",
      "light_housework": "false",
      "moderate_housework": "false",
      "moderate_recreation": "false",
      "run_short": "false",
      "self_care": "false",
      "sexual_relations": "false",
      "strenuous_sports": "false",
      "walk_blocks": "false",
      "walk_indoors": "false",
      "yardwork": "false"
    },
    {
      "climb_stairs": "false",
      "heavy_housework": "false",
      "light_housework": "false",
      "moderate_housework": "false",
      "moderate_recreation": "false",
      "run_short": "false",
      "self_care": "false",
      "sexual_relations": "false",
      "strenuous_sports": "false",
      "walk_blocks": "false",
      "walk_indoors": "false",
      "yardwork": "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/dasi",
  "items": [
    {
      "components": [
        {
          "factor": "self_care",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "walk_indoors",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "walk_blocks",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "climb_stairs",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "run_short",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "light_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "moderate_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "heavy_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "yardwork",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "sexual_relations",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "moderate_recreation",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "strenuous_sports",
          "points": 0.0,
          "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": "Hlatky MA, Boineau RE, Higginbotham MB, Lee KL, Mark DB, Califf RM, Cobb FR, Pryor DB",
        "doi": "10.1016/0002-9149(89)90496-7",
        "id": "hlatky-1989",
        "pmid": "2782256",
        "source": "Am J Cardiol. 1989;64(10):651-654",
        "title": "A brief self-administered questionnaire to determine functional capacity (The Duke Activity Status Index)"
      },
      "formula": "dasi",
      "formula_expression": "DASI = 2.75*self_care + 1.75*walk_indoors + 2.75*walk_blocks + 5.50*climb_stairs + 8.00*run_short + 2.70*light_housework + 3.50*moderate_housework + 8.00*heavy_housework + 4.50*yardwork + 5.25*sexual_relations + 6.00*moderate_recreation + 7.50*strenuous_sports (Yes = weight, No = 0); VO2peak_mL/kg/min = 0.43*DASI + 9.6 (Hlatky 1989 Table I)",
      "max_score": 58.2,
      "score": 0.0,
      "dasi": 0.0,
      "vo2peak_ml_kg_min": 9.6
    },
    {
      "components": [
        {
          "factor": "self_care",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "walk_indoors",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "walk_blocks",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "climb_stairs",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "run_short",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "light_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "moderate_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "heavy_housework",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "yardwork",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "sexual_relations",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "moderate_recreation",
          "points": 0.0,
          "present": false
        },
        {
          "factor": "strenuous_sports",
          "points": 0.0,
          "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": "Hlatky MA, Boineau RE, Higginbotham MB, Lee KL, Mark DB, Califf RM, Cobb FR, Pryor DB",
        "doi": "10.1016/0002-9149(89)90496-7",
        "id": "hlatky-1989",
        "pmid": "2782256",
        "source": "Am J Cardiol. 1989;64(10):651-654",
        "title": "A brief self-administered questionnaire to determine functional capacity (The Duke Activity Status Index)"
      },
      "formula": "dasi",
      "formula_expression": "DASI = 2.75*self_care + 1.75*walk_indoors + 2.75*walk_blocks + 5.50*climb_stairs + 8.00*run_short + 2.70*light_housework + 3.50*moderate_housework + 8.00*heavy_housework + 4.50*yardwork + 5.25*sexual_relations + 6.00*moderate_recreation + 7.50*strenuous_sports (Yes = weight, No = 0); VO2peak_mL/kg/min = 0.43*DASI + 9.6 (Hlatky 1989 Table I)",
      "max_score": 58.2,
      "score": 0.0,
      "dasi": 0.0,
      "vo2peak_ml_kg_min": 9.6
    }
  ]
}

Response

Field Type Description
formula string dasi
formula_expression string Exact expression used
score number DASI (same as dasi); 0-58.2
max_score number 58.2
dasi number Hlatky 1989 Table I weighted sum (0-58.2)
vo2peak_ml_kg_min number Estimated peak VO2 in mL/kg/min = 0.43 * DASI + 9.6
components array Per-activity Table I weights
citation object Hlatky et al. Am J Cardiol 1989 citation
disclaimer string Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "factor": "self_care",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "walk_indoors",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "walk_blocks",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "climb_stairs",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "run_short",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "light_housework",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "moderate_housework",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "heavy_housework",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "yardwork",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "sexual_relations",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "moderate_recreation",
      "points": 0.0,
      "present": false
    },
    {
      "factor": "strenuous_sports",
      "points": 0.0,
      "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": "Hlatky MA, Boineau RE, Higginbotham MB, Lee KL, Mark DB, Califf RM, Cobb FR, Pryor DB",
    "doi": "10.1016/0002-9149(89)90496-7",
    "id": "hlatky-1989",
    "pmid": "2782256",
    "source": "Am J Cardiol. 1989;64(10):651-654",
    "title": "A brief self-administered questionnaire to determine functional capacity (The Duke Activity Status Index)"
  },
  "formula": "dasi",
  "formula_expression": "DASI = 2.75*self_care + 1.75*walk_indoors + 2.75*walk_blocks + 5.50*climb_stairs + 8.00*run_short + 2.70*light_housework + 3.50*moderate_housework + 8.00*heavy_housework + 4.50*yardwork + 5.25*sexual_relations + 6.00*moderate_recreation + 7.50*strenuous_sports (Yes = weight, No = 0); VO2peak_mL/kg/min = 0.43*DASI + 9.6 (Hlatky 1989 Table I)",
  "max_score": 58.2,
  "score": 0.0,
  "dasi": 0.0,
  "vo2peak_ml_kg_min": 9.6
}

Client errors (HTTP 400)

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

HTTP Code When
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

  • H2FPEF — Sum the Reddy 2018 H2FPEF points score (six components, max 9) and return score and max_score only.

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.