Ottawa Heart Failure Risk Scale (OHFRS; Stiell 2013 derivation)
Ottawa Heart Failure Risk Scale (OHFRS; Stiell 2013 derivation). Ten caller-assigned flags (stroke/TIA 1, intubation 2, arrival HR >=110 2, arrival SaO2 <90% 1, walk-test HR >=110 or unable 1, new ischemic ECG 2, urea >=12 mmol/L 1, CO2 >=35 mmol/L 2, troponin at MI level 2, NT-proBNP >=5000 ng/L 1); integer points, max 15. Derivation SAE risk 2.8% to 89.0%. Not a medical device, not a disposition or discharge order, not EHMRG. magent does not walk the patient or read the ECG.
Asked 1.4x its listed price for its own exampleour last check, 2026-09-28
1 of 1checks answered this week
467 msmedian answer time
$0.005listed price per call
$0.007price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.magentlab.com/api/calc/ohfrs
| Category | Everything else |
|---|---|
| Provider host | api.magentlab.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.007 | 467 ms |
Example input (from the provider)
{
"body": {
"items": [
{
"co2_ge_35_mmol_l": false,
"history_stroke_or_tia": false,
"hr_arrival_ge_110": false,
"intubation_respiratory_distress": false,
"new_ischemic_ecg": false,
"ntprobnp_ge_5000": false,
"sao2_lt_90_arrival": false,
"troponin_mi_level": false,
"urea_ge_12_mmol_l": false,
"walk_test_hr_ge_110_or_unable": false
},
{
"co2_ge_35_mmol_l": false,
"history_stroke_or_tia": false,
"hr_arrival_ge_110": false,
"intubation_respiratory_distress": false,
"new_ischemic_ecg": false,
"ntprobnp_ge_5000": false,
"sao2_lt_90_arrival": false,
"troponin_mi_level": false,
"urea_ge_12_mmol_l": false,
"walk_test_hr_ge_110_or_unable": false
}
]
},
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"items": {
"items": {
"properties": {
"co2_ge_35_mmol_l": {
"description": "Serum CO2 >=35 mmol/L as assigned by the caller after applying the Stiell 2013 cutoff (2 points if true). true or false. magent does not assay CO2.",
"type": "boolean"
},
"history_stroke_or_tia": {
"description": "History of stroke or TIA as assigned by the caller (Stiell 2013; 1 point if true). true or false. magent does not take the history.",
"type": "boolean"
},
"hr_arrival_ge_110": {
"description": "Heart rate on ED arrival >=110 as assigned by the caller after applying the Stiell 2013 cutoff (2 points if true). true or false. magent does not measure heart rate.",
"type": "boolean"
},
"intubation_respiratory_distress": {
"description": "Intubation for respiratory distress as assigned by the caller (Stiell 2013; 2 points if true). true or false.",
"type": "boolean"
},
"new_ischemic_ecg": {
"description": "New ischemic ECG changes as assigned by the caller (Stiell 2013 derivation; 2 points if true). true or false. magent does not interpret the ECG.",
"type": "boolean"
},
"ntprobnp_ge_5000": {
"description": "NT-proBNP >=5000 ng/L as assigned by the caller after applying the Stiell 2013 cutoff (1 point if true). true or false. magent does not assay NT-proBNP.",
"type": "boolean"
},
"sao2_lt_90_arrival": {
"description": "Oxygen saturation <90% on ED arrival as assigned by the caller after applying the Stiell 2013 cutoff (1 point if true). true or false. magent does not measure saturation.",
"type": "boolean"
},
"troponin_mi_level": {
"description": "Troponin I or T elevated to MI level as assigned by the caller (Stiell 2013; 2 points if true). true or false. magent does not assay troponin.",
"type": "boolean"
},
"urea_ge_12_mmol_l": {
"description": "Urea >=12 mmol/L as assigned by the caller after applying the Stiell 2013 cutoff (1 point if true). true or false. magent does not assay urea.",
"type": "boolean"
},
"walk_test_hr_ge_110_or_unable": {
"description": "Heart rate >=110 during the 3-minute walk test, or unable to perform the walk test, as assigned by the caller after ED intervention (Stiell 2013; 1 point if true). true or false. magent does not walk the patient.",
"type": "boolean"
}
},
"required": [
"history_stroke_or_tia",
"intubation_respiratory_distress",
"hr_arrival_ge_110",
"sao2_lt_90_arrival",
"walk_test_hr_ge_110_or_unable",
"new_ischemic_ecg",
"urea_ge_12_mmol_l",
"co2_ge_35_mmol_l",
"troponin_mi_level",
"ntprobnp_ge_5000"
],
"type": "object"
},
"maxItems": 25,
"minItems": 1,
"type": "array"
}
},
"required": [
"items"
],
"type": "object"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"const": "POST",
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}