HIV This Week

Bendavid E, Young SD, Katzenstein DA, Bayoumi AM, Sanders GD, Owens DK. Cost-effectiveness of HIV monitoring strategies in resource-limited settings: a southern African analysis. Arch Intern Med 2008; 22;168(17):1910-8.

Although the number of infected persons receiving highly active antiretroviral therapy in low- and middle-income countries has increased dramatically, optimal disease management is not well defined. Bendavid and colleagues developed a model to compare the costs and benefits of 3 types of human immunodeficiency virus monitoring strategies: symptom-based strategies, CD4-based strategies, and CD4 counts plus viral load strategies for starting, switching, and stopping antiretroviral therapy. They used clinical and cost data from southern Africa and performed a cost-effectiveness analysis. All assumptions were tested in sensitivity analyses. Compared with the symptom-based approaches, monitoring CD4 counts every 6 months and starting treatment at a threshold of 200/muL was associated with a gain in life expectancy of 6.5 months (61.9 months vs. 68.4 months) and a discounted lifetime cost savings of US $464 per person (US $4069 vs. US $3605, discounted 2007 dollars). The CD4-based strategies in which treatment was started at the higher threshold of 350/microL provided an additional gain in life expectancy of 5.3 months at a cost-effectiveness of US $107 per life-year gained compared with a threshold of 200/microL. Monitoring viral load with CD4 was more expensive than monitoring CD4 counts alone, added 2.0 months of life, and had an incremental cost-effectiveness ratio of US $5414 per life-year gained relative to monitoring of CD4 counts. In sensitivity analyses, the cost savings from CD4 count monitoring compared with the symptom-based approaches was sensitive to cost of inpatient care, and the cost-effectiveness of viral load monitoring was influenced by the per test costs and rates of virologic failure. Use of CD4 monitoring and early initiation of antiretroviral therapy in southern Africa provides large health benefits relative to symptom-based approaches for antiretroviral therapy management. In southern African countries with relatively high costs of hospitalization, CD4 monitoring would likely reduce total health care expenditures. The cost-effectiveness of viral load monitoring depends on test prices and rates of virologic failure.

Editors’ note: Using the often cited ‘twice the per capita gross domestic product’ as an acceptable cost-effectiveness ratio for developing countries, monitoring CD4 counts is cost-effective in all parts of southern Africa. Using CD4 count monitoring to initiate antiretroviral treatment at 350 cells/µl, before onset of serious opportunistic diseases and severe immune compromise, can be facilitated by recent advances in CD4 enumeration technology with lower per test costs. Smaller machines have been now designed that require less infrastructure, maintenance, and technical expertise.