# Urine protein/creatinine ratio (Ginsberg 1983)

Urine PCR

Status: WEDGE
Price: $0.005 USDC
`GET /api/calc/urine_pcr`
HTML: https://magentlab.com/docs/urine-pcr
Markdown: https://magentlab.com/docs/urine-pcr.md

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

## What it computes

Compute the Ginsberg 1983 urine protein/creatinine ratio (mg/mg) from a single-void urine protein and urine creatinine, and return that rounded ratio as estimated_g_day (numeric estimate of 24-h protein g/day).

## When to use

When an agent has a single-void urine protein and urine creatinine and must not invent a 24-h collection or an albumin/creatinine (ACR) result.

## When not to use

- Not a medical device. Ginsberg 1983 bands are published protein/creatinine cut-points (ratio <0.2 within normal limits; ratio >3.5 nephrotic-range), not a diagnosis of nephrotic syndrome.
- magent does not collect urine. This is not a 24-hour urine collection. estimated_g_day equals the rounded ratio as a numeric estimate of 24-h protein g/day from Ginsberg 1983, not a measured collection.
- Not ACR (albumin/creatinine). This calculator uses total urine protein, not albumin.
- Exact ratios 0.2 and 3.5 are the mid band (the paper says less than 0.2 and more than 3.5).

## Formula

```
protein_creatinine_ratio = urine_protein_mg_dl / urine_creatinine_mg_dl
```

## Citation

[Use of single voided urine samples to estimate quantitative proteinuria.](https://doi.org/10.1056/nejm198312223092503)
Ginsberg JM, Chang BS, Matarese RA, Garella S
N Engl J Med. 1983;309(25):1543-1546
DOI: [10.1056/nejm198312223092503](https://doi.org/10.1056/nejm198312223092503)

## Worked example

### Protein 100 mg/dL, creatinine 100 mg/dL

Given: `urine_creatinine_mg_dl=100, urine_protein_mg_dl=100`

1. protein_creatinine_ratio = 100 / 100 = 1.0 (mg/mg, rounded to 2 decimals)
2. estimated_g_day = 1.0 (Ginsberg 1983 numeric estimate of 24-h protein g/day)
3. Ginsberg band: not <0.2 and not >3.5 → 0_2_to_3_5


## Also searched as

- urine protein creatinine ratio
- protein/creatinine ratio
- urine PCR
- UPCR
- spot urine protein
- Ginsberg proteinuria
- spot proteinuria ratio
- urine protein/creatinine

## Parameters

- `urine_protein_mg_dl` (number, required): Urine total protein in mg/dL (0.1-2000). Total protein, not albumin.
- `urine_creatinine_mg_dl` (number, optional): Urine creatinine in mg/dL (1-500). Provide this or urine_creatinine_umol_l.
- `urine_creatinine_umol_l` (number, optional): Urine creatinine in µmol/L (88-44210). Converted as mg/dL = µmol/L / 88.42.

## 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.

Method: `POST /api/calc/urine_pcr`
Max items: 25
Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic)
Status: 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:

```json
{
  "items": [
    {
      "urine_creatinine_mg_dl": "100",
      "urine_protein_mg_dl": "100"
    },
    {
      "urine_creatinine_mg_dl": "100",
      "urine_protein_mg_dl": "100"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/urine-pcr

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/urine_pcr",
  "items": [
    {
      "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": "Ginsberg JM, Chang BS, Matarese RA, Garella S",
        "doi": "10.1056/nejm198312223092503",
        "id": "ginsberg-1983",
        "pmid": "6656849",
        "source": "N Engl J Med. 1983;309(25):1543-1546",
        "title": "Use of single voided urine samples to estimate quantitative proteinuria."
      },
      "formula": "ginsberg",
      "formula_expression": "protein_creatinine_ratio = urine_protein_mg_dl / urine_creatinine_mg_dl",
      "urine_creatinine_mg_dl": 100.0,
      "estimated_g_day": 1.0,
      "ginsberg_band": "0_2_to_3_5",
      "protein_creatinine_ratio": 1.0,
      "urine_protein_mg_dl": 100.0
    },
    {
      "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": "Ginsberg JM, Chang BS, Matarese RA, Garella S",
        "doi": "10.1056/nejm198312223092503",
        "id": "ginsberg-1983",
        "pmid": "6656849",
        "source": "N Engl J Med. 1983;309(25):1543-1546",
        "title": "Use of single voided urine samples to estimate quantitative proteinuria."
      },
      "formula": "ginsberg",
      "formula_expression": "protein_creatinine_ratio = urine_protein_mg_dl / urine_creatinine_mg_dl",
      "urine_creatinine_mg_dl": 100.0,
      "estimated_g_day": 1.0,
      "ginsberg_band": "0_2_to_3_5",
      "protein_creatinine_ratio": 1.0,
      "urine_protein_mg_dl": 100.0
    }
  ]
}
```

## Response fields

- `formula` (string): ginsberg
- `formula_expression` (string): Exact expression used
- `urine_protein_mg_dl` (number): Urine total protein in mg/dL
- `urine_creatinine_mg_dl` (number): Normalized urine creatinine in mg/dL
- `protein_creatinine_ratio` (number): Protein/creatinine ratio in mg/mg, 2 decimal places
- `estimated_g_day` (number): Numeric estimate of 24-h protein g/day, equal to the rounded ratio (Ginsberg 1983). Not a measured 24-h collection.
- `ginsberg_band` (string): Ginsberg 1983 bands: lt_0_2 (ratio <0.2, within normal limits), gt_3_5 (ratio >3.5, nephrotic-range), or 0_2_to_3_5. Exact 0.2 and 3.5 are mid. Not a diagnosis.
- `citation` (object): NEJM 1983 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "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": "Ginsberg JM, Chang BS, Matarese RA, Garella S",
    "doi": "10.1056/nejm198312223092503",
    "id": "ginsberg-1983",
    "pmid": "6656849",
    "source": "N Engl J Med. 1983;309(25):1543-1546",
    "title": "Use of single voided urine samples to estimate quantitative proteinuria."
  },
  "formula": "ginsberg",
  "formula_expression": "protein_creatinine_ratio = urine_protein_mg_dl / urine_creatinine_mg_dl",
  "urine_creatinine_mg_dl": 100.0,
  "estimated_g_day": 1.0,
  "ginsberg_band": "0_2_to_3_5",
  "protein_creatinine_ratio": 1.0,
  "urine_protein_mg_dl": 100.0
}
```

## Errors

- HTTP 400 `invalid_urine_pcr`: urine_protein_mg_dl must be a number from 0.1 to 2000 (Ginsberg 1983 protein/creatinine ratio). Returned before settlement; you are not charged.
- HTTP 400 `invalid_urine_creatinine`: urine_creatinine_mg_dl (1-500) or urine_creatinine_umol_l (88-44210) is required. Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [FENa](https://magentlab.com/docs/fena) — Compute fractional excretion of sodium from plasma and urine sodium and creatinine using Espinel 1976.
- [FEUrea](https://magentlab.com/docs/feurea) — Compute fractional excretion of urea (FEUN) from BUN, urine urea nitrogen, plasma creatinine, and urine creatinine.

## 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.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.
- offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/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.