Improving ART programme retention and viral suppression are key to maximising impact of treatment as prevention - a modelling study

Scaling up a brief alcohol intervention to prevent HIV infection in Vietnam: a cluster randomized, implementation trial

BACKGROUND

Evidence-based interventions (EBIs) often address normative behaviors. If a behavior is also common among clinicians, they may be skeptical about the necessity or effectiveness of an EBI. Alternatively, clinicians' attitudes and behaviors may be misaligned, or they may lack the knowledge and self-efficacy to deliver the EBI. Several EBIs address unhealthy alcohol use, a common and often culturally acceptable behavior. But unhealthy alcohol use may be particularly harmful to people with HIV (PWH). Here, we present an implementation trial using an experiential implementation strategy to address clinicians' knowledge, attitudes, and behaviors. Clinicians receive the experiential intervention before they begin delivering an evidence-based brief alcohol intervention (BAI) to PWH with unhealthy alcohol use.

METHODS

Design: In this hybrid type 3 implementation-effectiveness cluster randomized controlled trial, ART clinics (n = 30) will be randomized 1:1 to facilitation, a flexible strategy to address implementation barriers, or facilitation plus the experiential brief alcohol intervention (EBAI). In the EBAI arm, clinicians, irrespective of their alcohol use, will be offered the BAI as experiential learning. EBAI will address clinicians' alcohol-related attitudes and behaviors and increase their knowledge and confidence to deliver the BAI.

PARTICIPANTS

ART clinic staff will be enrolled and assessed at pre-BAI training, post-BAI training, 3, 12, and 24 months. All PWH at the ART clinics who screen positive for unhealthy alcohol use will be offered the BAI. A subset of PWH (n = 810) will be enrolled and assessed at baseline, 3, and 12 months.

OUTCOMES

We will compare implementation outcomes (acceptability, fidelity, penetration, costs, and sustainability) and effectiveness outcomes (viral suppression and alcohol use) between the two arms. We will assess the impact of site-level characteristics on scaling-up the BAI. We will also evaluate how experiencing the BAI affected clinical staff's alcohol use and clinic-level alcohol expectations in the EBAI arm.

DISCUSSION

This trial contributes to implementation science by testing a novel strategy to implement a behavior change intervention in a setting in which clinicians themselves may engage in the behavior. Experiential learning may be useful to address normative and difficult to change lifestyle behaviors that contribute to chronic diseases.

TRIAL REGISTRATION

NCT06358885 (04/10/2024), https://clinicaltrials.gov/study/NCT06358885 .

Transmission reduction, health benefits, and upper-bound costs of interventions to improve retention on antiretroviral therapy: a combined analysis of three mathematical models

BACKGROUND

In this so-called treat-all era, antiretroviral therapy (ART) interruptions contribute to an increasing proportion of HIV infections and deaths. Many strategies to improve retention on ART cost more than standard of care. In this study, we aimed to estimate the upper-bound costs at which such interventions should be adopted.

METHODS

In this combined analysis, we compared the infections averted, disability-adjusted life-years (DALYs) averted, and upper-bound costs of interventions that improve ART retention in three HIV models with diverse structures, assumptions, and baseline settings: EMOD in South Africa, Optima in Malawi, and Synthesis in sub-Saharan African low-income and middle-income countries (LMICs). We modelled estimates over a 40-year time horizon, from a baseline of Jan 1, 2022, when interventions would be implemented, to Jan 1, 2062. We varied increment of ART retention (25%, 50%, 75%, and 100% retention), the extent to which interventions could be targeted towards individuals at risk of interrupting ART, and cost-effectiveness thresholds in each setting.

FINDINGS

Despite simulating different settings and epidemic trends, all three models produced consistent estimates of health benefit (ie, DALYs averted) and transmission reduction per increment in retention. The range of estimates was 1·35-3·55 DALYs and 0·12-0·20 infections averted over the 40-year time horizon per additional person-year retained on ART. Upper-bound costs varied by setting and intervention effectiveness. Improving retention by 25% among all people receiving ART, regardless of risk of ART interruption, gave an upper-bound cost per person-year of US$2-6 in Optima (Malawi), $43-68 in Synthesis (LMICs in sub-Saharan Africa), and $28-180 in EMOD (South Africa). A maximally targeted and effective retention intervention had an upper-bound cost per person-year of US$93-223 in Optima (Malawi), $871-1389 in Synthesis (LMICs in sub-Saharan Africa), and $1013-6518 in EMOD (South Africa).

