MAGENT

Hematology · LIVE

HIT Expert Probability (HEP) score

HEP score

Sum the Cuker 2010 HIT Expert Probability (HEP) eight clinical features with published signed integer weights and return the 2010 cutoff-2 and cutoff-5 operating points.

LIVE $0.005 USDC GET /api/calc/hep

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

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

What it computes

Sum the Cuker 2010 HIT Expert Probability (HEP) eight clinical features with published signed integer weights and return the 2010 cutoff-2 and cutoff-5 operating points.

When to use

When an agent has already applied the Cuker 2010 HEP table and needs the published signed total, not a 4Ts score, HIT antibody result, SRA, or ELISA.

When not to use

  • Not a medical device. Not a diagnosis of HIT.
  • This is the Cuker 2010 HEP score, not the 4Ts score (Lo 2006) and not a HIT antibody, SRA, or ELISA result.
  • Items are caller-assigned from the published 2010 table. magent does not grade platelet counts, day of onset, or assay SRA/ELISA.
  • Cutoff 2 (100% sensitive / 60% specific vs expert panel) and cutoff 5 (86% / 88%) are 2010 operating-characteristic points, not a HIT diagnosis.

Formula

HEP = magnitude (lt_30 -1, 30_to_50 1, gt_50 3) + timing (typical_lt_4 -2, typical_day_4 2, typical_5_10 3, typical_11_14 2, typical_gt_14 -1; rapid_lt_48h 2, rapid_gt_48h -1) + nadir (le_20 -2, gt_20 2) + thrombosis select at most one (none 0; typical_new_ge_4d 3, typical_progression 2; rapid_new 3, rapid_progression 2) + skin_necrosis 3 + systemic_reaction 2 + bleeding -1 + other causes select all (chronic_thrombocytopenia -1, new_drug_thrombocytopenia -2, severe_infection -2, overt_dic -2, intra_arterial_device -2, cpb_96h -1, no_other_cause 3 mutually exclusive with other causes); Cuker 2010; range -16 to 19; cutoff 2 was 100% sensitive / 60% specific vs expert panel; cutoff 5 was 86% sensitive / 88% specific

Citation

Title
The HIT Expert Probability (HEP) Score: a novel pre-test probability model for heparin-induced thrombocytopenia based on broad expert opinion
Authors
Cuker A, Arepally G, Crowther MA, Rice L, Datko F, Hook K, Propert KJ, Kuter DJ, Ortel TL, Konkle BA, Cines DB
Source
J Thromb Haemost. 2010;8(12):2642-2650
DOI
10.1111/j.1538-7836.2010.04059.x

Worked example

Typical-onset high features, no other cause

Given: bleeding=falsechronic_thrombocytopenia=falsecpb_96h=falseintra_arterial_device=falsemagnitude=gt_50nadir=gt_20new_drug_thrombocytopenia=falseno_other_cause=trueovert_dic=falsesevere_infection=falseskin_necrosis=falsesystemic_reaction=falsethrombosis=typical_new_ge_4dtiming=typical_5_10

  1. magnitude gt_50 +3; typical_5_10 +3; nadir gt_20 +2; typical_new_ge_4d +3
  2. skin_necrosis 0; systemic_reaction 0; bleeding 0; no_other_cause +3
  3. Score = 14 (max 19); score_ge_2 true; score_ge_5 true

Also searched as

  • HIT Expert Probability
  • HEP score
  • Cuker HEP
  • heparin-induced thrombocytopenia HEP
  • HEP pretest HIT
  • Cuker 2010 HEP
  • HIT expert score

Try

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

/api/calc/hep?magnitude=gt_50&timing=typical_5_10&nadir=gt_20&thrombosis=typical_new_ge_4d&skin_necrosis=false&systemic_reaction=false&bleeding=false&chronic_thrombocytopenia=false&new_drug_thrombocytopenia=false&severe_infection=false&overt_dic=false&intra_arterial_device=false&cpb_96h=false&no_other_cause=true

