Using a Modeling-Based Approach to Assess and Optimize HIV Linkage to Care Services

Understanding effective post-test linkage strategies for HIV prevention and care: a scoping review

INTRODUCTION

Following HIV testing services (HTS), the World Health Organization recommends prompt linkage to prevention and treatment. Scale-up of effective linkage strategies is essential to achieving the global 95-95-95 goals for maintaining low HIV incidence by 2030 and reducing HIV-related morbidity and mortality. Whereas linkage to care including same-day antiretroviral therapy (ART) initiation for all people with HIV is now routinely implemented in testing programmes, linkage to HIV prevention interventions including behavioural or biomedical strategies, for HIV-negative individuals remains sub-optimal. This review aims to evaluate effective post-HTS linkage strategies for HIV overall, and highlight gaps specifically in linkage to prevention.

METHODS

Using the five-step Arksey and O'Malley framework, we conducted a scoping review searching existing published and grey literature. We searched PubMed, Cochrane Library, CINAHL, Web of Science and EMBASE databases for English-language studies published between 1 January 2010 and 30 November 2023. Linkage interventions included as streamlined interventions-involving same-day HIV testing, ART initiation and point-of-care CD4 cell count/viral load, case management-involving linkage coordinators developing personalized HIV care and risk reduction plans, incentives-financial and non-financial, partner services-including contact tracing, virtual-like social media, quality improvement-like use of score cards, and peer-based interventions. Outcomes of interest were linkage to any form of HIV prevention and/or care including ART initiation.

RESULTS

Of 2358 articles screened, 66 research studies met the inclusion criteria. Only nine linkage to prevention studies were identified (n = 9/66, 14%)-involving pre-exposure prophylaxis, voluntary medical male circumcision, sexually transmitted infection and cervical cancer screening. Linkage to care studies (n = 57/66, 86%) focused on streamlined interventions in the general population and on case management among key populations.

DISCUSSION

Despite a wide range of HIV prevention interventions available, there was a dearth of literature on HIV prevention programmes and on the use of messaging on treatment as prevention strategy. Linkage to care studies were comparatively numerous except those evaluating virtual interventions, incentives and quality improvement.

CONCLUSIONS

The findings give insights into linkage strategies but more understanding of how to provide these effectively for maximum prevention impact is needed.

The Application of Systems Thinking to the Prevention and Control of Sexually Transmissible Infections among Adolescents and Adults: A Scoping Review

Systems thinking is a mechanism for making sense of complex systems that challenge linear explanations of cause-and-effect. While the prevention and control of sexually transmissible infections (STIs) has been identified as an area that may benefit from systems-level analyses, no review on the subject currently exists. The aim of this study is to conduct a scoping review to identify literature in which systems thinking has been applied to the prevention and control of STIs among adolescent and adult populations. Joanna Briggs Institute guidelines for the conduct of scoping reviews were followed. Five databases were searched for English-language studies published after 2011. A total of n = 6102 studies were screened against inclusion criteria and n = 70 were included in the review. The majority of studies (n = 34) were conducted in African nations. Few studies focused on priority sub-populations, and 93% were focused on HIV (n = 65). The most commonly applied systems thinking method was system dynamics modelling (n = 28). The review highlights areas for future research, including the need for more STI systems thinking studies focused on: (1) migrant and Indigenous populations; (2) conditions such as syphilis; and (3) innovations such as pre-exposure prophylaxis and at-home testing for HIV. The need for conceptual clarity around 'systems thinking' is also highlighted.

Leveraging Complex Systems Science to Advance Sexual and Gender Minority Youth Health Research and Equity

Over the past two decades, sexual and gender minority (SGM) youth health inequities have remained the same or widened, highlighting the need for new approaches to foster health equity. Complex systems science (CSS) techniques must be added to our armamentarium because of the following: CSS techniques can model cyclical feedback loops inherent in the relationships between SGM youth health outcomes and their multilevel causes, thereby enhancing the integration of real-world complexity in scientific models; and CSS can simulate multiple hypothetical interventions, thereby identifying future interventions with great potential impact. We describe four promising CSS techniques for advancing SGM youth health equity.