Yeeli Mui

B’More healthy communities for kids: design of a multi-level intervention for obesity prevention for low-income African American children

BackgroundChildhood obesity rates in the U.S. have reached epidemic proportions, and an urgent need remains to identify evidence-based strategies for prevention and treatment. Multi-level, multi-component interventions are needed due to the multi-factorial nature of obesity, and its proven links to both the social and built environment. However, there are huge gaps in the literature related to doing these kinds of interventions among low-income, urban, minority groups.MethodsThe B’More Healthy Communities for Kids (BHCK) intervention is a multi-level, multi-component intervention, targeting low-income African American youth ages 10–14 and their families in Baltimore, Maryland. This intervention prevents childhood obesity by working at multiple levels of the food and social environments to increase access to, demand for, and consumption of healthier foods. BHCK works to create systems-level change by partnering with city policy-makers, multiple levels of the food environment (wholesalers, corner stores, carryout restaurants), and the social environment (peers and families). In addition, extensive evaluation will be conducted at each level of the intervention to assess intervention effectiveness via both process and impact measures.DiscussionThis project is novel in multiple ways, including: the inclusion of stakeholders at multiple levels (policy, institutional, and at multiple levels of the food system); that it uses novel computational modeling methodologies to engage policy makers and guide informed decisions of intervention effectiveness; it emphasizes both the built environment (intervening with food sources) and the social environment (intervening with families and peers). The design of the intervention and the evaluation plan of the BHCK project are documented here.Trial registrationNCT02181010 (July 2, 2014).

Incorporating Systems Science Principles into the Development of Obesity Prevention Interventions: Principles, Benefits, and Challenges

Systems modeling represents an innovative approach for addressing the obesity epidemic at the community level. We developed an agent-based model of the Baltimore City food environment that permits us to assess the relative impact of different programs and policies, alone and in combination, and potential unexpected consequences. Based on this experience, and a review of literature, we have identified a set of principles, potential benefits, and challenges. Some of the key principles include the importance of early and multilevel engagement with the community prior to initiating model development and continued engagement and testing with community stakeholders. Important benefits include improving community stakeholder understanding of the system, testing of interventions before implementation, and identification of unexpected consequences. Challenges in these models include deciding on the most important, yet parsimonious factors to consider, how to model food source and food selection behavior in a realistic yet transferable manner, and identifying the appropriate outcomes and limitations of the model.

A systems approach to obesity

Obesity has become a truly global epidemic, affecting all age groups, all populations, and countries of all income levels. To date, existing policies and interventions have not reversed these trends, suggesting that innovative approaches are needed to transform obesity prevention and control. There are a number of indications that the obesity epidemic is a systems problem, as opposed to a simple problem with a linear cause-and-effect relationship. What may be needed to successfully address obesity is an approach that considers the entire system when making any important decision, observation, or change. A systems approach to obesity prevention and control has many benefits, including the potential to further understand indirect effects or to test policies virtually before implementing them in the real world. Discussed here are 5 key efforts to implement a systems approach for obesity prevention: 1) utilize more global approaches; 2) bring new experts from disciplines that do not traditionally work with obesity to share experiences and ideas with obesity experts; 3) utilize systems methods, such as systems mapping and modeling; 4) modify and combine traditional approaches to achieve a stronger systems orientation; and 5) bridge existing gaps between research, education, policy, and action. This article also provides an example of how a systems approach has been used to convene a multidisciplinary team and conduct systems mapping and modeling as part of an obesity prevention program in Baltimore, Maryland.

Longitudinal Associations between Change in Neighborhood Social Disorder and Change in Food Swamps in an Urban Setting

Few studies have examined how neighborhood contextual features may influence the food outlet mix. We evaluated the relationship between changes in neighborhood crime and changes in the food environment, namely the relative density of unhealthy (or intermediate) food outlets out of total food outlets, or food swamp score, in Baltimore City from 2000 to 2012, using neighborhood fixed-effects linear regression models. Comparing neighborhoods to themselves over time, each unit increase in crime rate was associated with an increase in the food swamp score (b = 0.13; 95% CI, −0.00017 to 0.25). The association with food swamp score was in the same direction for violent crime and in the inverse direction for arrests related to juvenile crimes (proxy of reduced crime), but did not reach statistical significance when examined separately. Unfavorable conditions, such as crime, may deter a critical consumer base, diminishing the capacity of a community to attract businesses that are perceived to be neighborhood enhancing. Addressing these more distal drivers may be important for policies and programs to improve these food environments.

Simulating the Impact of Sugar-Sweetened Beverage Warning Labels in Three Cities

INTRODUCTION A number of locations have been considering sugar-sweetened beverage point-of-purchase warning label policies to help address rising adolescent overweight and obesity prevalence. METHODS To explore the impact of such policies, in 2016 detailed agent-based models of Baltimore, Philadelphia, and San Francisco were developed, representing their populations, school locations, and food sources, using data from various sources collected between 2005 and 2014. The model simulated, over a 7-year period, the mean change in BMI and obesity prevalence in each of the cities from sugar-sweetened beverage warning label policies. RESULTS Data analysis conducted between 2016 and 2017 found that implementing sugar-sweetened beverage warning labels at all sugar-sweetened beverage retailers lowered obesity prevalence among adolescents in all three cities. Point-of-purchase labels with 8% efficacy (i.e., labels reducing probability of sugar-sweetened beverage consumption by 8%) resulted in the following percentage changes in obesity prevalence: Baltimore: -1.69% (95% CI= -2.75%, -0.97%, p<0.001); San Francisco: -4.08% (95% CI= -5.96%, -2.2%, p<0.001); Philadelphia: -2.17% (95% CI= -3.07%, -1.42%, p<0.001). CONCLUSIONS Agent-based simulations showed how warning labels may decrease overweight and obesity prevalence in a variety of circumstances with label efficacy and literacy rate identified as potential drivers. Implementing a warning label policy may lead to a reduction in obesity prevalence. Focusing on warning label design and store compliance, especially at supermarkets, may further increase the health impact.