Full URL: https://api.magentlab.com/api/calc/hep?magnitude=gt_50&timing=typical_5_10&nadir=gt_20&thrombosis=typical_new_ge_4d&skin_necrosis=false&systemic_reaction=false&bleeding=false&chronic_thrombocytopenia=false&new_drug_thrombocytopenia=false&severe_infection=false&overt_dic=false&intra_arterial_device=false&cpb_96h=false&no_other_cause=true

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/hep?magnitude=gt_50&timing=typical_5_10&nadir=gt_20&thrombosis=typical_new_ge_4d&skin_necrosis=false&systemic_reaction=false&bleeding=false&chronic_thrombocytopenia=false&new_drug_thrombocytopenia=false&severe_infection=false&overt_dic=false&intra_arterial_device=false&cpb_96h=false&no_other_cause=true"

Parameters

Name Type Required Description
magnitude string required Caller-assigned Cuker 2010 magnitude of platelet fall (peak to nadir since heparin exposure). lt_30 (<30%) scores -1; 30_to_50 (30-50%) scores 1; gt_50 (>50%) scores 3. magent does not grade platelet counts.
timing string required Caller-assigned Cuker 2010 timing. Typical-onset: typical_lt_4 (fall begins <4 days) -2; typical_day_4 (day 4) 2; typical_5_10 (days 5-10) 3; typical_11_14 (days 11-14) 2; typical_gt_14 (>14 days) -1. Rapid-onset after re-exposure within 100 days: rapid_lt_48h (<48 h) 2; rapid_gt_48h (>48 h) -1. magent does not infer day of onset.
nadir string required Caller-assigned Cuker 2010 nadir platelet count. le_20 (≤20 ×10^9/L) scores -2; gt_20 (>20 ×10^9/L) scores 2. magent does not take a raw platelet count.
thrombosis string required Caller-assigned Cuker 2010 thrombosis (select at most one). none scores 0. Typical-onset: typical_new_ge_4d (new VTE or ATE ≥4 days after heparin) 3; typical_progression (progression of preexisting VTE or ATE while receiving heparin) 2. Rapid-onset: rapid_new (new VTE or ATE after heparin) 3; rapid_progression 2.
skin_necrosis boolean required Skin necrosis at subcutaneous heparin injection sites (Cuker 2010). true scores 3; false scores 0. magent does not examine the skin.
systemic_reaction boolean required Acute systemic reaction after intravenous heparin bolus (Cuker 2010). true scores 2; false scores 0.
bleeding boolean required Presence of bleeding, petechiae, or extensive bruising (Cuker 2010). true scores -1; false scores 0.
chronic_thrombocytopenia boolean required Presence of a chronic thrombocytopenic disorder (Cuker 2010 other causes; select all that apply). true scores -1. Mutually exclusive with no_other_cause true.
new_drug_thrombocytopenia boolean required Newly initiated non-heparin medication known to cause thrombocytopenia (Cuker 2010). true scores -2. Mutually exclusive with no_other_cause true.
severe_infection boolean required Severe infection as an other cause of thrombocytopenia (Cuker 2010). true scores -2. Mutually exclusive with no_other_cause true.
overt_dic boolean required Overt DIC as assigned by the caller (Cuker 2010: fibrinogen <100 mg/dL and D-dimer >5.0 μg/mL). true scores -2. magent does not assay fibrinogen or D-dimer. Mutually exclusive with no_other_cause true.
intra_arterial_device boolean required Indwelling intra-arterial device (Cuker 2010 examples: IABP, VAD, ECMO). true scores -2. Mutually exclusive with no_other_cause true.
cpb_96h boolean required Cardiopulmonary bypass within the previous 96 hours (Cuker 2010). true scores -1. Mutually exclusive with no_other_cause true.
no_other_cause boolean required No other apparent cause of thrombocytopenia (Cuker 2010). true scores 3. Must be false if any other-cause flag is true.

