Effectiveness of and Financial Returns to Voluntary Medical Male Circumcision for HIV Prevention in South Africa: An Incremental Cost-Effectiveness Analysis

Background: Empirical studies and population-level policy simulations show the importance of voluntary medical male circumcision (VMMC) in generalized epidemics. This paper complements available scenario-based studies (projecting costs and outcomes over some policy period, typically spanning decades) by adopting an incremental approach—analyzing the expected consequences of circumcising one male individual with specific characteristics in a specific year. This approach yields more precise estimates of VMMC’s cost-effectiveness and identifies the outcomes of current investments in VMMC (e.g., within a fiscal budget period) rather than of investments spread over the entire policy period. Methods/Findings: The model has three components. We adapted the ASSA2008 model, a demographic and epidemiological model of the HIV epidemic in South Africa, to analyze the impact of one VMMC on HIV incidence over time and across the population. A costing module tracked the costs of VMMC and the resulting financial savings owing to reduced HIV incidence over time. Then, we used several financial indicators to assess the cost-effectiveness of and financial return on investments in VMMC. One circumcision of a young man up to age 20 prevents on average over 0.2 HIV infections, but this effect declines steeply with age, e.g., to 0.08 by age 30. Net financial savings from one VMMC at age 20 are estimated at US$617 at a discount rate of 5% and are lower for circumcisions both at younger ages (because the savings occur later and are discounted more) and at older ages (because male circumcision becomes less effective). Investments in male circumcision carry a financial rate of return of up to 14.5% (for circumcisions at age 20). The cost of a male circumcision is refinanced fastest, after 13 y, for circumcisions at ages 20 to 25. Principal limitations of the analysis arise from the long time (decades) over which the effects of VMMC unfold—the results are therefore sensitive to the discount rate applied, and more generally to the future course of the epidemic and of HIV/AIDS-related policies pursued by the government. Conclusions: VMMC in South Africa is highly effective in reducing both HIV incidence and the financial costs of the HIV response. The return on investment is highest if males are circumcised between ages 20 and 25, but this return on investment declines steeply with age. Medical male circumcision reduces incidences of HIV. Gorgens and colleagues present a new model that identifies the best age for this treatment, in terms of cost efficiencies and disease incidence.Background: Every year, about 2 million people become infected with HIV, the virus that causes AIDS. Although antiretroviral therapy can keep HIV in check, there is no cure for AIDS. Consequently, prevention of HIV transmission is an important component of efforts to control the AIDS epidemic. Because HIV is most often spread through unprotected sex with an infected partner, individuals can reduce their risk of becoming infected by abstaining from sex, by having only one or a few sexual partners, and by using male or female condoms. In addition, three trials undertaken in sub-Saharan Africa a decade ago showed that male circumcision—the surgical removal of the foreskin, a loose fold of skin that covers the head of the penis—can halve the sexual transmission of HIV from HIV-positive women to HIV-negative men. In 2007, the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) recommended that individuals living in countries with generalized HIV epidemics (countries where more than 1% of the general population is HIV positive) should be offered voluntary medical male circumcision (VMMC) to help prevent HIV transmission. Why Was This Study Done?: In 2011, following several studies that assessed the population-level effectiveness and cost-effectiveness of VMMC scale-up, WHO/UNAIDS set a target of having at least 80% of all men aged 15–49 circumcised in 14 priority countries in Africa by 2015. Good progress towards this target was made, but VMMC scale-up needs further improvement. Scenario-based studies provide estimates of the overall costs and impacts of VMMC policies over the whole policy period, which can span several decades, but policy makers sometimes need to know the returns on investments in VMMC over the current financial year. Here, the researchers use an “incremental” cost-effectiveness approach (one that analyzes the expected consequences of circumcising one male with specific characteristics in a specific year) to provide estimates of the impacts of current VMMC investments and to obtain more precise estimates of VMMC’s cost-effectiveness for HIV prevention in South Africa, a country with a generalized HIV epidemic. What Did the Researchers Do and Find?: The researchers developed a mathematical model consisting of three elements: a demographic and epidemiological model of the South African HIV epidemic adapted to analyze the impact of one VMMC on HIV incidence over time and across the population; a module to track the costs of VMMC and financial savings from HIV infections averted by VMMC; and several financial indicators to assess the cost-effectiveness of and financial return on investments in VMMC. Using this model, the researchers estimate that the circumcision of a young man up to age 20 prevents, on average, 0.2 HIV infections, and that the number of infections averted by VMMC declines steeply with age at circumcision. Estimated financial savings from one VMMC at age 20 are US$617 at a discount rate of 5% (discounting translates future costs and benefits into present-day values); VMMC at younger and older ages results in lower financial savings. From a purely financial perspective, circumcisions at age 20 are most effective with a financial return of 14.5% (they are equivalent to a financial investment yielding an interest of 14.5% annually). Finally, the costs of a circumcision are refinanced (covered by reductions in the costs associated with HIV infection) fastest for circumcisions at ages 20–25. What Do These Findings Mean?: Because the effects of VMMC unfold over many decades, the accuracy of these findings is likely to be affected by the future course of the AIDS epidemic, by HIV/AIDS policies adopted by the South African government, and by the discount rate applied in the cost-effectiveness analysis. Moreover, some of the assumptions made by the researchers in their model may affect the accuracy of their findings. Overall, however, these findings, which provide estimates of the consequences of current VMMC policies, suggest that VMMC in South Africa (and possibly in settings where a lower proportion of the population is HIV positive) is a highly effective HIV prevention intervention that is cost-saving under many circumstances. These findings also indicate how age at circumcision affects the impacts of circumcision. Specifically, they suggest that the return on investment is highest if males are circumcised between ages 20 and 25 but declines steeply with increasing age. Additional Information: This list of resources contains links that can be accessed when viewing the PDF on a device or via the online version of the article at http://dx.doi.org/10.1371/journal.pmed.1002012.