INTERPRETATION

Upper-bound costs that could improve ART retention vary across sub-Saharan African settings and are likely to be similar to or higher than was estimated before the start of the treat-all era. Upper-bound costs could be increased by targeting interventions to those most at risk of interrupting ART.

FUNDING

Bill & Melinda Gates Foundation.

Baseline CD4 and mortality trends in the South African human immunodeficiency virus programme: Analysis of routine data

Background

Despite widespread availability of antiretroviral therapy (ART) in South Africa, there remains a considerable burden of human immunodeficiency virus (HIV)-related morbidity and mortality.

Objectives

To describe ART initiation and outcome trends over time, with a focus on clients presenting with advanced HIV-infection, so as to identify interventions to reduce morbidity and mortality.

Methods

Routine TIER.Net data from HIV-infected adults who had a documented baseline CD4 count and were newly initiating ART in Johannesburg or Mopani districts from 2004 to 2017 were analysed. Trends in baseline CD4 count and 5-year mortality were investigated and the population initiating ART with CD4 < 200 cells/mm³ was described.

Results

The Johannesburg and Mopani data sets comprised 203 131 and 101 814 records, respectively. Although median CD4 count increased over time, the proportion of initiations at CD4 < 200 cells/mm³ in 2017 remained high (Johannesburg 39%, Mopani 35%). Mortality was significantly increased among clients with CD4 < 200 compared to those with higher baseline counts (p < 0.001). Even though mortality among clients with low CD4 declined over time, likely because of improved drug regimens, in 2016-2017 mortality was still significantly increased among these clients (p < 0.001). Delivery of cotrimoxazole prophylaxis to clients with low CD4 declined over time to < 30% in 2017 and was associated with clinical stage. Presentation with CD4 < 200 cells/mm³ was associated with older age, male gender and hospitalisation.

Conclusion

A concerningly large proportion of South Africans still initiate ART at low CD4 counts. This is associated with increased mortality and requires targeted interventions to improve delivery of prophylactic regimens and early engagement in care.

Cost-effectiveness and budget impact of immediate antiretroviral therapy initiation for treatment of HIV infection in Côte d'Ivoire: A model-based analysis

Introduction

The Temprano and START trials provided evidence to support early ART initiation recommendations. We projected long-term clinical and economic outcomes of immediate ART initiation in Côte d’Ivoire.

Methods

We used a mathematical model to compare three potential ART initiation criteria: 1) CD4 <350/μL (ART<350/μL); 2) CD4 <500/μL (ART<500/μL); and 3) ART at presentation (Immediate ART). Outcomes from the model included life expectancy, 10-year medical resource use, incremental cost-effectiveness ratios (ICERs) in $/year of life saved (YLS), and 5-year budget impact. We simulated people with HIV (PWH) in care (mean CD4: 259/μL, SD 198/μL) and transmitted cases. Key input parameters to the analysis included first-line ART efficacy (80% suppression at 6 months) and ART cost ($90/person-year). We assessed cost-effectiveness relative to Côte d’Ivoire’s 2017 per capita annual gross domestic product ($1,600).

Results

Immediate ART increased life expectancy by 0.34 years compared to ART<350/μL and 0.17 years compared to ART<500/μL. Immediate ART resulted in 4,500 fewer 10-year transmissions per 170,000 PWH compared to ART<350/μL. In cost-effectiveness analysis, Immediate ART had a 10-year ICER of $680/YLS compared to ART<350/μL, ranging from cost-saving to an ICER of $1,440/YLS as transmission rates varied. ART<500/μL was “dominated” (an inefficient use of resources), compared with Immediate ART. Immediate ART increased the 5-year HIV care budget from $801.9M to $812.6M compared to ART<350/μL.

Conclusions

In Côte d’Ivoire, immediate compared to later ART initiation will increase life expectancy, decrease HIV transmission, and be cost-effective over the long-term, with modest budget impact. Immediate ART initiation is an appropriate, high-value standard of care in Côte d’Ivoire and similar settings.

Mathematical modelling to inform 'treat all' implementation in sub-Saharan Africa: a scoping review

OBJECTIVE

Despite widespread uptake, only half of sub-Saharan African countries have fully implemented the World Health Organization's 'treat all' policy, hindering achievement of global HIV targets. We examined literature on mathematical modelling studies that sought to inform scale-up and implementation of 'treat all' in sub-Saharan Africa.

