Systems Science for Caribbean Health: the development and piloting of a model for guiding policy on diabetes in the Caribbean

Understanding the complexity of individual developmental pathways: A primer on metaphors, models, and methods to study resilience in development

The modern study of resilience in development is conceptually based on a complex adaptive system ontology in which many (intersystem) factors are involved in the emergence of resilient developmental pathways. However, the methods and models developed to study complex dynamical systems have not been widely adopted, and it has recently been noted this may constitute a problem moving the field forward. In the present paper, I argue that an ontological commitment to complex adaptive systems is not only possible, but highly recommended for the study of resilience in development. Such a commitment, however, also comes with a commitment to a different causal ontology and different research methods. In the first part of the paper, I discuss the extent to which current research on resilience in development conceptually adheres to the complex systems perspective. In the second part, I introduce conceptual tools that may help researchers conceptualize causality in complex systems. The third part discusses idiographic methods that could be used in a research program that embraces the interaction dominant causal ontology and idiosyncratic nature of the dynamics of complex systems. The conclusion is that a strong ontological commitment is warranted, but will require a radical departure from nomothetic science.

"What Do You Consider Use?" Perspectives of Black Youth on Cannabis Use

PURPOSE

Adolescent health surveillance systems are critical for understanding patterns of cannabis use; however, their limitations underscore the need for studies that generate new insights, particularly from individuals who are most impacted by negative outcomes. Our objectives were to learn about youths' cannabis use and their perceptions of their peers' cannabis use; their perspectives about trajectories of cannabis use over time and factors that influence trajectories; and perceived risks and benefits associated with cannabis use.

METHODS

A group model building approach was used to gather data about cannabis use from a sample of urban, Black youth. Information about participants' cannabis use was assessed on eligibility screener, enrollment survey, and through structured activities over the course of four group model building workshops.

RESULTS

Participants [(n = 20) mean age 18; 35% male and 95% Black] exclusively used the terms weed and blunts for cannabis. Youth who consume peers' blunts would not characterize themselves as cannabis users. Collectively, youth estimated the majority of Baltimore youth used cannabis by age 16 and that most used daily. Youth described cannabis as more beneficial than harmful. There were no gender differences in prevalence of use, but there were gender dynamics to shared use.

DISCUSSION

Participatory research with urban, Black youth suggests youths' perceptions are misaligned with the ways that researchers conceptualize cannabis use. To better understand the scope of youth cannabis use and its harms, it is critical to leverage input from youth with lived experience to ensure survey tools adequately capture the way youth see themselves using cannabis.

System Dynamic Model Simulates the Growth Trend of Diabetes Mellitus in Chinese Population: Implications for Future Urban Public Health Governance

Objectives: To simulate the growth trend of diabetes mellitus in Chinese population. Methods: The system dynamic modeling methodology was used to establish a population prediction model of diabetes with or without cardiovascular diseases. Lifestyle therapy and the use of metformin, acarbose, and voglibose were assumed to be intervention strategy. The outcomes will be examined at 5, 15, and 30 years after 2020. Results: The projected number of diabetic population in China would increase rapidly from 141.65 million in 2020 to 202.84 million in 2050. Diabetic patients with cardiovascular disease would rapidly increase from 65.58 million in 2020 to 122.88 million by 2050. The annual cost for the entire population with diabetes mellitus in China would reach 182.55 billion by 2050. When the treatment of cardiovascular disease was considered, expenditure was 1.5-2.5-fold higher. Lifestyle therapy and the use of metformin, acarbose and voglibose could effectively slow the growth of the diabetic population. Conclusion: The diabetic population in China is expected to increase rapidly, and diabetic patients with cardiovascular disease will increase greatly. Interventions could delay it.

