A scoping review of simulation modeling in built environment and physical activity research: Current status, gaps, and future directions for improving translation

Simulated retail food environments: A literature review of systems science approaches to advance equity in access to healthy diets

As researchers increasingly utilize systems science simulation modeling (SSSM), little is known about how and by whom SSSMs are being leveraged to address inequities in access to healthy diets. We evaluated the extent to which studies (n = 66) employing SSSM to examine retail food environments (RFEs): included three pillars of equity (social position, human capital, socioeconomic and political context) that shape RFEs and access to healthy diets; grounded model design and development in theory; engaged with diverse stakeholders and lived experiences related to RFEs; and translated model findings towards addressing inequities in RFEs. Most studies (n = 58) included some model characteristics related to social position (e.g., age). Characteristics related to human capital (e.g., meal planning skills) were the least integrated fundamental pillar (n = 15). All studies included some characteristics related to socioeconomic and political context; however, we found little to no incorporation of social contexts (e.g., cultural and societal norms). Regarding model design and development, less than one-third of studies specified theoretical frameworks or engaged with local domain experts and stakeholders. While certain research objectives and, consequently, model types lend themselves better than others to address key pillars that influence RFEs, findings show that models are not fully leveraging SSSMs to analyze the multiple, interacting dimensions - particularly social phenomena - influencing equity in access to healthy diets. Greater attention to engaging stakeholders and the role of human capital and social contexts will likely better equip models to more holistically examine equitable food access, including essential pathways and unintended consequences of programs and policies.

The long-term effectiveness and cost-effectiveness of public health interventions; how can we model behavior? A review

The effectiveness and cost of a public health intervention is dependent on complex human behaviors, yet health economic models typically make simplified assumptions about behavior, based on little theory or evidence. This paper reviews existing methods across disciplines for incorporating behavior within simulation models, to explore what methods could be used within health economic models and to highlight areas for further research. This may lead to better-informed model predictions. The most promising methods identified which could be used to improve modeling of the causal pathways of behavior-change interventions include econometric analyses, structural equation models, data mining and agent-based modeling; the latter of which has the advantage of being able to incorporate the non-linear, dynamic influences on behavior, including social and spatial networks. Twenty-two studies were identified which quantify behavioral theories within simulation models. These studies highlight the importance of combining individual decision making and interactions with the environment and demonstrate the importance of social norms in determining behavior. However, there are many theoretical and practical limitations of quantifying behavioral theory. Further research is needed about the use of agent-based models for health economic modeling, and the potential use of behavior maintenance theories and data mining.

Simulation models of sugary drink policies: A scoping review

INTRODUCTION

Simulation modeling methods are an increasingly common tool for projecting the potential health effects of policies to decrease sugar-sweetened beverage (SSB) intake. However, it remains unknown which SSB policies are understudied and how simulation modeling methods could be improved. To inform next steps, we conducted a scoping review to characterize the (1) policies considered and (2) major characteristics of SSB simulation models.

METHODS

We systematically searched 7 electronic databases in 2020, updated in 2021. Two investigators independently screened articles to identify peer-reviewed research using simulation modeling to project the impact of SSB policies on health outcomes. One investigator extracted information about policies considered and key characteristics of models from the full text of included articles. Data were analyzed in 2021-22.

RESULTS

Sixty-one articles were included. Of these, 50 simulated at least one tax policy, most often an ad valorem tax (e.g., 20% tax, n = 25) or volumetric tax (e.g., 1 cent-per-fluid-ounce tax, n = 23). Non-tax policies examined included bans on SSB purchases (n = 5), mandatory reformulation (n = 3), warning labels (n = 2), and portion size policies (n = 2). Policies were typically modeled in populations accounting for age and gender or sex attributes. Most studies focused on weight-related outcomes (n = 54), used cohort, lifetable, or microsimulation modeling methods (n = 34), conducted sensitivity or uncertainty analyses (n = 56), and included supplementary materials (n = 54). Few studies included stakeholders at any point in their process (n = 9) or provided replication code/data (n = 8).

DISCUSSION

Most simulation modeling of SSB policies has focused on tax policies and has been limited in its exploration of heterogenous impacts across population groups. Future research would benefit from refined policy and implementation scenario specifications, thorough assessments of the equity impacts of policies using established methods, and standardized reporting to improve transparency and consistency.

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.

Applications of Complex Systems Models to Improve Retail Food Environments for Population Health: A Scoping Review

Retail food environments (RFEs) are complex systems with important implications for population health. Studying the complexity within RFEs comes with challenges. Complex systems models are computational tools that can help. We performed a systematic scoping review of studies that used complex systems models to study RFEs for population health. We examined the purpose for using the model, RFE features represented, extent to which the complex systems approach was maximized, and quality and transparency of methods employed. The PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) guidelines were followed. Studies using agent-based modeling, system dynamics, discrete event simulations, networks, hybrid, or microsimulation models were identified from 7 multidisciplinary databases. Fifty-six studies met the inclusion criteria, including 23 microsimulation, 13 agent-based, 10 hybrid, 4 system dynamics, 4 network, and 2 discrete event simulation models. Most studies (n = 45) used models for experimental purposes and evaluated effects of simulated RFE policies and interventions. RFE characteristics simulated in models were diverse, and included the features (e.g., prices) customers encounter when shopping (n = 55), the settings (e.g., restaurants, supermarkets) where customers purchase food and beverages (n = 30), and the actors (e.g., store managers, suppliers) who make decisions that influence RFEs (n = 25). All models incorporated characteristics of complexity (e.g., feedbacks, conceptual representation of multiple levels), but these were captured to varying degrees across model types. The quality of methods was adequate overall; however, few studies engaged stakeholders (n = 10) or provided sufficient transparency to verify the model (n = 12). Complex systems models are increasingly utilized to study RFEs and their contributions to public health. Opportunities to advance the use of these approaches remain, and areas to improve future research are discussed. This comprehensive review provides the first marker of the utility of leveraging these approaches to address RFEs for population health.

Taxonomy and model for valuing the contribution of digital water meters to sustainability objectives

Water security is an issue across the world as communities face ageing infrastructure, population increases and climate change. The application of digital water metering (DWM) to properties has had a demonstrable impact on water savings at the property and network levels, on efficiencies within water utilities, as well as on improvements to customer satisfaction scores. Gathering and processing near-real-time water usage data is very important for both end-users and utilities, as well as demand and supply management planning. The potential contribution of DWM to the three pillars of water sustainability (environmental, economic development and social equity) is often overlooked. In Australia and other jurisdictions water utilities are facing up to the challenge of climate change. However, business cases promoting DWM are often unsuccessful because the benefit side falls short of the cost side. This study sought to identify possible DWM benefits not previously considered through an extensive review of academic and industry literature, and then to view those benefits through the lens of sustainability. The 77 identified benefits of DWM were catalogued and a taxonomy was created. The study elicited the opinions of experts, before quantifying them, thus identifying two distinct contexts of benefit value; subsequently, it surveyed the views of customers and developed a stochastic model of benefit value. The model, named DWM360, was applied to the project data of a large metropolitan water utility in Australia to model their DWM proposal for cost savings, contribution to sustainability and uplift in customer satisfaction. This paper presents a novel focus on how the benefits of DWM assist water sustainability. It considers differing social norms that impact consumer acceptance of changes in metering and water charges. The study will be of interest to researchers as well as practitioners looking to identify sustainability aspects of DWM.