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

Abstract and Introduction

Abstract

Objectives: Early treatment of HIV-1 infection at all CD4 levels has demonstrated clinical and public health benefits. This analysis examined the costs, health outcomes, and cost-effectiveness of increased HIV-1 screening and early treatment initiation in the UK.

Methods: A Markov model followed theoretical cohorts of men who have sex with men (MSM), heterosexuals, and people who inject drugs (PWID) with initially undiagnosed HIV-1 infection over their remaining lifetimes. The analysis examined increased HIV-1 screening (resulting in 10–50% improvements in diagnosis rates) versus current screening in sexual health services (SHS) and other settings, with all individuals initiating treatment within 3 months of diagnosis. Health status was modelled by viral load and CD4 cell count as individuals progressed to diagnosis and treatment. Individuals accrued quality-adjusted life-years (QALYs), incurred costs for screening and HIV-related clinical management, and were at risk of transmitting HIV-1 infection to their partners. Input parameter data were taken primarily from UK-specific published sources. All outcomes were discounted at 3.5% annually.

Results: The model estimated that increased screening and early treatment resulted in fewer onward HIV transmissions, more QALYs, and higher total costs. For SHS, incremental cost-effectiveness ratios (ICERs) for heterosexuals (~£22 000/QALY gained) were within typical UK willingness-to-pay thresholds and were well below these thresholds for MSM (~£9500/QALY gained) and PWID (~£6500/QALY gained). Sensitivity analysis showed that model results were robust.

Conclusions: Increased HIV-1 screening and early treatment initiation may be a cost-effective strategy to reduce HIV transmission and improve health for MSM, heterosexuals, and PWID in the UK.

Introduction

Over the past decade, there has been a trend towards earlier treatment of HIV-1 infection because of the demonstrated clinical benefits and because the availability of various well-tolerated, effective, and durable antiretroviral treatments has diminished concern about long-term toxicity and exhausting treatment options. The Strategic Timing of Antiretroviral Treatment (START) clinical trial was a large, international study [including participants from the USA, the UK, and other member countries of the European Union (EU)] examining the impact of early versus later treatment for treatment-naïve adults.[1] START found significantly fewer AIDS- and non-AIDS-defining events among individuals who received early treatment (CD4 cell count > 500 cells/μL) than among individuals who initiated treatment after their CD4 cell counts dropped below 350 cells/μL. This and other clinical evidence led to updates of HIV treatment guidelines in the UK, EU (late 2015), and USA (early 2016) recommending treatment regardless of CD4 cell count.[2–4]

Earlier treatment has also been found to be beneficial in preventing onward transmissions, as individuals with undetectable viral load do not transmit HIV to their partners. The Partners of People on ART—A New Evaluation of the Risks (PARTNER) study enrolled 1166 serodifferent couples, including both heterosexual couples and men who have sex with men (MSM), in 14 European countries. Among the 888 couples who contributed to follow-up with suppressive therapy (HIV-1 RNA < 200 copies/mL) and 58 000 condomless sex acts, the study found no phylogenetically linked transmissions.[5] Various other studies, including the recent PARTNER2 extension among MSM and an earlier study primarily among heterosexual couples, have shown similar results.[6,7]

Based on the clinical benefits of early treatment and the additional public health benefit of avoided onward transmissions, it is important for individuals to be diagnosed and receive treatment as early as possible. National screening recommendations encourage testing in a variety of settings, such as sexual health services (SHS, where most new HIV diagnoses occur), general practice, secondary care, and community, self-sampling, and home testing, particularly in geographies and population groups at increased risk. Despite these recommendations, tests offered and accepted both remain suboptimal[8] and a high proportion of individuals are still diagnosed late, with about 40% diagnosed with CD4 cell counts < 350 cells/μL and 21% diagnosed with counts < 200 cells/μL.[9,10] Additional screening coupled with early treatment could help further reduce HIV-related morbidity, mortality, and transmission in the UK.

Increased screening, however, is likely to impose additional costs both for testing and for treatment. A previous UK-based study found increased screening to be generally cost-effective when treatment was initiated at CD4 cell counts < 350 cells/μL.[11] However, it is important to understand the costs and the cost-effectiveness of increased screening in the light of the recommendations regarding early treatment initiation regardless of CD4 cell count. Further, given limited resources to increase screening efforts, it is important to consider specific population subgroups and care settings to understand where increased screening efforts might have the most benefit.

The aim of this study was to assess the costs, health outcomes, and cost-effectiveness of increased screening and early treatment initiation in various care settings for three specific population subgroups, MSM, heterosexuals, and people who inject drugs (PWID), in the UK.

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