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LACE Readmission Risk Score Calculator
x402
LACE Readmission Risk Score Calculator 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 LACE index (0-19) for 30-day hospital readmission risk from length of stay, acute admission status, Charlson comorbidity index, and ED visit count.
Price / call$0.005
Success—
StatusUnknown
How this service works
LACE (van Walraven 2010 CMAJ Table 3) from length of stay in days (<1 0; 1 1; 2 2; 3 3; 4-6 4; 7-13 5; >=14 7), acute (emergent) admission (true 3), caller-supplied Charlson comorbidity index (0-3 identity; >=4 5), and ED visits in the previous 6 months (0-3 identity; >=4 4). Score 0-19 only; no unpublished high-risk class. Not a discharge order. magent does not compute Charlson.
Output
Returns a LACE composite score from 0 to 19, calculated by summing mapped point values for length of stay (L), acute admission status (A), caller-supplied Charlson comorbidity index (C), and ED visits in the prior 6 months (E), per van Walraven 2010 CMAJ Table 3. The endpoint does not classify risk tiers or issue clinical recommendations.
Example use cases
Discharge planning risk flag
“I need to know the LACE readmission risk score for a patient who had a 3-day stay, came in through the ER (acute admission), has a Charlson score of 4, and visited the ED twice in the past 6 months — can you compute that before we finalize discharge?”
Quality metrics reporting pipeline
“As part of our monthly readmission audit, compute the LACE index for a patient with a 14-day inpatient stay, non-acute admission, Charlson comorbidity index of 1, and zero ED visits in the prior 6 months.”
High-risk patient triage screening
“Flag whether this patient is high-risk for readmission using the LACE score — they were in the hospital for 8 days, admitted emergently, have a Charlson index of 5, and came to the ED 4 times in the last 6 months.”
Technical details
Endpoint
GEThttps://api.magentlab.com/api/calc/laceWhen to prefer
Use this endpoint when you need a fast, standards-compliant LACE index calculation and already have the Charlson comorbidity index computed externally. Prefer it over general-purpose calculators when you need strict adherence to van Walraven 2010 Table 3 mapping bins (e.g., LOS ≥14 maps to 7, not linear interpolation). Not appropriate for computing Charlson itself — use a separate Charlson calculator first. Suitable for integration into EHR discharge workflows, population health dashboards, and readmission quality reporting pipelines.
Side effects
- Missing required query parameters (length_of_stay_days, acute_admission, charlson, ed_visits_6mo) returns an error
- Non-integer values for integer fields cause validation failure
- charlson or ed_visits_6mo values below 0 or outside expected range may be rejected
- Payment not provided via x402 protocol results in 402 Payment Required
- Server-side errors return 5xx responses
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"path": "/api/calc/lace",
"count": 2,
"items": [
{
"score": 1,
"formula": "lace",
"charlson": 0,
"citation": {
"id": "van-walraven-2010",
"doi": "10.1503/cmaj.091117",
"pmid": "20194559",
"title": "Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community",
"source": "CMAJ. 2010;182(6):551-557",
"authors": "van Walraven C, Dhalla IA, Bell C, Etchells E, Stiell IG, Zarnke K, Austin PC, Forster AJ"
},
"max_score": 19,
"components": [
{
"value": 1,
"factor": "length_of_stay",
"points": 1,
"present": true
},
{
"factor": "acute_admission",
"points": 0,
"present": false
},
{
"value": 0,
"factor": "charlson",
"points": 0,
"present": false
},
{
"value": 0,
"factor": "ed_visits_6mo",
"points": 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.",
"ed_visits_6mo": 0,
"acute_admission": false,
"formula_expression": "LACE = los_points + acute_admission_points + charlson_points + ed_visits_points; van Walraven 2010 Table 3; LOS <1 0, 1 1, 2 2, 3 3, 4-6 4, 7-13 5, >=14 7; acute true 3; Charlson 0-3 identity, >=4 5; ED 0-3 identity, >=4 4; max 19",
"length_of_stay_days": 1
},
{
"score": 1,
"formula": "lace",
"charlson": 0,
"citation": {
"id": "van-walraven-2010",
"doi": "10.1503/cmaj.091117",
"pmid": "20194559",
"title": "Derivation and validation of an index to predict early death or unplanned readmission after discharge from hospital to the community",
"source": "CMAJ. 2010;182(6):551-557",
"authors": "van Walraven C, Dhalla IA, Bell C, Etchells E, Stiell IG, Zarnke K, Austin PC, Forster AJ"
},
"max_score": 19,
"components": [
{
"value": 1,
"factor": "length_of_stay",
"points": 1,
"present": true
},
{
"factor": "acute_admission",
"points": 0,
"present": false
},
{
"value": 0,
"factor": "charlson",
"points": 0,
"present": false
},
{
"value": 0,
"factor": "ed_visits_6mo",
"points": 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.",
"ed_visits_6mo": 0,
"acute_admission": false,
"formula_expression": "LACE = los_points + acute_admission_points + charlson_points + ed_visits_points; van Walraven 2010 Table 3; LOS <1 0, 1 1, 2 2, 3 3, 4-6 4, 7-13 5, >=14 7; acute true 3; Charlson 0-3 identity, >=4 5; ED 0-3 identity, >=4 4; max 19",
"length_of_stay_days": 1
}
]
}
}Tags
x402
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