ToolsCalculators
Veterans Aging Cohort Study (VACS) 1.0 Index
All-cause mortality risk in patients with HIV (or HIV/HCV coinfection).
Veterans Aging Cohort Study (VACS) 1.0 Index
Age
years
CD4 count
cells/µL
HIV-1 RNA (viral load)
copies/mL
Hemoglobin
AST (aspartate aminotransferase)
U/L
ALT (alanine aminotransferase)
U/L
Platelet count
×10⁹/L
Serum creatinine
Sex
Race
Used only for the eGFR (MDRD) calculation.
Hepatitis C seropositive
Complete the fields above to see the result.
When to use
- Estimating all-cause mortality risk in adults with HIV (validated in HIV/HCV coinfection) already established on or starting antiretroviral therapy.
- Comparing physiologic burden of disease over time or between patients as an adjunct to traditional HIV markers.
Formula
Sum of points: Age <50=0, 50-64=12, ≥65=27. CD4 ≥500=0, 200-499=6, 100-199=10, 50-99=28, <50=29. HIV-1 RNA <500=0, 500-100,000=7, >100,000=14. Hemoglobin ≥14=0, 12-13.9=10, 10-11.9=22, <10=38. FIB-4 <1.45=0, 1.45-3.25=6, >3.25=25 (FIB-4 = age × AST / (platelets × √ALT)). eGFR ≥60=0, 45-59.9=6, 30-44.9=8, <30=26 (four-variable MDRD: 186.3 × creatinine^-1.154 × age^-0.203 × 0.742 [female] × 1.21 [Black]). Hepatitis C positive = +5.
Pearls and pitfalls
- A 'Restricted Index' using only age, CD4 count, and HIV-1 RNA has slightly lower discrimination but needs no laboratory panel beyond routine HIV monitoring.
- Validated across six independent ART Cohort Collaboration cohorts with better discrimination than age and traditional HIV markers alone (c-statistic ~0.78-0.82).