Impact and Cost-Effectiveness of Point-Of-Care CD4 Testing on the HIV Epidemic in South Africa.

Viviane D Lima,Alastair Heffernan,Anne Cori,Ranjeeta Thomas,Christophe Fraser,Michael Pickles,Ella Barber

doi:10.1371/journal.pone.0158303

Abstract

Rapid diagnostic tools have been shown to improve linkage of patients to care. In the context of infectious diseases, assessing the impact and cost-effectiveness of such tools at the population level, accounting for both direct and indirect effects, is key to informing adoption of these tools. Point-of-care (POC) CD4 testing has been shown to be highly effective in increasing the proportion of HIV positive patients who initiate ART. We assess the impact and cost-effectiveness of introducing POC CD4 testing at the population level in South Africa in a range of care contexts, using a dynamic compartmental model of HIV transmission, calibrated to the South African HIV epidemic. We performed a meta-analysis to quantify the differences between POC and laboratory CD4 testing on the proportion linking to care following CD4 testing. Cumulative infections averted and incremental cost-effectiveness ratios (ICERs) were estimated over one and three years. We estimated that POC CD4 testing introduced in the current South African care context can prevent 1.7% (95% CI: 0.4% - 4.3%) of new HIV infections over 1 year. In that context, POC CD4 testing was cost-effective 99.8% of the time after 1 year with a median estimated ICER of US$4,468/DALY averted. In healthcare contexts with expanded HIV testing and improved retention in care, POC CD4 testing only became cost-effective after 3 years. The results were similar when, in addition, ART was offered irrespective of CD4 count, and CD4 testing was used for clinical assessment. Our findings suggest that even if ART is expanded to all HIV positive individuals and HIV testing efforts are increased in the near future, POC CD4 testing is a cost-effective tool, even within a short time horizon. Our study also illustrates the importance of evaluating the potential impact of such diagnostic technologies at the population level, so that indirect benefits and costs can be incorporated into estimations of cost-effectiveness.

Highlights

Antiretroviral therapy (ART) substantially improves outcomes of human immunodeficiency virus (HIV) positive patients, if initiated early [1]
The results demonstrate that POC CD4 testing is more likely to be cost-effective when introduced into less comprehensive HIV care contexts: firstly, the probability of being cost-effective is higher in the current care context compared to the enhanced (ECT and Universal test and treat (UTT)) contexts, in which additional HIV testing occurs and retention in care is improved
This study shows that in the middle-income setting of South Africa, introduction of POC CD4 testing is likely to be cost-effective, in comparison to existing laboratory CD4 testing, and that cost-effectiveness increases over time

Summary

Introduction

Antiretroviral therapy (ART) substantially improves outcomes of human immunodeficiency virus (HIV) positive patients, if initiated early [1]. The remarkable expansion of ART availability across Sub-Saharan Africa, where 70% of worldwide infections occur [7], has led to a drop in AIDS-related deaths, which have decreased by 35% since peaking in 2005 [8]. In order to optimise the benefits of ART for the individual and the population, effective administration of the treatment cascade is essential. Improving the cascade implies early diagnosis, efficient linkage to care, timely ART initiation in those eligible for treatment, and regular follow-up to ensure adherence and sustained viral suppression. Attrition across the treatment cascade remains considerable, with only a quarter of HIV positive individuals in Sub-Saharan Africa estimated to be virally suppressed in 2012 [7]

Methods

Discussion

Conclusion