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/hep 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": [
    {
      "bleeding": "false",
      "chronic_thrombocytopenia": "false",
      "cpb_96h": "false",
      "intra_arterial_device": "false",
      "magnitude": "gt_50",
      "nadir": "gt_20",
      "new_drug_thrombocytopenia": "false",
      "no_other_cause": "true",
      "overt_dic": "false",
      "severe_infection": "false",
      "skin_necrosis": "false",
      "systemic_reaction": "false",
      "thrombosis": "typical_new_ge_4d",
      "timing": "typical_5_10"
    },
    {
      "bleeding": "false",
      "chronic_thrombocytopenia": "false",
      "cpb_96h": "false",
      "intra_arterial_device": "false",
      "magnitude": "gt_50",
      "nadir": "gt_20",
      "new_drug_thrombocytopenia": "false",
      "no_other_cause": "true",
      "overt_dic": "false",
      "severe_infection": "false",
      "skin_necrosis": "false",
      "systemic_reaction": "false",
      "thrombosis": "typical_new_ge_4d",
      "timing": "typical_5_10"
    }
  ]
}

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/hep",
  "items": [
    {
      "components": [
        {
          "value": "gt_50",
          "factor": "magnitude",
          "points": 3,
          "present": true
        },
        {
          "value": "typical_5_10",
          "factor": "timing",
          "points": 3,
          "present": true
        },
        {
          "value": "gt_20",
          "factor": "nadir",
          "points": 2,
          "present": true
        },
        {
          "value": "typical_new_ge_4d",
          "factor": "thrombosis",
          "points": 3,
          "present": true
        },
        {
          "factor": "skin_necrosis",
          "points": 0,
          "present": false
        },
        {
          "factor": "systemic_reaction",
          "points": 0,
          "present": false
        },
        {
          "factor": "bleeding",
          "points": 0,
          "present": false
        },
        {
          "factor": "chronic_thrombocytopenia",
          "points": 0,
          "present": false
        },
        {
          "factor": "new_drug_thrombocytopenia",
          "points": 0,
          "present": false
        },
        {
          "factor": "severe_infection",
          "points": 0,
          "present": false
        },
        {
          "factor": "overt_dic",
          "points": 0,
          "present": false
        },
        {
          "factor": "intra_arterial_device",
          "points": 0,
          "present": false
        },
        {
          "factor": "cpb_96h",
          "points": 0,
          "present": false
        },
        {
          "factor": "no_other_cause",
          "points": 3,
          "present": true
        }
      ],
      "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": "Cuker A, Arepally G, Crowther MA, Rice L, Datko F, Hook K, Propert KJ, Kuter DJ, Ortel TL, Konkle BA, Cines DB",
        "doi": "10.1111/j.1538-7836.2010.04059.x",
        "id": "cuker-2010",
        "pmid": "20854372",
        "source": "J Thromb Haemost. 2010;8(12):2642-2650",
        "title": "The HIT Expert Probability (HEP) Score: a novel pre-test probability model for heparin-induced thrombocytopenia based on broad expert opinion"
      },
      "formula": "hep",
      "formula_expression": "HEP = magnitude (lt_30 -1, 30_to_50 1, gt_50 3) + timing (typical_lt_4 -2, typical_day_4 2, typical_5_10 3, typical_11_14 2, typical_gt_14 -1; rapid_lt_48h 2, rapid_gt_48h -1) + nadir (le_20 -2, gt_20 2) + thrombosis select at most one (none 0; typical_new_ge_4d 3, typical_progression 2; rapid_new 3, rapid_progression 2) + skin_necrosis 3 + systemic_reaction 2 + bleeding -1 + other causes select all (chronic_thrombocytopenia -1, new_drug_thrombocytopenia -2, severe_infection -2, overt_dic -2, intra_arterial_device -2, cpb_96h -1, no_other_cause 3 mutually exclusive with other causes); Cuker 2010; range -16 to 19; cutoff 2 was 100% sensitive / 60% specific vs expert panel; cutoff 5 was 86% sensitive / 88% specific",
