EARLY INITIATION OF HAART TO FORESTALL AIDS-RELATED LYMPHOMA IN SOUTH AFRICA: A COST-EFFECTIVENESS ANALYSIS

Purpose: With the introduction of highly active antiretroviral therapy (HAART) in South Africa, a marked decline in AIDS-related illnesses and premature death has been observed; however, AIDS-related lymphoma incidence increased despite the large HAART roll-out programme. Earlier initiation of HAART therapy can reduce the risk of developing non-Hodgkin lymphoma but needs to be balanced with increased upfront cost, especially in a resource-limited setting. 

Method: We developed a linked transmission and health state transition (Markov) model to determine the cost-effectiveness of early HAART initiation from the public healthcare payer perspective. The CD4 count driven transmission model predicted lymphoma incidence in HIV-infected adults (aged 15 to 80 years) over a period of ten years. The Markov model predicted the health outcomes and costs. Data on transmission, transition probabilities, CD4 count thresholds, life expectancy, effectiveness and costs were obtained from the literature.

We compared early initiation of HAART at a CD4 cell count threshold of >500 cells/µL to initiation at <500 cells/µL, the current standard of care.

Our primary outcomes were Quality-adjusted life years (QALYs), expected costs, net monetary benefit and the incremental cost-effectiveness ratio (ICER). Health outcomes and costs are discounted at a rate of 5% per annum as recommended in South Africa.

We performed deterministic sensitivity analyses to assess parameter uncertainty.

Results: Early HAART initiation prevents lymphoma cases and related deaths, translating to 3.42 QALYs gained over the 10-year time horizon (6.44 vs. 3.02 expected QALYs with HAART initiation at >500 cells/µL and <500 cells/µL, respectively). The incremental cost of early initiation was $16,550 compared to the alternative. The NMB of early initiation was $90,165 and $38,303 for the alternative. HAART initiation at > 500cells/µL was therefore cost-effective with an ICER of $4,838/QALY gained.

Sensitivity analysis showed outcomes were sensitive to the effectiveness of HAART in preventing lymphoma, with early initiation being more sensitive than the base case.

Conclusion: Early HAART initiation at >500cells/µL would not only be effective in forestalling AIDS-related lymphoma but also cost-effective in resource limited settings.