CROI 2015 Program and Abstracts

Abstract Listing

Oral Abstracts

1110 The Cost-Effectiveness of Early ART Initiation in South Africa: A Quasi-Experiment Jacob Bor 1 ; Ellen Moscoe 2 ; Natsayi Chimbindi 3 ; Kobus Herbst 3 ; Kevindra K. Naidu 3 ; FrankTanser 3 ; Deenan Pillay 3 ;Till Barnighausen 3

1 Boston University School of Public Health, Boston, MA, US; 2 Harvard School of Public Health, Boston, MA, US; 3 Wellcome Trust Africa Centre for Health and Population Studies, Somkhele, South Africa Background: Clinical trials are not well suited to evaluate the effectiveness and cost-effectiveness of interventions in “real world” settings. Using a quasi-experimental regression-discontinuity design (Bor et al. 2014), we establish the causal effect of early (vs. deferred) ART initiation on patient survival in rural South Africa, and obtain empirical (as opposed to modeled) cost-effectiveness estimates. Methods: Demographic data from a large population surveillance in rural KwaZulu-Natal were linked to clinical records from South Africa’s public sector ART program. 4391 patients enrolled in HIV care between 2007 and 2011. CD4 counts were collected upon entry into care regardless of ART initiation. Subjects were eligible for ART if CD4 < 200 cells/ μ L, as per national guidelines during this period. Dates of death were obtained from the demographic surveillance; dates of initiation and follow-up CD4 counts were obtained from clinical records. Patients were followed for up to five years. We estimated the causal effect of immediate ART eligibility on survival, immune health, and time spent in pre-ART and on ART, which were used to estimate costs. Effects were estimated using a regression-discontinuity design, which exploits the quasi-random nature of treatment assignment for patients with first CD4 counts close to the eligibility threshold. Patients just above vs. just below the threshold are similar on all observed and unobserved factors; but they receive different treatment assignments. Results: Patients presenting with a CD4+ count just below 200 cells/ μ L were 4.3% points (95% CI 0.6, 8.0) more likely to be alive at two years compared to patients presenting with a CD4+ count just above the cut-off, an advantage that persisted at five years (Fig 1). These effects imply a 14.9% point two-year survival advantage for patients who actually initiated ART because they had an eligible CD4+ count. Large, persistent gains in clinical immune function were also observed among patients who were ART eligible. Over a five- year horizon, the additional medical care provided to ART-eligible patients implied a cost of $1967 per life year saved compared to treating patients with CD4+ counts close to 200 cells/ μ L.

Oral Abstracts

Conclusions: In a real-world setting, referral of patients to pre-ART care (vs. immediate ART eligibility) led to large losses of life and health. These losses could have been avoided with immediate ART, which was found to be “very cost effective” at conventional benchmarks.

1111 Community-Based Strategies to Strengthen the Continuum of HIV Care Are Cost-Effective Jennifer A. Smith 1 ; Monisha Sharma 2 ; Carol Levin 2 ; Jared Baeten 2 ; Heidi van Rooyen 3 ; Connie Celum 2 ;Timothy Hallett 1 ; RuanneV. Barnabas 2 1 Imperial College London, London, United Kingdom; 2 University of Washington, Seattle, WA, US; 3 Human Sciences Research Council, Sweetwaters, South Africa

Background: Closing gaps in the continuum of HIV care is a priority for public health strategies that aim to reduce HIV-associated morbidity, mortality and HIV incidence. Facility-based HIV counselling and testing (HTC) has achieved limited testing coverage and linkage to care, particularly among asymptomatic persons. Home HTC and linkage to care achieved high testing coverage and linkage to care in KwaZulu-Natal, South Africa, but its impact on population-level health and cost-effectiveness compared to existing facility-based testing has not been evaluated. Methods: We developed an individual-based HIV transmission model parameterized with epidemiologic and cost data from home HTC and linkage studies in rural KwaZulu-Natal, South Africa. The HTC and linkage studies measured the change in the proportion of all HIV-positive persons with suppressed viral load between study enrolment and 12 months. The model simulated the intervention impact and projected the effect on health outcomes over 10 years. The incremental cost-effectiveness ratios (ICERs) were calculated for the intervention relative to existing facility-based testing per HIV incident infection and disability adjusted life year (DALY) averted. Results: With the high coverage (91%) and linkage to ART (80%) observed in the home HTC studies, HIV-associated disability and incident infections were reduced compared to current testing modalities, especially at higher ART initiation criteria: as the ART initiation threshold increased from ≤ 200 cells/mm 3 to universal eligibility, 10-22% of DALYs and 11-48% of HIV infections were averted over ten years. Home HTC is “very cost effective” by WHO standards across all ART initiation thresholds: US$1,080, $925, $985 and $1,150 per DALY averted and $7,000, $7,580, $7,100 and $6,560 per infection averted with ART initiation at ≤ 200 cells/mm 3 , ≤ 350 cells/mm 3 , ≤ 500 cells/mm 3 and universal eligibility, respectively. ART costs exceeded all other costs, accounting for 48-85% of total programme costs; with universal eligibility and a reduced ART cost, the ICER per DALY averted is reduced four-fold.

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CROI 2015