      "max_score": 19,
      "score": 14,
      "score_ge_2": true,
      "score_ge_5": true
    },
    {
      "components": [
        {
          "value": "gt_50",
          "factor": "magnitude",
          "points": 3,
          "present": true
        },
        {
          "value": "typical_5_10",
          "factor": "timing",
          "points": 3,
          "present": true
        },
        {
          "value": "gt_20",
          "factor": "nadir",
          "points": 2,
          "present": true
        },
        {
          "value": "typical_new_ge_4d",
          "factor": "thrombosis",
          "points": 3,
          "present": true
        },
        {
          "factor": "skin_necrosis",
          "points": 0,
          "present": false
        },
        {
          "factor": "systemic_reaction",
          "points": 0,
          "present": false
        },
        {
          "factor": "bleeding",
          "points": 0,
          "present": false
        },
        {
          "factor": "chronic_thrombocytopenia",
          "points": 0,
          "present": false
        },
        {
          "factor": "new_drug_thrombocytopenia",
          "points": 0,
          "present": false
        },
        {
          "factor": "severe_infection",
          "points": 0,
          "present": false
        },
        {
          "factor": "overt_dic",
          "points": 0,
          "present": false
        },
        {
          "factor": "intra_arterial_device",
          "points": 0,
          "present": false
        },
        {
          "factor": "cpb_96h",
          "points": 0,
          "present": false
        },
        {
          "factor": "no_other_cause",
          "points": 3,
          "present": true
        }
      ],
      "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": "Cuker A, Arepally G, Crowther MA, Rice L, Datko F, Hook K, Propert KJ, Kuter DJ, Ortel TL, Konkle BA, Cines DB",
        "doi": "10.1111/j.1538-7836.2010.04059.x",
        "id": "cuker-2010",
        "pmid": "20854372",
        "source": "J Thromb Haemost. 2010;8(12):2642-2650",
        "title": "The HIT Expert Probability (HEP) Score: a novel pre-test probability model for heparin-induced thrombocytopenia based on broad expert opinion"
      },
      "formula": "hep",
      "formula_expression": "HEP = magnitude (lt_30 -1, 30_to_50 1, gt_50 3) + timing (typical_lt_4 -2, typical_day_4 2, typical_5_10 3, typical_11_14 2, typical_gt_14 -1; rapid_lt_48h 2, rapid_gt_48h -1) + nadir (le_20 -2, gt_20 2) + thrombosis select at most one (none 0; typical_new_ge_4d 3, typical_progression 2; rapid_new 3, rapid_progression 2) + skin_necrosis 3 + systemic_reaction 2 + bleeding -1 + other causes select all (chronic_thrombocytopenia -1, new_drug_thrombocytopenia -2, severe_infection -2, overt_dic -2, intra_arterial_device -2, cpb_96h -1, no_other_cause 3 mutually exclusive with other causes); Cuker 2010; range -16 to 19; cutoff 2 was 100% sensitive / 60% specific vs expert panel; cutoff 5 was 86% sensitive / 88% specific",
      "max_score": 19,
      "score": 14,
      "score_ge_2": true,
      "score_ge_5": true
    }
  ]
}

Response

Field Type Description
formula string hep
formula_expression string Exact expression used
score integer HEP points (signed; published range -16 to 19)
max_score integer 19
score_ge_2 boolean true iff score ≥ 2 (Cuker 2010 cutoff 2: 100% sensitive / 60% specific vs expert panel). Not a HIT diagnosis.
score_ge_5 boolean true iff score ≥ 5 (Cuker 2010 cutoff 5: 86% sensitive / 88% specific). Not a HIT diagnosis.
components array Per-feature signed points
citation object Cuker 2010 citation
disclaimer string Not-a-device notice

