The Effects of Different ART Eligibility Strategies on HIV-Related Mortality and Incidence John Stover, Carel Pretorius, Lori Bollinger Futures Institute July 23, 2012 XIX International AIDS Conference, July 22-27, 2012, Washington, DC

Adult CD4 Model New Infections> <50 On ART AIDS Death > <50 λ7λ7 λ6λ6 λ5λ5 λ4λ4 λ3λ3 λ2λ2 λ1λ1 μ1μ1 μ2μ2 μ3μ3 μ4μ4 μ5μ5 μ6μ6 μ7μ7 α1α1 α2α2 α3α3 α4α4 α5α5 α6α6 α7α7 c1c1 c2c2 c3c3 c4c4 c5c5 c6c6 c7c7 2 μ = HIV-related mortality rate; λ = Rate of progression to lower CD4 counts; c = Rate of initiating ART; α = HIV-related mortality rate while on ART

Progression (λ) CD4 CategoryProportion Progressing Annually Duration in State (years) Annual Rate of Decline (cells/μl) >500 -> > > > > > < λ values are determined by fitting to ALPHA network patterns of progression to AIDS death and distribution of HIV+ population not on ART by CD4 count from Kenya AIS 2007 subject to the constraint that the annual decline should be constant across CD4 categories.

Effect of ART on Transmission Primary Infection> <50 4 On ART HIV+ Population by CD4 Category Transmission Multiplier 8 – – 0.2 Combined effect changes with distribution of HIV+ by CD4 count and ART

Scenarios to Model Eligibility for treatment – CD4 count: <350 <500 All – Pregnant women: <500 All – HIV+/TB+ – Discordant couples Key outputs – New infections – Number on ART – Costs of treatment – PY of Tx per IA – PY of Tx per death averted – Life years gained – $/IA, $/DA, $/LYG 5

Person-Years of Treatment per Infection Averted ( ) 6

Additional Cost in Millions of US$ ( ) 7

Cost per Infection Averted ( ) 8

Conclusions Earlier initiation of ART will reduce HIV-related mortality and incidence Cost per infection averted rises at higher CD4 count thresholds A major challenge to implementing very early initiation will be findings all those eligible The most urgent need is to reach all those with CD4 counts under 350 9