{"uid":"cap_7dPnm97vI1mZ-twETYMH2","slug":"vacs-index-2-0-calculator-tate-2019-4ba88aa6","name":"VACS Index 2.0 Calculator (Tate 2019)","description":"Tate 2019 VACS Index 2.0 (not 1.0): age, CD4, HIV-1 RNA, hemoglobin, caller-assigned FIB-4 and eGFR, hepatitis C, albumin, WBC, and BMI. Appendix Table 1 polynomials. Score scaled so the median profile is 44. Not a 5-year percent (no published S0). magent does not compute FIB-4 or eGFR and does not assign HIV status.","url":"https://api.magentlab.com/api/calc/vacs_2","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":["age","cd4_cells_mm3","hiv_rna_copies_ml","hemoglobin_g_dl","fib4","egfr_ml_min_1_73m2","hepatitis_c","albumin_g_dl","wbc_10e9_l","bmi_kg_m2"],"properties":{"age":{"type":"integer","description":"Age in years (integer 18-120). Tate 2019 Appendix Table 1 censors age at 30-75 and uses the cubic polynomial of (age-50)/5. magent does not assign age."},"fib4":{"type":"number","description":"Caller-assigned FIB-4 (0.1-20). Appendix Table 1 censors at 0.5-7.5. magent does not recompute FIB-4."},"bmi_kg_m2":{"type":"number","description":"Body mass index in kg/m² (10-60). Appendix Table 1 censors at 15-35 and centers at (BMI-25). magent does not compute BMI from height and weight."},"wbc_10e9_l":{"type":"number","description":"White blood count in 10^9/L (0.5-50), equal to k/µL. Appendix Table 1 censors at 2.5-11 and centers at (WBC-5.5). magent does not assay WBC."},"hepatitis_c":{"type":"boolean","description":"Caller-assigned hepatitis C co-infection (Tate 2019). true adds 0.342 to the linear predictor. magent does not diagnose hepatitis C."},"albumin_g_dl":{"type":"number","description":"Serum albumin in g/dL (1-6.5). Appendix Table 1 censors at 2-5 and centers at (albumin-4). magent does not assay albumin."},"cd4_cells_mm3":{"type":"integer","description":"CD4 count in cells/mm³ (integer 1-2000). Appendix Table 1 censors at 0-1000 and uses ln(max(1000-CD4, 1)). magent does not assay CD4."},"hemoglobin_g_dl":{"type":"number","description":"Hemoglobin in g/dL (3-22). Appendix Table 1 censors at 9-16 and centers at (hemoglobin-14). magent does not assay hemoglobin."},"hiv_rna_copies_ml":{"type":"number","description":"HIV-1 RNA in copies/mL (0-10000000). Appendix Table 1 uses log10 copies censored at 1.3-5.0 and centered at (logVL-2). magent does not assay viral load."},"egfr_ml_min_1_73m2":{"type":"number","description":"Caller-assigned eGFR in mL/min/1.73m² (0-200). Appendix Table 1 censors at 0-180 and uses the footnote truncated linear terms at 35, 65, and 115. magent does not compute MDRD or CKD-EPI. Race is not an input."}}}},"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_sFOndxf8Lb5BCoXDJfX1S","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 Veterans Aging Cohort Study (VACS) Index 2.0 mortality risk score for HIV-positive patients using 10 clinical parameters","exampleAgentPrompt":"Calculate the VACS Index 2.0 score for a 58-year-old HIV-positive patient with a CD4 count of 350 cells/mm³, HIV RNA of 200 copies/mL, hemoglobin of 13.5 g/dL, FIB-4 of 1.8, eGFR of 72 mL/min/1.73m², no hepatitis C, albumin of 3.9 g/dL, WBC of 5.2 × 10⁹/L, and BMI of 27 kg/m².","exampleUseCases":[{"title":"HIV clinic mortality risk stratification","prompt":"I need the VACS 2.0 score for a 62-year-old patient: CD4 480 cells/mm³, viral load 50 copies/mL, hemoglobin 12.1 g/dL, FIB-4 of 2.3, eGFR 58, hepatitis C positive, albumin 3.7 g/dL, WBC 4.8, BMI 24."},{"title":"Aging HIV cohort research scoring","prompt":"For a study cohort member aged 71, compute the Tate 2019 VACS Index 2.0: CD4 count 210, HIV RNA 5000 copies/mL, hemoglobin 11.0 g/dL, FIB-4 3.5, eGFR 45, hepatitis C false, albumin 3.2 g/dL, WBC 3.1, BMI 22."},{"title":"Pre-procedure HIV risk assessment","prompt":"Before planning surgery, I want the VACS 2.0 index for a 45-year-old HIV patient — CD4 is 620, viral load undetectable at 20 copies/mL, hemoglobin 14.8, FIB-4 1.1, eGFR 88, no hep C, albumin 4.2, WBC 6.0, BMI 31."}],"resultDescription":"Returns a numeric VACS Index 2.0 score scaled so that the median clinical profile equals 44, derived from Appendix Table 1 polynomial transformations applied to the 10 supplied laboratory and demographic parameters. Higher scores indicate greater mortality risk. The score is not a 5-year survival percentage (no published baseline survival S0 is incorporated).","failureModes":["Missing required query parameter returns an error — all 10 parameters (age, cd4_cells_mm3, hiv_rna_copies_ml, hemoglobin_g_dl, fib4, egfr_ml_min_1_73m2, hepatitis_c, albumin_g_dl, wbc_10e9_l, bmi_kg_m2) must be provided","Out-of-range values are not rejected but are silently censored to the Appendix Table 1 bounds (e.g., age clamped to 30–75, CD4 clamped to 0–1000)","Caller must pre-compute FIB-4 and eGFR; the endpoint does not derive them from sub-components","hepatitis_c must be a boolean; passing a string like 'yes' may cause a parse error","Payment failure (402) if x402 payment header is not supplied or USDC balance is insufficient"],"whenToPreferThis":"Use this endpoint when you have already assembled all 10 VACS 2.0 input variables for an HIV-positive adult and need a fast, reproducible implementation of the Tate 2019 polynomial scoring algorithm. Prefer this over manual calculation to avoid polynomial arithmetic errors and to ensure correct censoring of out-of-range laboratory values. Do not use if you need to derive FIB-4 from AST/ALT/platelets or eGFR from creatinine — those must be pre-computed by the caller.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T06:44:06.786Z","isFirstParty":false}