METHODS

We conducted a scoping review, a research synthesis to assess emerging evidence and identify gaps, of peer-reviewed literature, extracting study characteristics on 'treat all' policies and assumptions, setting, key populations, outcomes and findings. Studies were narratively summarised and potential gaps characterised.

RESULTS

We identified 16 studies examining 'treat all' alone (n=12) or with expanded testing (n=7) and/or care continuum improvements (n=6). Twelve studies examined 'treat all' for Southern African countries, while none did so for Central Africa. Four included the role of resistance; one evaluated any key population. A range of health and economic outcomes were reported, although fewer studies formally assessed budget impact. Fourteen studies involved co-authors with any in-country affiliation; one study also had co-authors with local government affiliation. Overall, 'treat all' improves health outcomes and is cost-effective compared to deferred HIV treatment; 'treat all' with expanded testing or care continuum improvements may provide further health benefits. However, studies generally used optimistic assumptions about the implementation of expanded testing or care continuum improvements.

CONCLUSIONS

The modelling literature demonstrates improved health and economic benefits of 'treat all'. Using mathematical modelling to inform real-world implementation of 'treat all' requires realistic assumptions about expanded testing and care continuum interventions across a wide range of settings and populations.

Choice of time horizon critical in estimating costs and effects of changes to HIV programmes

BACKGROUND

Uganda changed its antiretroviral therapy guidelines in 2014, increasing the CD4 threshold for antiretroviral therapy initiation from 350 cells/μl to 500 cells/μl. We investigate what effect this change in policy is likely to have on HIV incidence, morbidity, and programme costs, and estimate the cost-effectiveness of the change over different time horizons.

METHODS

We used a complex individual-based model of HIV transmission and antiretroviral therapy scale-up in Uganda. 100 model fits were generated by fitting the model to 51 demographic, sexual behaviour, and epidemiological calibration targets, varying 96 input parameters, using history matching with model emulation. An additional 19 cost and disability weight parameters were varied during the analysis of the model results. For each model fit, the model was run to 2030, with and without the change in threshold to 500 cells/μl.

RESULTS

The change in threshold led to a 9.7% (90% plausible range: 4.3%-15.0%) reduction in incidence in 2030, and averted 278,944 (118,452-502,790) DALYs, at a total cost of $28M (-$142M to +$195M). The cost per disability adjusted life year (DALY) averted fell over time, from $3238 (-$125 to +$29,969) in 2014 to $100 (-$499 to +$785) in 2030. The change in threshold was cost-effective (cost <3×Uganda's per capita GDP per DALY averted) by 2018, and highly cost-effective (cost

CONCLUSIONS

Model results suggest that the change in threshold is unlikely to have been cost-effective to date, but is likely to be highly cost-effective in Uganda by 2030. The time horizon needs to be chosen carefully when projecting intervention effects. Large amounts of uncertainty in our results demonstrates the need to comprehensively incorporate uncertainties in model parameterisation.

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Key Words Collapse

MESH Headings

• Anti-HIV Agents/economics
• Anti-HIV Agents/therapeutic use
• CD4 Lymphocyte Count
• Cost-Benefit Analysis
• Female
• HIV Infections/drug therapy
• HIV Infections/economics
• HIV Infections/epidemiology
• Health Policy/economics
• Humans
• Incidence
• Male
• Models, Economic
• Quality-Adjusted Life Years
• Time Factors
• Uganda/epidemiology

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Grants

• G0601721 Medical Research Council
• MR/N014693/1 Medical Research Council
• PDF-2012-05-258 Department of Health
• MR/K012126/1 Medical Research Council
• MR/J005088/1 Medical Research Council

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Affiliation(s)

Nicky McCreesh London School of Hygiene and Tropical Medicine, London, United Kingdom
Ioannis Andrianakis London School of Hygiene and Tropical Medicine, London, United Kingdom
Rebecca N. Nsubuga MRC/UVRI Research Unit on AIDS, Entebbe, Uganda
Mark Strong Sheffield University, Sheffield, United Kingdom
Ian Vernon Durham University, Durham, United Kingdom
Trevelyan J. McKinley Exeter University, Exeter, United Kingdom
Jeremy E. Oakley Sheffield University, Sheffield, United Kingdom
Michael Goldstein Durham University, Durham, United Kingdom
Richard Hayes London School of Hygiene and Tropical Medicine, London, United Kingdom
Richard G. White London School of Hygiene and Tropical Medicine, London, United Kingdom

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