# Apfel 1999 PONV Risk Score Calculator

> Apfel 1999 PONV 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).

Calculates the simplified Apfel 1999 PONV (postoperative nausea and vomiting) risk score (0–4) from four binary predictors: female sex, history of motion sickness or PONV, nonsmoking status, and postoperative opioid use.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/apfel
- 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/apfel-1999-ponv-risk-score-calculator-f3ea4dac
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UdIIjrGu4-GmsFzEO4hAk

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 apfel-1999-ponv-risk-score-calculator-f3ea4dac
```

Example prompt: Calculate the Apfel 1999 PONV score for a female nonsmoker with a history of motion sickness who will be receiving postoperative opioids.

## When to prefer this

Use this endpoint when you need a fast, deterministic computation of the Apfel 1999 simplified four-factor PONV risk score in an automated or agentic workflow. Prefer it over manual calculation or general-purpose LLM reasoning when auditability, consistency, and structured output are required for perioperative risk documentation or decision support pipelines.

## Known failure modes

- Missing required query parameters (sex, history_motion_sickness_or_ponv, nonsmoker, postoperative_opioids) returns a validation error
- Invalid enum value for sex (anything other than 'female' or 'male') results in a schema error
- Non-boolean values for boolean fields cause a request error
- Payment not included or insufficient (x402 protocol) results in a 402 Payment Required response

## How this service works

Apfel 1999 simplified PONV risk score. Four caller-assigned predictors, 1 each, max 4: female sex, history of motion sickness or PONV, nonsmoking, postoperative opioids. Male and smokers score 0 on those items. Returns the integer score as bands 0-4. Apfel 1999 reported incidences by score; this tool returns the integer score without those percents. Not a medical device, not a prophylaxis order, not a diagnosis of PONV. Caller assigns history and opioid plan; magent does not take an anesthetic.

## Output

Returns an integer Apfel PONV risk score between 0 and 4, representing the sum of the four binary risk factors (female sex, history of motion sickness or PONV, nonsmoking, postoperative opioids). Does not return incidence percentages, prophylaxis recommendations, or a diagnosis.

## 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": [
      "sex",
      "history_motion_sickness_or_ponv",
      "nonsmoker",
      "postoperative_opioids"
     ],
     "properties": {
      "sex": {
       "enum": [
        "female",
        "male"
       ],
       "type": "string",
       "description": "female or male (Apfel 1999). Female scores 1. Male scores 0. Assigned by the caller."
      },
      "nonsmoker": {
       "type": "boolean",
       "description": "Nonsmoking status (Apfel 1999). true scores 1. Smokers (false) score 0. Assigned by the caller."
      },
      "postoperative_opioids": {
       "type": "boolean",
       "description": "Postoperative opioids planned or given (Apfel 1999). true or false as assigned by the caller. 1 point if true. magent does not take an anesthetic."
      },
      "history_motion_sickness_or_ponv": {
       "type": "boolean",
       "description": "History of motion sickness or postoperative nausea and vomiting (Apfel 1999). true or false as assigned by the caller. 1 point if true."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "path": "/api/calc/apfel",
  "count": 2,
  "items": [
   {
    "sex": "male",
    "band": "0",
    "score": 0,
    "formula": "apfel",
    "citation": {
     "id": "apfel-1999",
     "doi": "10.1097/00000542-199909000-00022",
     "pmid": "10485781",
     "title": "A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers.",
     "source": "Anesthesiology. 1999;91(3):693-700",
     "authors": "Apfel CC, Läärä E, Koivuranta M, Greim CA, Roewer N"
    },
    "max_score": 4,
    "components": [
     {
      "factor": "female",
      "points": 0,
      "present": false
     },
     {
      "factor": "history_motion_sickness_or_ponv",
      "points": 0,
      "present": false
     },
     {
      "factor": "nonsmoker",
      "points": 0,
      "present": false
     },
     {
      "factor": "postoperative_opioids",
      "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.",
    "formula_expression": "Apfel = female + history_motion_sickness_or_ponv + nonsmoker + postoperative_opioids; each 1 if true; max 4"
   },
   {
    "sex": "male",
    "band": "0",
    "score": 0,
    "formula": "apfel",
    "citation": {
     "id": "apfel-1999",
     "doi": "10.1097/00000542-199909000-00022",
     "pmid": "10485781",
     "title": "A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers.",
     "source": "Anesthesiology. 1999;91(3):693-700",
     "authors": "Apfel CC, Läärä E, Koivuranta M, Greim CA, Roewer N"
    },
    "max_score": 4,
    "components": [
     {
      "factor": "female",
      "points": 0,
      "present": false
     },
     {
      "factor": "history_motion_sickness_or_ponv",
      "points": 0,
      "present": false
     },
     {
      "factor": "nonsmoker",
      "points": 0,
      "present": false
     },
     {
      "factor": "postoperative_opioids",
      "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.",
    "formula_expression": "Apfel = female + history_motion_sickness
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apfel-1999-ponv-risk-score-calculator-f3ea4dac/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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