COST-EFFECTIVENESS OF EXPANDED TESTING FOR HIV IN HIGHLY ENDEMIC REGIONS

Background: In response to the increasing availability of Highly Active Antiretroviral Therapy (HAART) in sub-Saharan Africa, the World Health Organization (WHO) recently recommended increased HIV testing to all adults and adolescents.  However, the costs, benefits, and cost-effectiveness of expanded testing are not known.

Methods: We used a dynamic simulation model to estimate the costs, quality of life, survival, and cost-effectiveness of expanded testing in South Africa compared with the current practice of voluntary counseling and testing (VCT).  In our base-case analysis, we simulated a cohort of 10,000 people (average age 32) with an initial prevalence rate of 19% over a 30-year time period.  Infected individuals were identified either when they developed an opportunistic infection or through testing.  Transmission was related to viral load, circumcision status, condom use, number of sexual partners, and HIV status of sexual partners.  Identified patients were eligible for HAART at a CD4 threshold of 200 cells/μl.

Results:  Given an expansion of annual testing capacity from 2% to 10% of the population, and testing once per lifetime, provider-initiated testing increased survival by 5.5 days, or 5.2 quality-adjusted days.  Over the 30-year period, there were 80 fewer HIV-related deaths in the expanded testing group.  The number of new infections was similar between the groups (incidence rate 1.7%/year), suggesting the reduced transmission from increased use of HAART and viral suppression was balanced by increased transmission from longer life expectancy and riskier sexual behavior in the expanded testing group compared to the VCT group.  The cost of expanded testing compared to VCT was higher by $23.6 per person, largely due to increased costs of HAART and patient monitoring (incremental cost-effectiveness ratio $1,567 per life-year gained).  Our results were sensitive to testing frequency, the probability that newly detected HIV+ individuals will have access to HAART, changes in quality of life with knowledge of HIV status, risk reduction from VCT, and the cost of VCT.

Conclusions: Expanded testing is an effective intervention for reducing the number of deaths and prolonging quality-adjusted life expectancy in resource-limited regions.  The cost-effectiveness of expanded screening is similar to other interventions recommended by the World Health Organization.