# Ho 2004 IV-Steroid Day-3 Score for Severe UC (Ho Index)

> Ho 2004 IV-Steroid Day-3 Score for Severe UC (Ho Index) 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 Ho 2004 day-3 intravenous steroid failure score (0–9) for severe ulcerative colitis and returns the predicted colectomy risk tier.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/ho_index
- 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/ho-2004-iv-steroid-day-3-score-for-severe-uc-ho-index-97bccb72
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_z7eZCkz-Ja41qjpdPzahI

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 ho-2004-iv-steroid-day-3-score-for-severe-uc-ho-index-97bccb72
```

Example prompt: Calculate the Ho 2004 day-3 IV steroid score for a severe UC patient whose mean stool frequency over the first 3 days is 7, who does not have colonic dilatation, and whose serum albumin is 28 g/L.

## When to prefer this

Use this endpoint when you need to compute the Ho 2004 day-3 IV steroid severity score specifically — not the Travis criteria, not Truelove and Witts, and not any colectomy ordering system. Ideal when a clinical agent has already collected mean stool frequency over days 1–3 of IV steroid therapy and a colonic dilatation assessment, and optionally a serum albumin, and needs a validated numeric risk tier to support gastroenterology decision-making in severe UC.

## Known failure modes

- Missing required parameters (mean_stool_frequency or colonic_dilatation) returns a validation error
- Providing both albumin_g_l and albumin_g_dl simultaneously is rejected
- mean_stool_frequency outside range 0–40 may be rejected
- albumin_g_l outside range 10–60 or albumin_g_dl outside 1–6 may be rejected
- Network or payment (x402) failure returns no score

## How this service works

Ho 2004 day-3 IV-steroid score for severe UC (0–9): mean stools (<4 → 0; 4 ≤ x < 6 → 1; 6 ≤ x ≤ 9 → 2; x > 9 → 4), caller-assigned colonic dilatation (+4), albumin <30 g/L (+1; 30 is not low). Failure: 0–1 → 11%, 2–3 → 43%, ≥4 → 85% (ROC ≥4). Not Travis, not Truelove and Witts, not a colectomy order. magent does not count stools, read films, or measure albumin.

## Output

Returns the Ho 2004 total integer score (0–9), the contributing component scores (stool frequency points, colonic dilatation points, albumin points), and the associated colectomy/steroid-failure risk tier: score 0–1 → ~11% failure risk, 2–3 → ~43%, ≥4 → ~85%. The ROC-derived high-risk threshold is ≥4.

## 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": [
      "mean_stool_frequency",
      "colonic_dilatation"
     ],
     "properties": {
      "albumin_g_l": {
       "type": "number",
       "description": "Serum albumin in g/L (10-60). Provide this or albumin_g_dl, not both. Ho 2004 hypoalbuminaemia is <30 g/L (30 is not low). magent does not assay albumin."
      },
      "albumin_g_dl": {
       "type": "number",
       "description": "Serum albumin in g/dL (1-6). Converted as g/L = g/dL × 10. Provide this or albumin_g_l, not both."
      },
      "colonic_dilatation": {
       "type": "boolean",
       "description": "Caller-assigned colonic dilatation (Ho 2004). true scores 4; false scores 0. magent does not read an abdominal film and does not invent a centimetre cutoff."
      },
      "mean_stool_frequency": {
       "type": "number",
       "description": "Mean stool frequency over the first 3 days of IV steroids, as assigned by the caller (number 0-40). Ho 2004: <4 scores 0; 4 ≤ x < 6 scores 1; 6 ≤ x ≤ 9 scores 2; x > 9 scores 4. Exactly 6 and exactly 9 score 2. magent does not count stools."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ho-2004-iv-steroid-day-3-score-for-severe-uc-ho-index-97bccb72/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)