Systems mapping methods are increasingly used to study complex public health issues. Visualizing the causal relationships within a complex adaptive system allows for more than developing a holistic and multi-perspective overview of the situation. It is also a way of understanding the emergent, self-organizing dynamics of a system and how they can be influenced. This article describes a concrete approach for developing and analysing a systems map of a complex public health issue drawing on well-accepted methods from the field of social science while incorporating the principles of systems thinking and transdisciplinarity. Using our case study on HIV drug resistance in sub-Saharan Africa as an example, this article provides a practical guideline on how to map a public health problem as a complex adaptive system in order to uncover the drivers, feedback-loops and other dynamics behind the problem. Qualitative systems mapping can help researchers and policy makers to gain deeper insights in the root causes of the problem and identify complexity-informed intervention points.

Background: HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR are driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remains unclear and African policy makers encounter difficulties setting priorities combating HIVDR. By viewing HIVDR as a complex adaptive system, through the eyes of multi-disciplinary HIVDR experts, we aimed to make a first attempt to linking different influencing factors and gaining a deeper understanding of the complexity of the system. Methods: We designed a detailed systems map of factors influencing HIVDR based on semi-structured interviews with 15 international HIVDR experts from or with experience in sub-Saharan Africa, from different disciplinary backgrounds and affiliated with different types of institutions. The resulting detailed system map was conceptualized into three main HIVDR feedback loops and further strengthened with literature evidence. Results: Factors influencing HIVDR in sub-Saharan Africa and their interactions were sorted in five categories: biology, individual, social context, healthcare system and ‘overarching’. We identified three causal loops cross-cutting these layers, which relate to three interconnected subsystems of mechanisms influencing HIVDR. The ‘adherence motivation’ subsystem concerns the interplay of factors influencing people living with HIV to alternate between adherence and non-adherence. The ‘healthcare burden’ subsystem is a reinforcing loop leading to an increase in HIVDR at local population level. The ‘ART overreliance’ subsystem is a balancing feedback loop leading to complacency among program managers when there is overreliance on ART with a perceived low risk to drug resistance. The three subsystems are interconnected at different levels. Conclusions: Interconnectedness of the three subsystems underlines the need to act on the entire system of factors surrounding HIVDR in sub-Saharan Africa in order to target interventions and to prevent unwanted effects on other parts of the system. The three theories that emerged while studying HIVDR as a complex adaptive system form a starting point for further qualitative and quantitative investigation.

HIV drug resistance (HIVDR) is a complex problem with multiple interconnected and context dependent causes. Although the factors influencing HIVDR are known and well-studied, HIVDR remains a threat to the effectiveness of antiretroviral therapy. To understand the complexity of HIVDR, a comprehensive, systems approach is needed. Therefore, a local systems map was developed integrating all reported factors influencing HIVDR in the Dar es Salaam Urban Cohort Study area in Tanzania. The map was designed based on semi-structured interviews and workshops with people living with HIV and local actors who encounter people living with HIV during their daily activities. We visualized the feedback loops driving HIVDR, compared the local map with a systems map for Sub-Saharan Africa, previously constructed from interviews with international HIVDR experts, and suggest potential interventions to prevent HIVDR. We found several interconnected balancing and reinforcing feedback loops related to poverty, stigmatization, status disclosure, self-esteem, knowledge about HIVDR and healthcare system workload, among others, and identified three potential leverage points. Insights from this local systems map were complementary to the insights from the Sub-Saharan systems map showing that both viewpoints are needed to fully understand the system. This study provides a strong baseline for quantitative modelling, and for the identification of context-dependent, complexity-informed leverage points.

IntroductionHIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR is driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remain unclear and African policy makers encounter difficulties setting priorities combating HIVDR. By employing a systems approach, involving multi-disciplinary HIVDR experts, we aimed to gain a deeper understanding of key determinants and their interactions driving HIVDR. MethodsWe designed a detailed system map of factors influencing HIVDR based on semi-structured interviews with 15 international HIVDR experts from or with experience in Sub-Saharan Africa. from different disciplinary backgrounds and institutions. The resulting detailed system map was conceptualized into three main HIVDR feedback loops and further strengthened with literature evidence.ResultsFactors influencing HIVDR in SSA and their interactions were sorted in five categories: biology, individual, social context, healthcare system and ‘overarching’. We identified three causal loops cross-cutting these layers, which relate to three interconnected subsystems of mechanisms influencing HIVDR. The ‘adherence motivation’ subsystem consists of opposite forces that ultimately create a balancing loop leading to a different set-point of adherence per individual which may vary over time. The ‘healthcare burden’ subsystem consists of a reinforcing loop leading to an increased HIVDR at local population level. The ‘ART overreliance’ subsystem is a balancing feedback loop leading to complacency among program managers when there is overreliance on ART with a perceived low risk to drug resistance. The three subsystems are interconnected at different levels. ConclusionsInterconnectedness of the three subsystems underlines the need to act on the entire system of factors surrounding HIVDR in Sub-Saharan Africa in order to target interventions and to prevent unwanted effects on other parts of the system.

In sub-Saharan Africa, the burden on HIV care givers is high. This resulted in renewed interest in community health worker (CHW) programs. We conducted a review of the literature to summarize CHWs' effects on HIV therapy outcome. We also investigated which CHW tasks might favorably impact treatment outcome. We conducted a comprehensive literature search in PubMed, Web of Science and Embase for papers published up to October 2018. The studies included were conducted on HIV-positive adults in sub-Saharan Africa and reported biological HIV outcomes. We systematically collected data on HIV therapy outcome and CHW tasks. We used Bayesian network modelling for the analysis of CHW tasks. We included 19 studies in total: 4 randomized controlled trials, 8 comparative cohort studies and 7 single arm interventions. In all studies, CHW interventions were beneficial or not inferior to standard of care (SOC). The more common tasks of CHWs involved an important human support component, with home visits being the most common task. Upon analysis we found indications that ART delivery, individual adherence support and frequent home visits were predictive of a successful CHW intervention, defined as improved therapy outcome compared to SOC or reaching 90% of treated patients being virally suppressed. We found that CHW interventions are not inferior to SOC and might even be beneficial. We hypothesize that ART delivery, individual adherence support and frequent home visits are predictive of a successful CHW intervention. Further research is needed to be able to judge whether any single task or a particular combination of tasks is significantly correlated with a successful CHW intervention, or whether such tasks are context specific.