# DECAF score DECAF Status: LIVE Price: $0.005 USDC `GET /api/calc/decaf` HTML: https://magentlab.com/docs/decaf Markdown: https://magentlab.com/docs/decaf.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum Steer 2012 DECAF points from extended MRC dyspnoea, eosinophils, chest radiograph consolidation, arterial pH, and atrial fibrillation. ## When to use When an agent needs the published Steer 2012 DECAF total and band and must not invent an early-discharge or escalation decision or a mortality percent. ## When not to use - Not a medical device. Not an early-discharge or escalation protocol. Bands follow Steer 2012 (0-1 / 2 / 3-6) and do not include mortality percents. - eMRCD is the caller-assigned extended MRC grade 1-4, 5a, or 5b. magent does not interview the patient. - Consolidation and atrial fibrillation are caller-assigned flags. magent does not interpret the chest radiograph or ECG. ## Formula ``` DECAF = emrcd_points + eosinopenia + consolidation + acidemia + atrial_fibrillation; eMRCD 1-4 -> 0, 5a -> 1, 5b -> 2; eosinophils_10e9_l < 0.05 -> 1 (0.05 does not score); consolidation true -> 1; arterial_ph < 7.30 -> 1 (7.30 does not score); atrial_fibrillation true -> 1; bands 0-1 / 2 / 3-6; max 6 ``` ## Citation [The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease](https://doi.org/10.1136/thoraxjnl-2012-202103) Steer J, Gibson J, Bourke SC Thorax. 2012;67(11):970-976 DOI: [10.1136/thoraxjnl-2012-202103](https://doi.org/10.1136/thoraxjnl-2012-202103) ## Worked example ### No DECAF points (band 0-1) Given: `arterial_ph=7.40, atrial_fibrillation=false, consolidation=false, emrcd=1-4, eosinophils_10e9_l=0.10` 1. eMRCD 1-4 → 0; eosinophils 0.10 ≥0.05 → 0; no consolidation → 0; pH 7.40 ≥7.30 → 0; no AF → 0 2. Score = 0; band 0-1 ### Maximum points (band 3-6) Given: `arterial_ph=7.20, atrial_fibrillation=true, consolidation=true, emrcd=5b, eosinophils_10e9_l=0.02` 1. eMRCD 5b → 2; eosinophils 0.02 <0.05 → 1; consolidation → 1; pH 7.20 <7.30 → 1; AF → 1 2. Score = 6; band 3-6 ## Also searched as - DECAF score - Steer DECAF - COPD exacerbation DECAF - eMRCD DECAF - extended MRC DECAF - dyspnoea eosinopenia consolidation - COPD hospital mortality score ## Parameters - `emrcd` (string, required): Steer 2012 extended MRC dyspnoea as assigned by the caller. 1-4 scores 0; 5a scores 1; 5b scores 2. magent does not interview the patient. - `eosinophils_10e9_l` (number, required): Blood eosinophil count ×10^9/L (0-5). Steer 2012: <0.05 scores 1; 0.05 does not score. - `consolidation` (boolean, required): Chest radiograph consolidation as assigned by the caller (Steer 2012 C). true or false. 1 point if true. magent does not interpret radiographs. - `arterial_ph` (number, required): Arterial pH (6.80-7.80). Steer 2012: <7.30 scores 1; 7.30 does not score. - `atrial_fibrillation` (boolean, required): Atrial fibrillation as assigned by the caller (Steer 2012 F). true or false. 1 point if true. magent does not interpret the ECG. ## 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/decaf` 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": [ { "arterial_ph": "7.40", "atrial_fibrillation": "false", "consolidation": "false", "emrcd": "1-4", "eosinophils_10e9_l": "0.10" }, { "arterial_ph": "7.40", "atrial_fibrillation": "false", "consolidation": "false", "emrcd": "1-4", "eosinophils_10e9_l": "0.10" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/decaf Example 200: ```json { "count": 2, "path": "/api/calc/decaf", "items": [ { "components": [ { "value": "1-4", "factor": "emrcd", "points": 0, "present": false }, { "value": 0.1, "factor": "eosinopenia", "points": 0, "present": false }, { "factor": "consolidation", "points": 0, "present": false }, { "value": 7.4, "factor": "acidemia", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "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.", "citation": { "authors": "Steer J, Gibson J, Bourke SC", "doi": "10.1136/thoraxjnl-2012-202103", "id": "steer-2012", "pmid": "22895999", "source": "Thorax. 