The cost-effectiveness of repeat HIV testing during pregnancy in a resource-limited setting.

OBJECTIVE: To estimate the cost-effectiveness of HIV screening strategies for the prevention of perinatal transmission in Uganda, a resource-limited country with high HIV prevalence and incidence. STUDY DESIGN: We designed a decision analytic model from a health care system perspective to assess the vertical transmission rates and cost-effectiveness of 4 different HIV screening strategies in pregnancy: (1) rapid HIV antibody (Ab) test at initial visit (current standard of care), (2) strategy 1 + HIV RNA at initial visit (adds detection of acute HIV), (3) strategy 1 + repeat HIV Ab at delivery (adds detection of incident HIV), and (4) strategy 3 + HIV RNA at delivery (adds detection of acute HIV at delivery). Model estimates were derived from the literature and local sources, and life years saved were discounted at a rate of 3% per year. Based on World Health Organization guidelines, we defined our cost-effectiveness threshold as ≤3 times the gross domestic product per capita, which for Uganda was US$3300 in 2008. RESULTS: Using base case estimates of 10% HIV prevalence among women entering prenatal care and 3% incidence during pregnancy, strategy 3 was incrementally the cost-effective option that led to the greatest total life years. CONCLUSIONS: Repeat rapid HIV Ab testing at the time of labor is a cost-effective strategy even in a resource-limited setting such as Uganda.

Cost-effectiveness of HIV screening of blood donations in Accra (Ghana).

OBJECTIVES: Areas with high HIV-incidence rates compared to the developed world may benefit from additional testing in blood banks and may show more favorable cost-effectiveness ratios. We evaluated the cost-effectiveness of adding p24 antigen, mini pool nucleic acid amplification testing (MP-NAT), or individual donation NAT (ID-NAT) to the HIV-antibody screening at the Korle Bu Teaching Hospital (Accra, Ghana), where currently only HIV-antibody screening is undertaken. METHODS: The residual risk of HIV transmission was derived from blood donations to the blood bank of the Korle Bu Teaching Hospital in 2004. Remaining life expectancies of patients receiving blood transfusion were estimated using the World Health Organization life expectancies. Cost-effectiveness ratios for adding the tests to HIV-antibody screening only were determined using a decision tree model and a Markov model for HIV. RESULTS: The prevalence of HIV was estimated at 1.51% in 18,714 donations during 2004. The incremental cost per disability-adjusted life-year (DALY) averted was US$1237 for p24 antigen, US$3142 for MP-NAT and US$7695 compared to the next least expensive strategy. HIV-antibody screening itself was cost-saving compared to no screening at all, gaining US$73.85 and averting 0.86 DALY per transfused patient. Up to a willingness-to-pay of US$2736 per DALY averted, HIV-antibody screening without additional testing was the most cost-effective strategy. Over a willingness-to-pay of US$11,828 per DALY averted, ID-NAT was significantly more cost-effective than the other strategies. CONCLUSIONS: Adding p24 antigen, MP-NAT, or ID-NAT to the current antibody screening cannot be regarded as a cost-effective health-care intervention for Ghana.

Benefits of HIV screening of blood transfusions in Zambia.

Blood transfusion continues to be an important route of transmission of HIV in developing countries, especially for young children following the perinatal period. Testing for HIV is costly and reliable donor support for the purchase of test kits is often essential, yet difficult to secure. The costs of screening transfusions for HIV and the financial benefits in terms of savings on treatment costs averted were calculated for a district hospital in Zambia where seroprevalence among donors was 15.9%. Financial benefits exceed costs by a factor of 2.7-3.5. In 1991, 1073 transfusions were given and an estimated 150 cases of transfusion-related AIDS were prevented by screening, of which 59% were in children aged 5 years or under and 31% were in women. The total cost of HIV screening was 3061 pounds ($4745), and the cost per case of HIV infection prevented was 20.40 pounds ($31.62); the cost of this protection for the population served by the hospital was 0.02 pounds ($0.03) per person. An estimated 3625 undiscounted healthy years of life were saved, of which nearly 69% were in children under 6, at a cost of 0.85 pounds ($1.32) per year of life saved. It is essential that financial and political support for HIV screening of blood for transfusion is maintained.

PIP: Monze Hospital is a 250-bed hospital located in the southern province of Zambia. In 1991 overall seroprevalence of HIV was about 15.9% among the hospital's blood donors. The usual procedure was to interview and weigh the donor, measure his or her hemoglobin concentration, and then to collect the blood. Blood was tested for HIV with HIVChek or another rapid test or by ELISA. The cost of testing was dependent on which HIV test was available at the time. A rapid test such as HIVChek was preferred but the price was high. The alternative was an ELISA such as the Wellcozyme ELISA. The total cost of collection of 1 unit of blood was about $11.76 when HIVChek was used, when ELISA was used, the cost of 1 unit was $9.69. For the 1073 units transfused in 1991, 1276 units had to be tested and 203 were rejected. About 2/3 of units were screened by HIVChek and 1/3 by ELISA. The approximate cost of blood collection was $14,128, of which HIV tests accounted for $4745, 33.6% of the total. About 16% of units were discarded because of HIV positivity, and the costs of this wastage brought the total cost per usable unit to an average of $12.82. A minimum of 11.4 of the 1073 units transfused were probably infected but were not detected by screening. Of these about 8 units would have caused new infections. Therefore, 150 infections were prevented by screening and the cost of HIV screening per infection prevented was $31.62. About 59% of infections prevented would have been in children no more than 5 years old and 31% in women. The cost of HIV screening was $4745, an annual expenditure of $0.03 per person. The cost of HIV screening per year of healthy life saved was $1.32. The cost to the health services of treating HIV disease in the 2 years before death was about $110.60 per person. The cost of screening blood in 1991 was estimated at $4745. Thus, the benefit/cost ratio was 3.5/1.