# Harvey–Bradshaw simple Crohn's activity index (HBI) HBI Status: LIVE Price: $0.005 USDC `GET /api/calc/harvey_bradshaw` HTML: https://magentlab.com/docs/harvey-bradshaw Markdown: https://magentlab.com/docs/harvey-bradshaw.md Not a medical device. Not a diagnosis, dose, or listing recommendation. ## What it computes Sum Harvey 1980 simple-index items (previous-day well-being, abdominal pain, liquid stools, abdominal mass, and one point per listed complication) and return the total. Does not return later remission or activity bands. ## When to use When an agent has already assigned the 1980 letter item integers and complication flags for the previous day and needs the simple index total, not a Crohn's diagnosis, Best 1976 CDAI, or later HBI remission cutoffs. ## When not to use - Not a medical device and not a Crohn's diagnosis or a treatment order. - magent does not examine the patient. Each item and complication flag is caller-assigned. - Items 1–3 (well-being, abdominal pain, liquid stools) are the previous day as in the 1980 letter. This is a one-day simple index, not the Best 1976 CDAI. - The 1980 letter does not define remission or activity bands. magent returns score and max_score only and does not apply later HBI remission cutoffs. ## Formula ``` HBI = well_being + abdominal_pain + liquid_stools + abdominal_mass + 1 per listed complication; Harvey 1980 previous-day items; magent max 48 (liquid_stools clamp 0-30) ``` ## Citation [A simple index of Crohn's-disease activity](https://doi.org/10.1016/s0140-6736(80)92767-1) Harvey RF, Bradshaw JM Lancet. 1980;1(8167):514 DOI: [10.1016/s0140-6736(80)92767-1](https://doi.org/10.1016/s0140-6736(80)92767-1) ## Worked example ### All items 0, all flags false Given: `abdominal_mass=0, abdominal_pain=0, abscess=false, anal_fissure=false, aphthous_ulcers=false, arthralgia=false, erythema_nodosum=false, liquid_stools=0, new_fistula=false, pyoderma_gangrenosum=false, uveitis=false, well_being=0` 1. well_being 0 + abdominal_pain 0 + liquid_stools 0 + abdominal_mass 0 + 0 complications 2. Score = 0 (max 48). No activity band. ### Magent clamp maximum Given: `abdominal_mass=3, abdominal_pain=3, abscess=true, anal_fissure=true, aphthous_ulcers=true, arthralgia=true, erythema_nodosum=true, liquid_stools=30, new_fistula=true, pyoderma_gangrenosum=true, uveitis=true, well_being=4` 1. well_being 4 + abdominal_pain 3 + liquid_stools 30 + abdominal_mass 3 + 8 complications 2. Score = 48 (max 48). Liquid stools 30 is a magent clamp, not a published maximum. ## Also searched as - Harvey-Bradshaw Index - HBI - simple Crohn's activity index - Harvey Bradshaw 1980 - Crohn's disease activity HBI - HBI score - simple CDAI ## Parameters - `well_being` (integer, required): Caller-assigned Harvey 1980 general well-being for the previous day (integer 0-4): 0 very well; 1 slightly below par; 2 poor; 3 very poor; 4 terrible. magent does not examine the patient. - `abdominal_pain` (integer, required): Caller-assigned Harvey 1980 abdominal pain for the previous day (integer 0-3): 0 none; 1 mild; 2 moderate; 3 severe. magent does not examine the patient. - `liquid_stools` (integer, required): Count of liquid stools that day (Harvey 1980; 1 point per stool). Integer 0-30 is a magent clamp, not a published maximum. magent does not examine the patient. - `abdominal_mass` (integer, required): Caller-assigned Harvey 1980 abdominal mass (integer 0-3): 0 none; 1 dubious; 2 definite; 3 definite and tender. magent does not examine the patient. - `arthralgia` (boolean, required): Arthralgia present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `uveitis` (boolean, required): Uveitis present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `erythema_nodosum` (boolean, required): Erythema nodosum present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `aphthous_ulcers` (boolean, required): Aphthous ulcers