The clinical impact and cost-effectiveness of routine, voluntary HIV screening in South Africa.

BACKGROUND: Although 900,000 HIV-infected South Africans receive antiretroviral therapy, the majority of South Africans with HIV remain undiagnosed.
METHODS: We use a published simulation model of HIV case detection and treatment to examine 3 HIV screening scenarios, in addition to current practice as follows: (1) one-time; (2) every 5 years; and (3) annually. South African model input data include the following: 16.9% HIV prevalence, 1.3% annual incidence, 49% test acceptance rate, HIV testing costs of $6.49/patient, and a 47% linkage-to-care rate (including 2 sequential antiretroviral therapy regimens) for identified cases. Outcomes include life expectancy, direct medical costs, and incremental cost-effectiveness.
RESULTS: HIV screening one-time, every 5 years, and annually increase HIV-infected quality-adjusted life expectancy (mean age 33 years) from 180.6 months (current practice) to 184.9, 187.6, and 197.2 months. The incremental cost-effectiveness of one-time screening is dominated by screening every 5 years. Screening every 5 years and annually each have incremental cost-effectiveness ratios of $1570/quality-adjusted life year and $1720/quality-adjusted life year. Screening annually is very cost-effective even in settings with the lowest incidence/prevalence, with test acceptance and linkage rates both as low as 20%, or when accounting for a stigma impact at least four-fold that of the base case.
CONCLUSIONS: In South Africa, annual voluntary HIV screening offers substantial clinical benefit and is very cost-effective, even with highly constrained access to care and treatment.