2012;67(11):970-976", "title": "The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease" }, "formula": "decaf", "formula_expression": "DECAF = emrcd_points + eosinopenia + consolidation + acidemia + atrial_fibrillation; eMRCD 1-4 -> 0, 5a -> 1, 5b -> 2; eosinophils_10e9_l < 0.05 -> 1 (0.05 does not score); consolidation true -> 1; arterial_ph < 7.30 -> 1 (7.30 does not score); atrial_fibrillation true -> 1; bands 0-1 / 2 / 3-6; max 6", "max_score": 6, "score": 0, "atrial_fibrillation": false, "arterial_ph": 7.4, "consolidation": false, "decaf_band": "0-1", "emrcd": "1-4", "eosinophils_10e9_l": 0.1 }, { "components": [ { "value": "1-4", "factor": "emrcd", "points": 0, "present": false }, { "value": 0.1, "factor": "eosinopenia", "points": 0, "present": false }, { "factor": "consolidation", "points": 0, "present": false }, { "value": 7.4, "factor": "acidemia", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "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.", "citation": { "authors": "Steer J, Gibson J, Bourke SC", "doi": "10.1136/thoraxjnl-2012-202103", "id": "steer-2012", "pmid": "22895999", "source": "Thorax. 2012;67(11):970-976", "title": "The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease" }, "formula": "decaf", "formula_expression": "DECAF = emrcd_points + eosinopenia + consolidation + acidemia + atrial_fibrillation; eMRCD 1-4 -> 0, 5a -> 1, 5b -> 2; eosinophils_10e9_l < 0.05 -> 1 (0.05 does not score); consolidation true -> 1; arterial_ph < 7.30 -> 1 (7.30 does not score); atrial_fibrillation true -> 1; bands 0-1 / 2 / 3-6; max 6", "max_score": 6, "score": 0, "atrial_fibrillation": false, "arterial_ph": 7.4, "consolidation": false, "decaf_band": "0-1", "emrcd": "1-4", "eosinophils_10e9_l": 0.1 } ] } ``` ## Response fields - `formula` (string): decaf - `formula_expression` (string): Exact Steer 2012 expression - `score` (integer): DECAF points 0-6 - `max_score` (integer): Always 6 - `decaf_band` (string): Steer 2012 band 0-1 (low), 2 (moderate), or 3-6 (high). A band, not a mortality percent. - `emrcd` (string): Caller-assigned eMRCD: 1-4, 5a, or 5b - `eosinophils_10e9_l` (number): Eosinophil count ×10^9/L used - `consolidation` (boolean): Caller-assigned chest radiograph consolidation - `arterial_ph` (number): Arterial pH used - `atrial_fibrillation` (boolean): Caller-assigned atrial fibrillation - `components` (array): Per-factor points for emrcd, eosinopenia, consolidation, acidemia, and AF - `citation` (object): Steer et al. Thorax 2012 citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": "1-4", "factor": "emrcd", "points": 0, "present": false }, { "value": 0.1, "factor": "eosinopenia", "points": 0, "present": false }, { "factor": "consolidation", "points": 0, "present": false }, { "value": 7.4, "factor": "acidemia", "points": 0, "present": false }, { "factor": "atrial_fibrillation", "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.", "citation": { "authors": "Steer J, Gibson J, Bourke SC", "doi": "10.1136/thoraxjnl-2012-202103", "id": "steer-2012", "pmid": "22895999", "source": "Thorax. 2012;67(11):970-976", "title": "The DECAF Score: predicting hospital mortality in exacerbations of chronic obstructive pulmonary disease" }, "formula": "decaf", "formula_expression": "DECAF = emrcd_points + eosinopenia + consolidation + acidemia + atrial_fibrillation; eMRCD 1-4 -> 0, 5a -> 1, 5b -> 2; eosinophils_10e9_l < 0.05 -> 1 (0.05 does not score); consolidation true -> 1; arterial_ph < 7.30 -> 1 (7.30 does not score); atrial_fibrillation true -> 1; bands 0-1 / 2 / 3-6; max 6", "max_score": 6, "score": 0, "atrial_fibrillation": false, "arterial_ph": 7.4, "consolidation": false, "decaf_band": "0-1", "emrcd": "1-4", "eosinophils_10e9_l": 0.1 } ``` ## Errors - HTTP 400 `invalid_emrcd`: emrcd must be 1-4, 5a, or 5b (Steer 2012 extended MRC dyspnoea). Returned before settlement; you are not charged. - HTTP 400 `invalid_eosinophils`: eosinophils_10e9_l must be a number from 0 to 5 (Steer 2012). Returned before settlement; you are not charged. - HTTP 400 `invalid_arterial_ph`: arterial_ph must be a number from 6.80 to 7.80. Returned before settlement; you are not charged. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false 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 - [BODE](https://magentlab.com/docs/bode) — Sum Celli 2004 BODE points from BMI, FEV1 percent predicted, MMRC dyspnea, and 6-minute walk distance. - [GAP index](https://magentlab.com/docs/gap-index) — Sum Ley 2012 GAP index points from sex, age, FVC percent predicted, and DLCO percent predicted or cannot-perform. - [CURB-65](https://magentlab.com/docs/curb65) — Compute the CURB-65 community-acquired pneumonia severity score from age and discrete flags. ## 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 echoing accepted, payload, and extensions when present). - 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. - 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.