Using agent-based modeling to study multiple risk factors and multiple health outcomes at multiple levels

A scoping review of systems approaches for increasing physical activity in populations

INTRODUCTION

The past decade has increasingly seen systems approaches as a featured theme in public health studies and policy documents. This trend is evident in the area of physical activity, which is a significant global health risk factor that is addressed in WHO's Global Action Plan on Physical Activity. We undertook a comprehensive scoping review to characterize the application of systems approaches to physical activity, to develop a typology of the objectives, themes and methods of research papers that purported to apply systems thinking to this issue.

METHODS

We searched electronic databases (PubMed, Web of Science, Scopus and PsycINFO) for studies published during the period 2010-2021 that explicitly applied systems approaches or methods to investigate and/or address population physical activity. A framework using systems-based methodological approaches was adapted to classify physical activity studies according to their predominant approach, covering basic descriptive, complex analytical and advanced forms of practice. We selected case studies from retained studies to depict the current "state of the art".

RESULTS

We included 155 articles in our narrative account. Literature reporting the application of systems approaches to physical activity is skewed towards basic methods and frameworks, with most attention devoted to conceptual framing and predictive modelling. There are few well-described examples of physical activity interventions which have been planned, implemented and evaluated using a systems perspective. There is some evidence of "retrofitted" complex system framing to describe programmes and interventions which were not designed as such.

DISCUSSION

We propose a classification of systems-based approaches to physical activity promotion together with an explanation of the strategies encompassed. The classification is designed to stimulate debate amongst policy-makers, practitioners and researchers to inform the further implementation and evaluation of systems approaches to physical activity.

CONCLUSION

The use of systems approaches within the field of physical activity is at an early stage of development, with a preponderance of descriptive approaches and a dearth of more complex analyses. We need to see movement towards a more sophisticated research agenda spanning the development, implementation and evaluation of systems-level interventions.

Agent-based Modeling in Tobacco Regulatory Science: Exploring 'What if' in Waterpipe Smoking

Objectives

Waterpipe tobacco smoking (WTS) is an emerging public health crisis, particularly among youth and young adults. Different from the use of other tobacco products and e-cigarettes, WTS tends to be a social activity occurring among friends or persons associated with social networks. In this paper, we review a potential strategy for WTS-related research.

Methods

As a bottom-up computational model, agent-based modeling (ABM) can simulate the actions and interactions of agents, as well as the dynamic interactions between agents and their environments, to gain an understanding of the functioning of a system. ABM is particularly useful for incorporating the influence of social networks in WTS, and capturing people's space-time activity and the spatial distribution of WTS venues.

Results

Comprehensive knowledge of WTS-related behaviors at the individual level is needed to take advantage of ABM and use it to examine policies such as the interaction between WTS and cigarette smoking and the effect of flavors used in waterpipe tobacco. Longitudinal and WTS-specific surveys and laboratory experiments are particularly helpful to understand WTS basic mechanisms and elicit individual preferences, respectively.

Conclusions

We argue that the uniqueness of WTS makes ABM a promising tool to be used in WTS-related research, as well as understanding use of other tobacco products.

A narrative review of the use of agent-based modeling in health behavior and behavior intervention

Studies of health behaviors and behavior intervention have begun to explore the potential of agent-based modeling (ABM). A review of how ABMs have been used in health behavior, behavior intervention, and corresponding insights is warranted. The goal of this study was to provide a narrative review of the applications of ABMs in health behavior change and intervention. I will focus on two perspectives: (a) the mechanism of behavior and behavior change and (b) ABMs' use for behavior intervention. I identified and reviewed 17 ABMs applied to behaviors including physical activity, diet, alcoholic drinking, smoking, and drug use. Among these ABMs, I grouped their mechanisms of behavior change into four categories and evaluated the advantages and disadvantages of each mechanism. For behavior intervention, I evaluated the use of ABMs on levels of individual, interpersonal, and neighborhood environment. Various behavior change mechanisms and simplifications existed because of our limited knowledge of behaviors at the individual level. Utility maximization was the most frequently used mechanism. ABMs offered insights for behavior intervention including the benefits of upstream interventions and multilevel intervention, as well as balances among various factors, outcomes, and populations. ABMs have been used to model a diversity of behaviors, populations, and interventions. The use of ABMs in health behavior is at an early stage, and a major challenge is our limited knowledge of behaviors at the individual level.

Depression and alcohol misuse among older adults: exploring mechanisms and policy impacts using agent-based modelling

PURPOSE

To: (1) explore how multi-level factors impact the longitudinal prevalence of depression and alcohol misuse among urban older adults (≥ 65 years), and (2) simulate the impact of alcohol taxation policies and targeted interventions that increase social connectedness among excessive drinkers, socially isolated and depressed older adults; both alone and in combination.

METHODS

An agent-based model was developed to explore the temporal co-evolution of depression and alcohol misuse prevalence among older adults nested in a spatial network. The model was based on Los Angeles and calibrated longitudinally using data from the Multi-Ethnic Study of Atherosclerosis.

RESULTS

Interventions with a social component targeting depressed and socially isolated older adults appeared more effective in curbing depression prevalence than those focused on excessive drinkers. Targeting had similar impacts on alcohol misuse, though the effects were marginal compared to those on depression. Alcohol taxation alone had little impact on either depression or alcohol misuse trajectories.

CONCLUSIONS

Interventions that improve social connectedness may reduce the prevalence of depression among older adults. Targeting considerations could play an important role in determining the success of such efforts.