# REACH-B HCC risk REACH-B Status: LIVE Price: $0.005 USDC `GET /api/calc/reach_b` HTML: https://magentlab.com/docs/reach-b Markdown: https://magentlab.com/docs/reach-b.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum the Yang 2011 REACH-B 17-point score (sex, age 30-65, ALT, HBeAg, HBV DNA copies/mL) and return the published 3-, 5-, and 10-year HCC risk percents. ## When to use When an agent has caller-assigned sex, age 30-65, ALT, HBeAg, and HBV DNA in copies/mL as in Yang 2011, and needs the published non-cirrhotic REVEAL-HBV score and table risks, not an IU/mL conversion and not a cirrhosis instrument. ## When not to use - Not a medical device. - Not a diagnosis of HCC and not a biopsy order. - Yang 2011 derivation excluded cirrhosis. Not for patients with cirrhosis. Not the later modified REACH-B that scores age >=65 as 7. - Age must be 30-65 as in the derivation cohort. magent does not assay ALT or HBV DNA. HBV DNA is copies/mL as published; this tool does not convert IU/mL. - HBV DNA >=1000000 copies/mL scores 4; 100000-999999 scores 5 (Yang 2011 table, non-monotonic). ## Formula ``` REACH-B = sex + age + ALT + HBeAg + HBV DNA copies/mL; female 0, male 2; age 30-34 -> 0, 35-39 -> 1, 40-44 -> 2, 45-49 -> 3, 50-54 -> 4, 55-59 -> 5, 60-65 -> 6; ALT <15 -> 0, 15-44 -> 1, >=45 -> 2; HBeAg positive 2; HBV DNA copies/mL <300 -> 0, 300-9999 -> 0, 10000-99999 -> 3, 100000-999999 -> 5, >=1000000 -> 4; max 17; 3/5/10-year HCC percent from Yang 2011 score table ``` ## Citation [Risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B): development and validation of a predictive score](https://doi.org/10.1016/S1470-2045(11)70077-8) Yang HI, Yuen MF, Chan HL, et al Lancet Oncol. 2011;12(6):568-574 DOI: [10.1016/S1470-2045(11)70077-8](https://doi.org/10.1016/S1470-2045(11)70077-8) ## Worked example ### Female age 30, ALT 14, HBeAg negative, HBV DNA 200 copies/mL Given: `age=30, alt_u_l=14, hbeag_positive=false, hbv_dna_copies_per_ml=200, sex=female` 1. Female -> 0; age 30 (30-34) -> 0; ALT 14 (<15) -> 0; HBeAg false -> 0; HBV DNA 200 (<300) -> 0 2. Score = 0 (max 17); 3/5/10-year HCC risks 0.0 / 0.0 / 0.0. Not a diagnosis. ## Also searched as - REACH-B - REACH-B score - Yang HCC risk score - REVEAL-HBV HCC score - hepatitis B HCC risk - REACH B - Yang 2011 REACH-B - chronic hepatitis B hepatocellular carcinoma risk ## Parameters - `sex` (string, required): female or male. Yang 2011: female scores 0; male scores 2. - `age` (integer, required): Age in years. Yang 2011 derivation 30-65 only: 30-34 scores 0; 35-39 scores 1; 40-44 scores 2; 45-49 scores 3; 50-54 scores 4; 55-59 scores 5; 60-65 scores 6. Age 34 scores 0; 35 scores 1; 65 scores 6. Age outside 30-65 is rejected. This tool does not score age >=65 as 7. - `alt_u_l` (number, required): Alanine aminotransferase in U/L (1-10000). Caller-assigned; magent does not assay ALT. Yang 2011: <15 scores 0; 15-44 scores 1; >=45 scores 2. ALT 14 scores 0; 15 and 44 score 1; 45 scores 2. - `hbeag_positive` (boolean, required): HBeAg positive as assigned by the caller (Yang 2011). true scores 2; false scores 0. magent does not assay HBeAg. - `hbv_dna_copies_per_ml` (integer, required): HBV DNA in copies/mL (integer 0-10000000000). Yang 2011 uses copies/mL, not IU/mL. magent does not assay HBV DNA and does not convert units. <300 scores 0; 300-9999 scores 0; 10000-99999 scores 3; 100000-999999 scores 5; >=1000000 scores 4 (non-monotonic: 10^6 scores 4, 10^5 to 10^6-1 scores 5). ## 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/reach_b` 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": "30", "alt_u_l": "14", "hbeag_positive": "false", "hbv_dna_copies_per_ml": "200", "sex": "female" }, { "age": "30", "alt_u_l": "14", "hbeag_positive": "false", "hbv_dna_copies_per_ml": "200", "sex": "female" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/reach-b Example 200: ```json { "count": 2, "path": "/api/calc/reach_b", "items": [ { "components": [ { "value": "female", "factor": "sex", "points": 0, "present": false }, { "value": 30, "factor": "age", "points": 0, "present": false }, { "value": 14.0, "factor": "alt", "points": 0, "present": false }, { "factor": "hbeag", "points": 0, "present": false }, { "value": 200, "factor": "hbv_dna", "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": "Yang HI, Yuen MF, Chan HL, et al", "doi": "10.1016/S1470-2045(11)70077-8", "id": "yang-2011", "pmid": "21497551", "source": "Lancet Oncol. 