Supporting Sustained HIV Treatment Adherence After Initiation

The study's primary research goal is to identify the optimal combination of evidence-based and scalable HIV interventions for low-resource, high-burden settings. The investigators propose to 1) test the relative contribution of five promising intervention components; 2) collect cost and other implementation data; and 3) create a multi-component intervention package to optimize cost-effectiveness and implementation success. Of the five components, three are methods of non-adherence detection plus patient outreach; two are adherence support methods that can be integrated into Cape Town healthcare systems. These will not overcome all challenges that ART patients experience (e.g., structural barriers such as food insecurity) but they represent scalable, feasible, acceptable, and effective options. Notably, they are all behavioral approaches grounded in the experience and priorities of local health officials with whom the investigators have worked to identify scaleable interventions. While the study will be in Cape Town, it is broadly adaptable to other resource-limited settings.

The gold standard for testing interventions is the randomized controlled trial (RCT), which minimizes bias when testing cause and effect of a new exposure. When testing an intervention with more than one element, however, untangling the effect of individual elements is impossible. Indeed, data on the performance of individual components and their interactions-critical for developing and refining the components of a packaged intervention-is lost in an RCT. Notably, clinical care typically relies on packages of services, not single interventions, and packaged interventions are recommended for ART support. An effective way to test a multi-component intervention is to use the novel Multiphase Optimization STrategy (MOST), an engineering-inspired method for identifying the most efficacious combination of components in a packaged intervention, thus allowing researchers to drop inactive or weakly-performing components and construct an optimized package based on effect, cost, and other features. Once the optimized multi-component intervention is chosen, an RCT or quasi-experiment can follow to determine whether the optimized package yields superior outcomes compared to existing standards. MOST encompasses three phases: 1) preparation; 2) optimization; and 3) evaluation, often in an RCT. In this project, we have completed preparation, including a pilot study in Cape Town. SUSTAIN will comprise the middle optimization phase. The evaluation phase will be the focus of a future study.

The specific aims are:

Aim 1. Employ a highly efficient fractional factorial design to determine the effects of five intervention components on the primary outcome (HIV viral suppression) and secondary outcomes (ART adherence measured by EAM, ART retention per clinic records, days of unsuppressed virus, time to nonadherence detection, and time to linkage to support). The investigators will explore effect mechanisms quantitatively and qualitatively.

Aim 2. Evaluate the intervention components to address implementation, service, and client outcomes according to the Proctor framework. Data collection will involve tracking of intervention component use, time and motion studies, and quantitative surveys and qualitative interviews with participants and staff.

Aim 3. Use the effectiveness data collected in Aim 1 and the implementation and client outcomes in Aim 2 to model the multi-component intervention optimized for cost-effectiveness and implementation success.

Study Summary This study is designed to advance the translation of evidence-based interventions into clinical settings to benefit patients. There is ample evidence on what works to support ART adherence and retention-much of it from our own research. The investigators partnered with local officials and clinical staff in Cape Town to review the evidence and to conduct formative research to identify the most effective, acceptable, and feasible intervention options for patients and providers. The proposed study represents the next critical step: the investigators will test the intervention components that emerged from the formative work, encompassing elements to both rapidly identify nonadherent patients and to strengthen the support they receive once identified, to provide the data needed to construct the most cost-effective and sustainable multi-component intervention. The choice of intervention components will allow a critical test of advanced monitoring technology compared to simpler tools to identify nonadherence. By using an innovative MOST design to guide collection and analysis of efficacy, cost, and other implementation data, the study aligns with NIH's goals of using novel scientific methods to advance implementation science.