A systems framework depicting how complex neighborhood dynamics and contextual factors could impact the effectiveness of an alcohol outlet zoning policy

An updated zoning policy eliminating all alcohol outlets (liquor stores) in residential districts was implemented to reduce high rates of violent crime in Baltimore City. Diverse stakeholders were engaged in group model building (GMB) activities to develop causal loop diagrams (CLDs) that elucidate the impact of the new zoning policy on crime, and more broadly, the potentially unintended social and environmental consequences of the policy. Three distinct groups, community advocates, city officials/academics, and community residents, participated in three separate GMB sessions. Three CLDs, one from each stakeholder group, were created to depict the possible outcomes of the zoning policy. Our findings offer insight into potential unintended consequences of removing liquor stores from residential areas that may undermine the policy. Community members described the need for additional supports related to mental health and substance use, opportunities for investment in the community, access to other goods and services, and community-police relations to ensure the policy achieved its intended goal of reducing violent crime. Our findings highlight the importance of timely engagement of local stakeholders to understand how complex neighborhood dynamics and contextual factors could impact the effectiveness of a zoning policy change.

Exploring ways to respond to rising obesity and diabetes in the Caribbean using a system dynamics model

Diabetes and obesity present a high and increasing burden of disease in the Caribbean that have failed to respond to prevention policies and interventions. These conditions are the result of a complex system of drivers and determinants that can make it difficult to predict the impact of interventions. In partnership with stakeholders, we developed a system dynamics simulation model to map the system driving diabetes and obesity prevalence in the Caribbean using Jamaica as a test case. The study aims to use the model to assess the magnitude changes necessary in physical activity and dietary intake to achieve global targets set by the WHO Global Action plan and to test scenarios for interventions to reduce the burden of diabetes and obesity. Continuing current trends in diet, physical activity, and demographics, the model predicts diabetes in Jamaican adults (20+ years) to rise from 12% in 2018 to 15.4% in 2030 and 20.9% by 2050. For obesity, it predicts prevalence to rise from 28.6% in 2018 to 32.1% by 2030 and 39.2% by 2050. The magnitude change necessary to achieve the global targets set by the World Health Organization is so great as to be unachievable. However, a combination of measures both upstream (including reducing the consumption of sugar sweetened beverages and ultra processed foods, increasing fruit and vegetable intake, and increasing moderate-to-vigorous activity) at the population level, and downstream (targeting people at high risk and with diabetes) can significantly reduce the future burden of diabetes and obesity in the region. No single intervention reduces the prevalence of these conditions as much as a combination of interventions. Thus, the findings of this model strongly support adopting a sustained and coordinated approach across various sectors to synergistically maximise the benefits of interventions.

Applications of System Dynamics Models in Chronic Disease Prevention: A Systematic Review

Introduction

Chronic disease is a serious health problem worldwide. Given that health care resources are limited, a comprehensive, effective, and affordable way is needed to provide insights to prevent chronic diseases. System dynamics models provide a comprehensive and systematic method that can predict results over time. These models can simulate and predict appropriate prevention measures for chronic diseases to determine the best practice.

Methods

Two researchers (Y.W., B.H.) independently searched databases (PubMed, Web of Science, Scopus, and Embase) for full-text articles published from January 2000 through February 2021. A PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) 2020–compliant search was carried out to review system dynamics models of chronic disease prevention. A total of 34 articles were included in our study.

Results

We divided the prevention measures of system dynamics models into 2 main categories: upstream prevention and downstream prevention. Upstream prevention measures include lifestyle (eg, tobacco control, balanced diet, mental health, moderate exercise), obesity prevention, and social factors. Downstream prevention measures include clinical treatment of chronic diseases. Results showed that effective upstream prevention measures could reduce the prevalence of chronic diseases, and downstream prevention measures could reduce the incidence of complications, improve quality of life, prolong life, save medical costs, and reduce mortality.

Conclusion

To our knowledge, our systematic review is the first to evaluate the application of system dynamics models in preventing chronic diseases. Such models can provide effective simulations. Hence, we can use system dynamics models to design and implement effective prevention measures for people with chronic diseases.

