{"uid":"cap_Dsi1P9LjAnLuROx5KQtD7","slug":"das28-esr-calculator-prevoo-1995-9383a97b","name":"DAS28-ESR Calculator (Prevoo 1995)","description":"Prevoo 1995 DAS28-ESR: 0.56*sqrt(tjc28) + 0.28*sqrt(sjc28) + 0.70*ln(esr_mm_h) + 0.014*gh (0-100 mm VAS, not 0-10 CDAI/SDAI). Caller-assigned 28-joint counts 0-28; ESR strictly >0 (typical 1-150). magent does not count joints or assay ESR. Score only; Prevoo 1995 does not publish later EULAR 2.6/3.2/5.1 cutoffs. Not SDAI, not CDAI, not DAS28-CRP. Not a rheumatoid arthritis diagnosis.","url":"https://api.magentlab.com/api/calc/das28_esr","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":["tjc28","sjc28","esr_mm_h","gh"],"properties":{"gh":{"type":"number","description":"Caller-assigned patient general health on a 0-100 mm VAS (Prevoo 1995). Number 0-100. Not 0-10 CDAI/SDAI centimetres. magent does not examine the patient."},"sjc28":{"type":"integer","description":"Caller-assigned swollen joint count on the 28-joint set (Prevoo 1995). Integer 0-28. magent does not count joints."},"tjc28":{"type":"integer","description":"Caller-assigned tender joint count on the 28-joint set (Prevoo 1995). Integer 0-28. magent does not count joints."},"esr_mm_h":{"type":"number","description":"Caller-assigned erythrocyte sedimentation rate in mm/h. Strictly >0 (typical 1-150 magent clamp). Natural log in the formula. magent does not assay ESR."}}}},"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_5Tw5jWyjQGRhIGVyrXAFI","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 DAS28-ESR score for rheumatoid arthritis disease activity using the Prevoo 1995 formula from tender joint count, swollen joint count, ESR, and general health VAS.","exampleAgentPrompt":"Calculate the DAS28-ESR score for a patient with 8 tender joints, 4 swollen joints out of 28, an ESR of 45 mm/h, and a general health VAS of 60 out of 100.","exampleUseCases":[{"title":"Monitoring RA treatment response","prompt":"My RA patient has 5 tender joints, 3 swollen joints, an ESR of 30 mm/h, and rates their general health at 40 on the 0-100 VAS — can you compute their DAS28-ESR score so I can track whether the new biologic is working?"},{"title":"Baseline disease activity at diagnosis","prompt":"I need a DAS28-ESR for a newly diagnosed rheumatoid arthritis patient: tender joint count 12, swollen joint count 9, ESR 78 mm/h, and patient global health VAS 72 out of 100."},{"title":"Pre-visit clinical summary calculation","prompt":"Before my rheumatology clinic tomorrow, calculate the DAS28-ESR for a patient whose nurse recorded 2 tender joints, 1 swollen joint, ESR of 15 mm/h, and a general health score of 20 on the 100mm scale."}],"resultDescription":"Returns the numeric DAS28-ESR score computed as 0.56×√(tjc28) + 0.28×√(sjc28) + 0.70×ln(esr_mm_h) + 0.014×gh. This is a continuous numeric value reflecting rheumatoid arthritis disease activity per the Prevoo 1995 formula. Note: EULAR remission/low/moderate/high activity cutoffs (2.6/3.2/5.1) are not part of the Prevoo 1995 publication and are not returned by this endpoint.","failureModes":["esr_mm_h ≤ 0 will cause an error since the formula requires a natural log of a strictly positive value","tjc28 or sjc28 outside 0-28 integer range may be rejected or produce out-of-range scores","gh outside 0-100 range may produce invalid scores","Missing any of the four required query parameters returns an error","Confusing gh units (0-10 cm CDAI/SDAI scale vs required 0-100 mm VAS) will silently produce incorrect scores"],"whenToPreferThis":"Use this endpoint when you need the ESR-based DAS28 score specifically (Prevoo 1995 formula). Choose this over DAS28-CRP when the available inflammatory marker is erythrocyte sedimentation rate rather than C-reactive protein. Do not use if you need SDAI, CDAI, or DAS28-CRP; those use different formulas and inputs. This is purely a computation endpoint — the caller must supply pre-assessed clinical values (joint counts, ESR, patient global health VAS).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T07:05:05.821Z","isFirstParty":false}