present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `pyoderma_gangrenosum` (boolean, required): Pyoderma gangrenosum present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `anal_fissure` (boolean, required): Anal fissure present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `new_fistula` (boolean, required): New fistula present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. - `abscess` (boolean, required): Abscess present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient. ## 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/harvey_bradshaw` 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": [ { "abdominal_mass": "0", "abdominal_pain": "0", "abscess": "false", "anal_fissure": "false", "aphthous_ulcers": "false", "arthralgia": "false", "erythema_nodosum": "false", "liquid_stools": "0", "new_fistula": "false", "pyoderma_gangrenosum": "false", "uveitis": "false", "well_being": "0" }, { "abdominal_mass": "0", "abdominal_pain": "0", "abscess": "false", "anal_fissure": "false", "aphthous_ulcers": "false", "arthralgia": "false", "erythema_nodosum": "false", "liquid_stools": "0", "new_fistula": "false", "pyoderma_gangrenosum": "false", "uveitis": "false", "well_being": "0" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/harvey-bradshaw Example 200: ```json { "count": 2, "path": "/api/calc/harvey_bradshaw", "items": [ { "components": [ { "value": 0, "factor": "well_being", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_pain", "points": 0, "present": true }, { "value": 0, "factor": "liquid_stools", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_mass", "points": 0, "present": true }, { "factor": "arthralgia", "points": 0, "present": false }, { "factor": "uveitis", "points": 0, "present": false }, { "factor": "erythema_nodosum", "points": 0, "present": false }, { "factor": "aphthous_ulcers", "points": 0, "present": false }, { "factor": "pyoderma_gangrenosum", "points": 0, "present": false }, { "factor": "anal_fissure", "points": 0, "present": false }, { "factor": "new_fistula", "points": 0, "present": false }, { "factor": "abscess", "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": "Harvey RF, Bradshaw JM", "doi": "10.1016/s0140-6736(80)92767-1", "id": "harvey-bradshaw-1980", "pmid": "6102236", "source": "Lancet. 1980;1(8167):514", "title": "A simple index of Crohn's-disease activity" }, "formula": "harvey_bradshaw", "formula_expression": "HBI = well_being + abdominal_pain + liquid_stools + abdominal_mass + 1 per listed complication; Harvey 1980 previous-day items; magent max 48 (liquid_stools clamp 0-30)", "max_score": 48, "score": 0, "abdominal_mass": 0, "abdominal_pain": 0, "abscess": false, "anal_fissure": false, "aphthous_ulcers": false, "arthralgia": false, "erythema_nodosum": false, "liquid_stools": 0, "new_fistula": false, "pyoderma_gangrenosum": false, "uveitis": false, "well_being": 0 }, { "components": [ { "value": 0, "factor": "well_being", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_pain", "points": 0, "present": true }, { "value": 0, "factor": "liquid_stools", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_mass", "points": 0, "present": true }, { "factor": "arthralgia", "points": 0, "present": false }, { "factor": "uveitis", "points": 0, "present": false }, { "factor": "erythema_nodosum", "points": 0, "present": false }, { "factor": "aphthous_ulcers", "points": 0, "present": false }, { "factor": "pyoderma_gangrenosum", "points": 0, "present": false }, { "factor": "anal_fissure", "points": 0, "present": false }, { "factor": "new_fistula", "points": 0, "present": false }, { "factor": "abscess", "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": "Harvey RF, Bradshaw JM", "doi": "10.1016/s0140-6736(80)92767-1", "id": "harvey-bradshaw-1980", "pmid": "6102236", "source": "Lancet. 