2011;12(6):568-574", "title": "Risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B): development and validation of a predictive score" }, "formula": "reach_b", "formula_expression": "REACH-B = sex + age + ALT + HBeAg + HBV DNA copies/mL; female 0, male 2; age 30-34 -> 0, 35-39 -> 1, 40-44 -> 2, 45-49 -> 3, 50-54 -> 4, 55-59 -> 5, 60-65 -> 6; ALT <15 -> 0, 15-44 -> 1, >=45 -> 2; HBeAg positive 2; HBV DNA copies/mL <300 -> 0, 300-9999 -> 0, 10000-99999 -> 3, 100000-999999 -> 5, >=1000000 -> 4; max 17; 3/5/10-year HCC percent from Yang 2011 score table", "age_years": 30, "max_score": 17, "score": 0, "sex": "female", "alt_u_l": 14.0, "hbeag_positive": false, "hbv_dna_copies_per_ml": 200, "risk_10y_percent": 0.0, "risk_3y_percent": 0.0, "risk_5y_percent": 0.0 }, { "components": [ { "value": "female", "factor": "sex", "points": 0, "present": false }, { "value": 30, "factor": "age", "points": 0, "present": false }, { "value": 14.0, "factor": "alt", "points": 0, "present": false }, { "factor": "hbeag", "points": 0, "present": false }, { "value": 200, "factor": "hbv_dna", "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": "Yang HI, Yuen MF, Chan HL, et al", "doi": "10.1016/S1470-2045(11)70077-8", "id": "yang-2011", "pmid": "21497551", "source": "Lancet Oncol. 2011;12(6):568-574", "title": "Risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B): development and validation of a predictive score" }, "formula": "reach_b", "formula_expression": "REACH-B = sex + age + ALT + HBeAg + HBV DNA copies/mL; female 0, male 2; age 30-34 -> 0, 35-39 -> 1, 40-44 -> 2, 45-49 -> 3, 50-54 -> 4, 55-59 -> 5, 60-65 -> 6; ALT <15 -> 0, 15-44 -> 1, >=45 -> 2; HBeAg positive 2; HBV DNA copies/mL <300 -> 0, 300-9999 -> 0, 10000-99999 -> 3, 100000-999999 -> 5, >=1000000 -> 4; max 17; 3/5/10-year HCC percent from Yang 2011 score table", "age_years": 30, "max_score": 17, "score": 0, "sex": "female", "alt_u_l": 14.0, "hbeag_positive": false, "hbv_dna_copies_per_ml": 200, "risk_10y_percent": 0.0, "risk_3y_percent": 0.0, "risk_5y_percent": 0.0 } ] } ``` ## Response fields - `formula` (string): reach_b - `formula_expression` (string): Exact Yang 2011 17-point expression - `score` (integer): REACH-B points; published range 0-17 - `max_score` (integer): 17 (2+6+2+2+5; DNA max is 5, not 4) - `risk_3y_percent` (number): Published 3-year HCC percent for this score (Yang 2011 table). Not a diagnosis. - `risk_5y_percent` (number): Published 5-year HCC percent for this score (Yang 2011 table). Not a diagnosis. - `risk_10y_percent` (number): Published 10-year HCC percent for this score (Yang 2011 table). Not a diagnosis. - `sex` (string): female or male used for the sex points - `age_years` (integer): Age in years used for the age band - `alt_u_l` (number): Caller-assigned ALT in U/L used - `hbeag_positive` (boolean): Caller-assigned HBeAg flag used - `hbv_dna_copies_per_ml` (integer): Caller-assigned HBV DNA in copies/mL used - `components` (array): Per-factor Yang 2011 points - `citation` (object): Yang 2011 Lancet Oncol citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": "female", "factor": "sex", "points": 0, "present": false }, { "value": 30, "factor": "age", "points": 0, "present": false }, { "value": 14.0, "factor": "alt", "points": 0, "present": false }, { "factor": "hbeag", "points": 0, "present": false }, { "value": 200, "factor": "hbv_dna", "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": "Yang HI, Yuen MF, Chan HL, et al", "doi": "10.1016/S1470-2045(11)70077-8", "id": "yang-2011", "pmid": "21497551", "source": "Lancet Oncol. 2011;12(6):568-574", "title": "Risk estimation for hepatocellular carcinoma in chronic hepatitis B (REACH-B): development and validation of a predictive score" }, "formula": "reach_b", "formula_expression": "REACH-B = sex + age + ALT + HBeAg + HBV DNA copies/mL; female 0, male 2; age 30-34 -> 0, 35-39 -> 1, 40-44 -> 2, 45-49 -> 3, 50-54 -> 4, 55-59 -> 5, 60-65 -> 6; ALT <15 -> 0, 15-44 -> 1, >=45 -> 2; HBeAg positive 2; HBV DNA copies/mL <300 -> 0, 300-9999 -> 0, 10000-99999 -> 3, 100000-999999 -> 5, >=1000000 -> 4; max 17; 3/5/10-year HCC percent from Yang 2011 score table", "age_years": 30, "max_score": 17, "score": 0, "sex": "female", "alt_u_l": 14.0, "hbeag_positive": false, "hbv_dna_copies_per_ml": 200, "risk_10y_percent": 0.0, "risk_3y_percent": 0.0, "risk_5y_percent": 0.0 } ``` ## Errors - HTTP 400 `invalid_sex`: sex must be female or male 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_alt`: alt_u_l must be a number from 1 to 10000 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_hbv_dna`: hbv_dna_copies_per_ml must be an integer from 0 to 10000000000 (Yang 2011 copies/mL). Returned before settlement; you are not charged. - HTTP 400 `invalid_reach_b`: age must be 30-65, and each other REACH-B 2011 item must be a published category. 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 - [FIB-4](https://magentlab.com/docs/fib4) — Compute the FIB-4 fibrosis index from age, AST, ALT, and platelets. ## 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.