{"uid":"cap_7s7HN1EtUo2IALksxkKFM","slug":"asdas-crp-calculator-van-der-heijde-2009-f1e34714","name":"ASDAS-CRP Calculator (van der Heijde 2009)","description":"van der Heijde 2009 ASDAS-CRP: 0.12*back pain + 0.06*morning stiffness duration + 0.11*patient global + 0.07*peripheral pain/swelling + 0.58*ln(CRP+1). BASDAI 0-10 items and CRP in mg/L. ASAS selected the CRP version as preferred. magent does not examine the patient or assay CRP. Not ASDAS-ESR. Not BASDAI total. Does not apply Machado 2011 1.3/2.1/3.5 activity cuts. Not a diagnosis or biologic order.","url":"https://api.magentlab.com/api/calc/asdas_crp","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["back_pain","morning_stiffness_duration","patient_global","peripheral_pain_swelling","crp_mg_l"],"properties":{"crp_mg_l":{"type":"number","description":"Caller-assigned C-reactive protein in mg/L (van der Heijde 2009; not mg/dL). Number 0-500 is a magent clamp. The 2009 papers do not floor CRP at 2 mg/L. magent does not assay CRP."},"back_pain":{"type":"number","description":"Caller-assigned total back pain on a 0-10 VAS or NRS (van der Heijde 2009; BASDAI question 2, neck/back/hip pain). Number 0-10. magent does not examine the patient."},"patient_global":{"type":"number","description":"Caller-assigned patient global assessment of disease activity on a 0-10 VAS or NRS (van der Heijde 2009). Number 0-10. magent does not examine the patient."},"peripheral_pain_swelling":{"type":"number","description":"Caller-assigned peripheral pain/swelling on a 0-10 VAS or NRS (van der Heijde 2009; BASDAI question 3, joints other than neck/back/hips). Number 0-10. magent does not examine the patient."},"morning_stiffness_duration":{"type":"number","description":"Caller-assigned duration of morning stiffness on a 0-10 VAS or NRS (van der Heijde 2009; BASDAI question 6). Number 0-10, not hours. magent does not examine the patient."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_v4jh7clXRCzFcKMA7g5Ji","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the Ankylosing Spondylitis Disease Activity Score using CRP (ASDAS-CRP) from five caller-supplied clinical inputs using the van der Heijde 2009 formula.","exampleAgentPrompt":"Calculate the ASDAS-CRP score for a patient with back pain 6/10, morning stiffness duration 4/10, patient global 7/10, peripheral pain/swelling 2/10, and a CRP of 18 mg/L.","exampleUseCases":[{"title":"Rheumatology clinic disease activity tracking","prompt":"My ankylosing spondylitis patient today has back pain 5/10, morning stiffness 3/10, patient global 6/10, peripheral pain 1/10, and their CRP came back at 12 mg/L — can you compute their ASDAS-CRP score?"},{"title":"Biologic therapy response monitoring","prompt":"Before and after starting adalimumab, I want to track disease activity. Right now the patient scores back pain 8, morning stiffness 7, global 8, peripheral 4, CRP 42 mg/L — what's their ASDAS-CRP?"},{"title":"Automated EHR-integrated scoring","prompt":"Pull the latest BASDAI component scores and CRP from the chart — back pain 4, morning stiffness duration 5, patient global 5, peripheral pain 2, CRP 8 mg/L — and give me the ASDAS-CRP so I can document disease activity today."}],"resultDescription":"Returns a numeric ASDAS-CRP value computed as 0.12×back_pain + 0.06×morning_stiffness_duration + 0.11×patient_global + 0.07×peripheral_pain_swelling + 0.58×ln(CRP+1), representing overall axial spondyloarthritis disease activity. Does not apply Machado 2011 activity category cut-points or produce a diagnosis.","failureModes":["Missing required query parameters (back_pain, morning_stiffness_duration, patient_global, peripheral_pain_swelling, crp_mg_l) returns an error","CRP value outside 0–500 mg/L range is clamped by magent","Non-numeric values for any parameter cause a validation error","Payment failure (x402) if USDC balance is insufficient"],"whenToPreferThis":"Choose this endpoint when you need the ASAS-preferred CRP-based ASDAS formula (van der Heijde 2009) specifically — not ASDAS-ESR, not the BASDAI total, and not Machado 2011 cut-point categorization. Ideal when CRP is available in mg/L and you want a reproducible, formula-exact computation without relying on local code.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:53:20.414Z","isFirstParty":false}