Systems science for developing policy to improve physical activity, the Caribbean

The World Health Organization (WHO) Global Action Plan on Physical Activity recommends adopting a systems approach to implementing and tailoring actions according to local contexts. We held group model-building workshops with key stakeholders in the Caribbean region to develop a causal loop diagram to describe the system driving the increasing physical inactivity in the region and envision the most effective ways of intervening in that system to encourage and promote physical activity. We used the causal loop diagram to inform how the WHO Global Action Plan on Physical Activity might be adapted to a local context. Although the WHO recommendations aligned well with our causal loop diagram, the diagram also illustrates the importance of local context in determining how interventions should be coordinated and implemented. Some interventions included creating safe physical activity spaces for both sexes, tackling negative attitudes to physical activity in certain contexts, including in schools and workplaces, and improving infrastructure for active transport. The causal loop diagram may also help understand how policies may be undermined or supported by key actors or where policies should be coordinated. We demonstrate how, in a region with a high level of physical inactivity and low resources, applying systems thinking with relevant stakeholders can help the targeted adaptation of global recommendations to local contexts.

An Innovative Approach for Decision-Making on Designing Lifestyle Programs to Reduce Type 2 Diabetes on Dutch Population Level Using Dynamic Simulations

The number of individuals suffering from type 2 diabetes is dramatically increasing worldwide, resulting in an increasing burden on society and rising healthcare costs. With increasing evidence supporting lifestyle intervention programs to reduce type 2 diabetes, and the use of scenario simulations for policy support, there is an opportunity to improve population interventions based upon cost–benefit analysis of especially complex lifestyle intervention programs through dynamic simulations. In this article, we used the System Dynamics (SD) modeling methodology aiming to develop a simulation model for policy makers and health professionals to gain a clear understanding of the patient journey of type 2 diabetes mellitus and to assess the impact of lifestyle intervention programs on total cost for society associated with prevention and lifestyle treatment of pre-diabetes and type 2 diabetes in The Netherlands. System dynamics describes underlying structure in the form of causal relationships, stocks, flows, and delays to explore behavior and simulate scenarios, in order to prescribe intervention programs. The methodology has the opportunity to estimate and simulate the consequences of unforeseen interactions in order to prescribe intervention programs based on scenarios tested through “what-if” experiments. First, the extensive knowledge of diabetes, current available data on the type 2 diabetes population, lifestyle intervention programs, and associated cost in The Netherlands were captured in one simulation model. Next, the relationships between leverage points on the growth of type 2 diabetes population were based upon available data. Subsequently, the cost and benefits of future lifestyle intervention programs on reducing diabetes were simulated, identifying the need for an integrated adaptive design of lifestyle programs while collecting the appropriate data over time. The strengths and limitations of scenario simulations of complex lifestyle intervention programs to improve the (cost)effectiveness of these programs to reduce diabetes in a more sustainable way compared to usual care are discussed.

A System Dynamics Simulation Applied to Healthcare: A Systematic Review

In recent years, there has been significant interest in developing system dynamics simulation models to analyze complex healthcare problems. However, there is a lack of studies seeking to summarize the available papers in healthcare and present evidence on the effectiveness of system dynamics simulation in this area. The present paper draws on a systematic selection of published literature from 2000 to 2019, in order to form a comprehensive view of current applications of system dynamics methodology that address complex healthcare issues. The results indicate that the application of system dynamics has attracted significant attention from healthcare researchers since 2013. To date, articles on system dynamics have focused on a variety of healthcare topics. The most popular research areas among the reviewed papers included the topics of patient flow, obesity, workforce demand, and HIV/AIDS. Finally, the quality of the included papers was assessed based on a proposed ranking system, and ways to improve the system dynamics models' quality were discussed.

