Is Increased Screening and Early Antiretroviral Treatment for HIV-1 Worth the Investment?

An Analysis of the Public Health and Economic Impact of Improvement in the UK

AJ Brogan; SE Talbird; AE Davis; L Wild; D Flanagan

Disclosures

HIV Medicine. 2019;20(10):668-680. 

In This Article

Discussion

The aim of this study was to assess the costs, health outcomes, and cost-effectiveness of increased HIV screening and early initiation of antiretroviral therapy among MSM, heterosexuals, and PWID in the UK. Using a Markov model to follow individuals with initially undiagnosed HIV-1 infection, our analysis found that increased screening in SHS coupled with early treatment initiation resulted in fewer onward HIV transmissions, more QALYs, and higher total costs. ICERs for heterosexuals (about £22 000 per QALY gained) were within typical UK willingness-to-pay thresholds and were well below these thresholds for MSM (about £9500 per QALY gained) and PWID (about £6500 per QALY gained). Sensitivity analysis showed that increased screening and early treatment initiation remained generally cost-effective in SHS and other care settings as long as positivity rates remained relatively high. While additional screening efforts may lead to lower positivity rates in the long term, relatively high rates seem likely while current suboptimal test coverage improves and individuals are offered and agree to testing based on risk.

Previous studies provide important context for our results. Among the most relevant are two UK modelling studies that assessed the cost-effectiveness of increasing screening in high-risk populations under older treatment initiation guidelines. One study found that increased screening was cost-effective (£17 500 per QALY gained) when treatment was initiated below 350 cells/μL.[11] Another study similarly reported that increased screening was cost-effective (£22 201 per QALY gained) when treatment was initiated according to 2010–2012 practices.[42] Our study extends the research in this area and shows that increased screening is likely to remain cost-effective even if all individuals follow current guidelines and begin treatment regardless of CD4 cell count within 3 months of diagnosis. Our study also reports projected outcomes separately for MSM, heterosexuals, and PWID, groups with widely different transmission risks, behavioural patterns, and positivity rates. Given limited resources to increase screening efforts, these subgroup-specific results may help decision makers understand where increased screening might have the most benefit.

This analysis has several limitations. First, the transmission model estimated only secondary infections and did not account for tertiary or further onward infections. Therefore, the model provides a conservative estimate of the benefits of increased screening and early treatment initiation on reduced onward transmission. Next, characteristics of initially undiagnosed individuals entering our model were based on surveillance data for individuals with new diagnoses in the UK because diagnosis is the first opportunity at which to collect data for this population. In sensitivity analysis, the scenario testing a healthier starting population had relatively limited impact on the model results. Finally, data for several of the model parameters were somewhat dated but were the most recent values available in the literature. These parameters included utility values, the CD4 cell count decline during salvage therapy, HIV-related mortality rates, and several parameters in the transmission model. Where trends in these parameters over time could be predicted, scenarios were included in the sensitivity analysis to examine the potential impact of newer data on the model results. The two most noteworthy of these scenarios showed that trends toward higher infectivity before treatment initiation and higher lifetime HIV management costs for secondary infections, which both seem likely given declining circumcision rates and lengthening life expectancies, yielded even more favourable results for increased screening and early treatment initiation.

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