1980;1(8167):514", "title": "A simple index of Crohn's-disease activity" }, "formula": "harvey_bradshaw", "formula_expression": "HBI = well_being + abdominal_pain + liquid_stools + abdominal_mass + 1 per listed complication; Harvey 1980 previous-day items; magent max 48 (liquid_stools clamp 0-30)", "max_score": 48, "score": 0, "abdominal_mass": 0, "abdominal_pain": 0, "abscess": false, "anal_fissure": false, "aphthous_ulcers": false, "arthralgia": false, "erythema_nodosum": false, "liquid_stools": 0, "new_fistula": false, "pyoderma_gangrenosum": false, "uveitis": false, "well_being": 0 } ] } ``` ## Response fields - `formula` (string): harvey_bradshaw - `formula_expression` (string): Exact expression used - `score` (integer): Harvey 1980 simple-index points; magent clamp 0-48 - `max_score` (integer): Always 48 (4+3+30+3+8 magent clamp). Not a published stool maximum. - `well_being` (integer): Caller-assigned well-being 0-4 - `abdominal_pain` (integer): Caller-assigned abdominal pain 0-3 - `liquid_stools` (integer): Liquid stool count that day (magent clamp 0-30) - `abdominal_mass` (integer): Caller-assigned abdominal mass 0-3 - `arthralgia` (boolean): Arthralgia flag; 1 point if true - `uveitis` (boolean): Uveitis flag; 1 point if true - `erythema_nodosum` (boolean): Erythema nodosum flag; 1 point if true - `aphthous_ulcers` (boolean): Aphthous ulcers flag; 1 point if true - `pyoderma_gangrenosum` (boolean): Pyoderma gangrenosum flag; 1 point if true - `anal_fissure` (boolean): Anal fissure flag; 1 point if true - `new_fistula` (boolean): New fistula flag; 1 point if true - `abscess` (boolean): Abscess flag; 1 point if true - `components` (array): Per-item points - `citation` (object): Harvey and Bradshaw Lancet 1980 citation - `disclaimer` (string): Not-a-device notice ## Example JSON Frozen fixture. Not a live lookup. ```json { "components": [ { "value": 0, "factor": "well_being", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_pain", "points": 0, "present": true }, { "value": 0, "factor": "liquid_stools", "points": 0, "present": true }, { "value": 0, "factor": "abdominal_mass", "points": 0, "present": true }, { "factor": "arthralgia", "points": 0, "present": false }, { "factor": "uveitis", "points": 0, "present": false }, { "factor": "erythema_nodosum", "points": 0, "present": false }, { "factor": "aphthous_ulcers", "points": 0, "present": false }, { "factor": "pyoderma_gangrenosum", "points": 0, "present": false }, { "factor": "anal_fissure", "points": 0, "present": false }, { "factor": "new_fistula", "points": 0, "present": false }, { "factor": "abscess", "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": "Harvey RF, Bradshaw JM", "doi": "10.1016/s0140-6736(80)92767-1", "id": "harvey-bradshaw-1980", "pmid": "6102236", "source": "Lancet. 1980;1(8167):514", "title": "A simple index of Crohn's-disease activity" }, "formula": "harvey_bradshaw", "formula_expression": "HBI = well_being + abdominal_pain + liquid_stools + abdominal_mass + 1 per listed complication; Harvey 1980 previous-day items; magent max 48 (liquid_stools clamp 0-30)", "max_score": 48, "score": 0, "abdominal_mass": 0, "abdominal_pain": 0, "abscess": false, "anal_fissure": false, "aphthous_ulcers": false, "arthralgia": false, "erythema_nodosum": false, "liquid_stools": 0, "new_fistula": false, "pyoderma_gangrenosum": false, "uveitis": false, "well_being": 0 } ``` ## Errors - HTTP 400 `invalid_hbi`: well_being 0-4, abdominal_pain 0-3, and abdominal_mass 0-3 (Harvey 1980). Returned before settlement; you are not charged. - HTTP 400 `invalid_liquid_stools`: liquid_stools must be an integer from 0 to 30 (Harvey 1980 count; magent clamp). 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 - [PUCAI](https://magentlab.com/docs/pucai) — Sum six caller-assigned Turner 2007 PUCAI item points and return the published total (max 85) with activity band. ## 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.