Example JSON

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

{
  "components": [
    {
      "value": "gt_50",
      "factor": "magnitude",
      "points": 3,
      "present": true
    },
    {
      "value": "typical_5_10",
      "factor": "timing",
      "points": 3,
      "present": true
    },
    {
      "value": "gt_20",
      "factor": "nadir",
      "points": 2,
      "present": true
    },
    {
      "value": "typical_new_ge_4d",
      "factor": "thrombosis",
      "points": 3,
      "present": true
    },
    {
      "factor": "skin_necrosis",
      "points": 0,
      "present": false
    },
    {
      "factor": "systemic_reaction",
      "points": 0,
      "present": false
    },
    {
      "factor": "bleeding",
      "points": 0,
      "present": false
    },
    {
      "factor": "chronic_thrombocytopenia",
      "points": 0,
      "present": false
    },
    {
      "factor": "new_drug_thrombocytopenia",
      "points": 0,
      "present": false
    },
    {
      "factor": "severe_infection",
      "points": 0,
      "present": false
    },
    {
      "factor": "overt_dic",
      "points": 0,
      "present": false
    },
    {
      "factor": "intra_arterial_device",
      "points": 0,
      "present": false
    },
    {
      "factor": "cpb_96h",
      "points": 0,
      "present": false
    },
    {
      "factor": "no_other_cause",
      "points": 3,
      "present": true
    }
  ],
  "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": "Cuker A, Arepally G, Crowther MA, Rice L, Datko F, Hook K, Propert KJ, Kuter DJ, Ortel TL, Konkle BA, Cines DB",
    "doi": "10.1111/j.1538-7836.2010.04059.x",
    "id": "cuker-2010",
    "pmid": "20854372",
    "source": "J Thromb Haemost. 2010;8(12):2642-2650",
    "title": "The HIT Expert Probability (HEP) Score: a novel pre-test probability model for heparin-induced thrombocytopenia based on broad expert opinion"
  },
  "formula": "hep",
  "formula_expression": "HEP = magnitude (lt_30 -1, 30_to_50 1, gt_50 3) + timing (typical_lt_4 -2, typical_day_4 2, typical_5_10 3, typical_11_14 2, typical_gt_14 -1; rapid_lt_48h 2, rapid_gt_48h -1) + nadir (le_20 -2, gt_20 2) + thrombosis select at most one (none 0; typical_new_ge_4d 3, typical_progression 2; rapid_new 3, rapid_progression 2) + skin_necrosis 3 + systemic_reaction 2 + bleeding -1 + other causes select all (chronic_thrombocytopenia -1, new_drug_thrombocytopenia -2, severe_infection -2, overt_dic -2, intra_arterial_device -2, cpb_96h -1, no_other_cause 3 mutually exclusive with other causes); Cuker 2010; range -16 to 19; cutoff 2 was 100% sensitive / 60% specific vs expert panel; cutoff 5 was 86% sensitive / 88% specific",
  "max_score": 19,
  "score": 14,
  "score_ge_2": true,
  "score_ge_5": true
}

Client errors (HTTP 400)

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

HTTP Code When
400 invalid_hep HEP items must use Cuker 2010 Table point values (signed integers as published; not the 4Ts score). 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

  • 4Ts score — Compute the Lo 2006 4Ts score as the sum of four caller-assigned integers 0-2 (thrombocytopenia, timing, thrombosis, other causes).
  • PLASMIC score — Sum the seven Bendapudi 2017 PLASMIC items and return the published 0-4 / 5 / 6-7 pretest band for severe ADAMTS13 deficiency.
  • ISTH overt DIC — Sum the four Taylor 2001 ISTH SSC overt DIC laboratory items (platelets, fibrin-related marker, PT prolongation, fibrinogen) and return the published <5 / >=5 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.