Expanding antiretroviral options in resource-limited settings--a cost-effectiveness analysis.
BACKGROUND
Current World Health Organization (WHO) guidelines for treatment of HIV in resource-limited settings call for 2 antiretroviral regimens. The effectiveness and cost-effectiveness of increasing the number of antiretroviral regimens is unknown.


METHODS
Using a simulation model, we compared the survival and costs of current WHO regimens with two 3-regimen strategies: an initial regimen of 3 nucleoside reverse transcriptase inhibitors followed by the WHO regimens and the WHO regimens followed by a regimen with a second-generation boosted protease inhibitor (2bPI). We evaluated monitoring with CD4 counts only and with both CD4 counts and viral load. We used cost and effectiveness data from Cape Town and tested all assumptions in sensitivity analyses.


RESULTS
Over the lifetime of the cohort, 25.6% of individuals failed both WHO regimens by virologic criteria. However, when patients were monitored using CD4 counts alone, only 6.5% were prescribed additional highly active antiretroviral therapy due to missed and delayed detection of failure. The life expectancy gain for individuals who took a 2bPI was 6.7-8.9 months, depending on the monitoring strategy. When CD4 alone was available, adding a regimen with a 2bPI was associated with an incremental cost-effectiveness ratio of $2581 per year of life gained, and when viral load was available, the ratio was $6519 per year of life gained. Strategies with triple-nucleoside reverse transcriptase inhibitor regimens in initial therapy were dominated. Results were sensitive to the price of 2bPIs.


CONCLUSIONS
About 1 in 4 individuals who start highly active antiretroviral therapy in sub-Saharan Africa will fail currently recommended regimens. At current prices, adding a regimen with a 2bPI is cost effective for South Africa and other middle-income countries by WHO standards.
Bendavid
Eran
E
Department of Medicine, Center for Health Policy and Center for Primary Care and Outcomes Research, Stanford University, Stanford, CA 94305, USA. ebd@stanford.edu
Wood
Robin
R
Katzenstein
David A
DA
Bayoumi
Ahmed M
AM
Owens
Douglas K
DK
D017954:Africa South of the Sahara; D019380:Anti-HIV Agents / Q000191:economics / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active / Q000191:economics* / Q000706:statistics & numerical data; D018791:CD4 Lymphocyte Count; D003362:Cost-Benefit Analysis / Q000191:economics / Q000706:statistics & numerical data; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics* / Q000401:mortality; D017320:HIV Protease Inhibitors / Q000191:economics / Q000627:therapeutic use; D017048:Health Care Costs / Q000706:statistics & numerical data; D006295:Health Resources / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D055656:Prescriptions / Q000191:economics; D018894:Reverse Transcriptase Inhibitors / Q000191:economics / Q000627:therapeutic use; D017211:Treatment Failure; D019562:Viral Load
D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D018894:Reverse Transcriptase Inhibitors