# IDMS MDRD eGFR IDMS MDRD eGFR Status: LIVE Price: $0.005 USDC `GET /api/calc/mdrd` HTML: https://magentlab.com/docs/mdrd Markdown: https://magentlab.com/docs/mdrd.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Compute IDMS-traceable 4-variable MDRD eGFR in mL/min/1.73m2 from standardized creatinine, adult age, sex, and caller-assigned Black as used in Levey 2006. ## When to use When an agent must apply the published IDMS 4-variable MDRD equation rather than invent kidney function, including the Levey 2006 Black coefficient as assigned by the caller. magent does not assign race. ## When not to use - IDMS-traceable 4-variable MDRD (Levey 2006). Not the 1999 conventional 186 equation. Not CKD-EPI 2021 (egfr). - black is caller-assigned as used in Levey 2006; magent does not assign race. - Adults only (age 18-120). Not a pediatric equation. - Not a treatment or dosing recommendation and not a medical device. ## Formula ``` egfr = 175 * scr_mg_dl ** -1.154 * age ** -0.203 * sex_factor * black_factor; sex_factor = 0.742 if female else 1.0; black_factor = 1.212 if black else 1.0; IDMS-traceable 4-variable MDRD; GFR mL/min/1.73m2; Scr mg/dL ``` ## Citation [Using Standardized Serum Creatinine Values in the Modification of Diet in Renal Disease Study Equation for Estimating Glomerular Filtration Rate](https://doi.org/10.7326/0003-4819-145-4-200608150-00004) Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, Kusek JW, Van Lente F Ann Intern Med. 2006;145(4):247-254 DOI: [10.7326/0003-4819-145-4-200608150-00004](https://doi.org/10.7326/0003-4819-145-4-200608150-00004) ## Worked example ### Scr 1.1, age 65, female, black false Given: `age=65, black=false, creatinine_mg_dl=1.1, sex=female` 1. sex_factor=0.742, black_factor=1.0 2. egfr = 175 * 1.1 ** -1.154 * 65 ** -0.203 * 0.742 * 1.0 3. Round to 1 decimal ## Also searched as - MDRD eGFR - IDMS MDRD - 4-variable MDRD - Levey 2006 GFR - Modification of Diet in Renal Disease ## Parameters - `creatinine_mg_dl` (number, optional): Serum creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l. - `creatinine_umol_l` (number, optional): Serum creatinine in µmol/L. Converted as mg/dL = µmol/L / 88.42. IDMS-traceable standardized creatinine as in Levey 2006. - `age` (integer, required): Age in years (18-120). MDRD is for adults. - `sex` (string, required): Sex used by the published equation. female applies 0.742; male does not. - `black` (boolean, required): Caller-assigned Black as used in Levey 2006; magent does not assign race. true applies 1.212. ## 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/mdrd` 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": [ { "age": "65", "black": "false", "creatinine_mg_dl": "1.1", "sex": "female" }, { "age": "65", "black": "false", "creatinine_mg_dl": "1.1", "sex": "female" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/mdrd Example 200: ```json { "count": 2, "path": "/api/calc/mdrd", "items": [ { "black": false, "units": "mL/min/1.73m2", "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": "Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, Kusek JW, Van Lente F", "doi": "10.7326/0003-4819-145-4-200608150-00004", "id": "levey-2006-mdrd", "pmid": "16908729", "source": "Ann Intern Med. 2006;145(4):247-254", "title": "Using Standardized Serum Creatinine Values in the Modification of Diet in Renal Disease Study Equation for Estimating Glomerular Filtration Rate" }, "formula": "mdrd_idms_4var", "formula_expression": "egfr = 175 * scr_mg_dl ** -1.154 * age ** -0.203 * sex_factor * black_factor; sex_factor = 0.742 if female else 1.0; black_factor = 1.212 if black else 1.0; IDMS-traceable 4-variable MDRD; GFR mL/min/1.73m2; Scr mg/dL", "age_years": 65, "creatinine_mg_dl": 1.1, "sex": "female", "egfr_ml_min_1_73m2": 49.8 }, { "black": false, "units": "mL/min/1.73m2", "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": "Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, Kusek JW, Van Lente F", "doi": "10.7326/0003-4819-145-4-200608150-00004", "id": "levey-2006-mdrd", "pmid": "16908729", "source": "Ann Intern Med. 2006;145(4):247-254", "title": "Using Standardized Serum Creatinine Values in the Modification of Diet in Renal Disease Study Equation for Estimating Glomerular Filtration Rate" }, "formula": "mdrd_idms_4var", "formula_expression": "egfr = 175 * scr_mg_dl ** -1.154 * age ** -0.203 * sex_factor * black_factor; sex_factor = 0.742 if female else 1.0; black_factor = 1.212 if black else 1.0; IDMS-traceable 4-variable MDRD; GFR mL/min/1.73m2; Scr mg/dL", "age_years": 65, "creatinine_mg_dl": 1.1, "sex": "female", "egfr_ml_min_1_73m2": 49.8 } ] } ``` ## Response fields - `formula` (string): mdrd_idms_4var - `formula_expression` (string): Exact expression used - `creatinine_mg_dl` (number): Normalized creatinine in mg/dL - `age_years` (integer): Age used in the equation - `sex` (string): female or male - `black` (boolean): Caller-assigned Black as used in Levey 2006; magent does not assign race - `egfr_ml_min_1_73m2` (number): Estimated GFR, 1 decimal place - `units` (string): mL/min/1.73m2 - `citation` (object): Levey 2006 Ann Intern Med citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "black": false, "units": "mL/min/1.73m2", "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": "Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, Kusek JW, Van Lente F", "doi": "10.7326/0003-4819-145-4-200608150-00004", "id": "levey-2006-mdrd", "pmid": "16908729", "source": "Ann Intern Med. 2006;145(4):247-254", "title": "Using Standardized Serum Creatinine Values in the Modification of Diet in Renal Disease Study Equation for Estimating Glomerular Filtration Rate" }, "formula": "mdrd_idms_4var", "formula_expression": "egfr = 175 * scr_mg_dl ** -1.154 * age ** -0.203 * sex_factor * black_factor; sex_factor = 0.742 if female else 1.0; black_factor = 1.212 if black else 1.0; IDMS-traceable 4-variable MDRD; GFR mL/min/1.73m2; Scr mg/dL", "age_years": 65, "creatinine_mg_dl": 1.1, "sex": "female", "egfr_ml_min_1_73m2": 49.8 } ``` ## Errors - HTTP 400 `invalid_creatinine`: creatinine_mg_dl (0.1-20) or creatinine_umol_l (9-1768) is required Returned before settlement; you are not charged. - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_sex`: sex must be female or male Returned before settlement; you are not charged. - HTTP 400 `invalid_mdrd`: MDRD needs IDMS creatinine, adult age, sex, and caller-assigned black as used in Levey 2006. 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 - [CKD-EPI 2021 eGFR](https://magentlab.com/docs/egfr) — Compute race-free CKD-EPI 2021 creatinine eGFR in mL/min/1.73m2. - [Cockcroft–Gault CrCl](https://magentlab.com/docs/crcl) — Compute Cockcroft–Gault creatinine clearance in mL/min using total body weight. ## 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.