Using Group Model Building to Describe the System Driving Unhealthy Eating and Identify Intervention Points: A Participatory, Stakeholder Engagement Approach in the Caribbean

Many Small Island Developing States of the Caribbean experience a triple burden of malnutrition with high rates of obesity, undernutrition in children, and iron deficiency anemia in women of reproductive age, driven by an inadequate, unhealthy diet. This study aimed to map the complex dynamic systems driving unhealthy eating and to identify potential points for intervention in three dissimilar countries. Stakeholders from across the food system in Jamaica (n = 16), St. Kitts and Nevis (n = 19), and St. Vincent and the Grenadines (n = 6) engaged with researchers in two group model building (GMB) workshops in 2018. Participants described and mapped the system driving unhealthy eating, identified points of intervention, and created a prioritized list of intervention strategies. Stakeholders were also interviewed before and after the workshops to provide their perspectives on the utility of this approach. Stakeholders described similar underlying systems driving unhealthy eating across the three countries, with a series of dominant feedback loops identified at multiple levels. Participants emphasized the importance of the relative availability and price of unhealthy foods, shifting cultural norms on eating, and aggressive advertising from the food industry as dominant drivers. They saw opportunities for governments to better regulate advertising, disincentivize unhealthy food options, and bolster the local agricultural sector to promote food sovereignty. They also identified the need for better coordinated policy making across multiple sectors at national and regional levels to deliver more integrated approaches to improving nutrition. GMB proved to be an effective tool for engaging a highly diverse group of stakeholders in better collective understanding of a complex problem and potential interventions.

Validating the self-reported annual monitoring grid for the 2007 Caribbean Community Declaration of Port-of-Spain on noncommunicable diseases

Objectives

In 2007, the Caribbean Community (CARICOM) convened the world's first-ever heads of government summit on noncommunicable diseases (NCDs) and issued the landmark Declaration of Port-of-Spain: Uniting to Stop the Epidemic of Chronic NCDs. Since then, ministry of health (MoH) focal points in each country have self-reported annually on their NCD efforts, using a 26-indicator grid created to assess implementation of the Declaration. Our objective was to assess the validity of those grid responses, as compared to information from in-depth interviews and document reviews.

Methods

Seven national case studies on policy responses to the Declaration were undertaken in 2015. In-depth, semistructured interviews were conducted with stakeholders from multiple sectors, including the MoH. Policy documents were also identified and reviewed. The results from the 2015 case studies were compared to the 2014 MoH focal point grid responses. Kappa statistics evaluated chance agreement.

Results

The information from the grid and from the case studies agreed closely. Out of a total of 182 indicators (26 each for seven countries), there was a lack of agreement on just 9 (4.9%). All the differences were between policy statements and implementation. Except for physical activity, kappa statistics indicated that agreement was good to excellent for all the clusters of the grid and for the grid as a whole, but with wide confidence intervals.

Conclusions

In general, the monitoring grid accurately assessed the national situation, but with a possible tendency to overstate performance in some areas. These findings contributed to the design of a new, 50-indicator monitoring grid in 2016. Alongside these improvements, CARICOM countries face a substantial burden from having to complete many other required NCD reports, mainly for the Pan American Health Organization and the World Health Organization.

Simulation modeling to assist with childhood obesity control: perceptions of Baltimore City policymakers

Computational simulation models have potential to inform childhood obesity prevention efforts. To guide their future use in obesity prevention policies and programs, we assessed Baltimore City policymakers' perceptions of computational simulation models. Our research team conducted 15 in-depth interviews with stakeholders (policymakers in government and non-profit sectors), then transcribed and coded them for analysis. We learned that informants had limited understanding of computational simulation modeling. Although they did not understand how the model was developed, they perceived the tool to be useful when applying for grants, adding to the evidence base for decision-making, piloting programs and policies, and visualizing data. Their concerns included quality and relevance of data used to support the model. Key recommendations for model design included a visual display with explanations to facilitate understanding and a formal method for gathering feedback during model development.