Healthy versus Unhealthy Suppliers in Food Desert Neighborhoods: A Network Analysis of Corner Stores’ Food Supplier Networks

Background: Products in corner stores may be affected by the network of suppliers from which storeowners procure food and beverages. To date, this supplier network has not been well characterized. Methods: Using network analysis, we examined the connections between corner stores (n = 24) in food deserts of Baltimore City (MD, USA) and their food/beverage suppliers (n = 42), to determine how different store and supplier characteristics correlated. Results: Food and beverage suppliers fell into two categories: Those providing primarily healthy foods/beverages (n = 15) in the healthy supplier network (HSN) and those providing primarily unhealthy food/beverages (n = 41) in the unhealthy supplier network (UHSN). Corner store connections to suppliers in the UHSN were nearly two times greater (t = 5.23, p < 0.001), and key suppliers in the UHSN core were more diverse, compared to the HSN. The UHSN was significantly more cohesive and densely connected, with corner stores sharing a greater number of the same unhealthy suppliers, compared to HSN, which was less cohesive and sparsely connected (t = 5.82; p < 0.001). Compared to African Americans, Asian and Hispanic corner storeowners had on average −1.53 (p < 0.001) fewer connections to suppliers in the HSN (p < 0.001). Conclusions: Our findings indicate clear differences between corner stores’ HSN and UHSN. Addressing ethnic/cultural differences of storeowners may also be important to consider.

Where Do Low-Income Children Get Food? Combining Ground-Truthing and Technology to Improve Accuracy in Establishing Children’s Food Purchasing Behaviors

Developing nutrition-focused environmental interventions for youth requires accurate assessment of where they purchase food. We have developed an innovative, technology-based method to improve the accuracy of food source recall among children using a tablet PC and ground-truthing methodologies. As part of the B’more Healthy Communties for Kids study, we mapped and digitally photographed every food source within a half-mile radius of 14 Baltimore City recreation centers. This food source database was then used with children from the surrounding neighborhoods to search for and identify the food sources they frequent. This novel integration of traditional data collection and technology enables researchers to gather highly accurate information on food source usage among children in Baltimore City.

Relationships between Vacant Homes and Food Swamps: A Longitudinal Study of an Urban Food Environment

Research indicates that living in neighborhoods with high concentrations of boarded-up vacant homes is associated with premature mortality due to cancer and diabetes, but the mechanism for this relationship is unclear. Boarded-up housing may indirectly impact residents’ health by affecting their food environment. We evaluated the association between changes in vacancy rates and changes in the density of unhealthy food outlets as a proportion of all food outlets, termed the food swamp index, in Baltimore, MD (USA) from 2001 to 2012, using neighborhood fixed-effects linear regression models. Over the study period, the average food swamp index increased from 93.5 to 95.3 percentage points across all neighborhoods. Among non-African American neighborhoods, increases in the vacancy rate were associated with statistically significant decreases in the food swamp index (b = −0.38; 90% CI, −0.64 to −0.12; p-value: 0.015), after accounting for changes in neighborhood SES, racial diversity, and population size. A positive association was found among low-SES neighborhoods (b = 0.15; 90% CI, 0.037 to 0.27; p-value: 0.031). Vacant homes may influence the composition of food outlets in urban neighborhoods. Future research should further elucidate the mechanisms by which more distal, contextual factors, such as boarded-up vacant homes, may affect food choices and diet-related health outcomes.

Process Evaluation and Lessons Learned From Engaging Local Policymakers in the B’More Healthy Communities for Kids Trial:

Partnerships linking researchers to the policymaking process can be effective in increasing communication and supporting health policy. However, these policy partnerships rarely conduct process evaluation. The Policy Working Group (Policy WG) was the policy-level intervention of the multilevel B’More Healthy Communities for Kids (BHCK) trial. The group sought to align interests of local policymakers, inform local food and nutrition policy, introduce policymakers to a new simulation modeling, and sustain intervention levels of BHCK. We conducted an evaluation on the Policy WG between July 2013 and May 2016. We evaluated process indicators for reach, dose-delivered, and fidelity and developed a SWOT (strengths, weaknesses, opportunities, and threats) analysis. The policy intervention was implemented with high reach and dose-delivered. Fidelity measures improved from moderate to nearly high over time. The number of health-related issues on policymakers’ agenda increased from 50% in the first 2 years to 150% of the high standard in Year 3. SWOT analysis integrated a stakeholder feedback survey to consider areas of strength, weakness, opportunity, and threats. Although the fidelity of the modeling was low at 37% of the high standard, stakeholders indicated that the simulation modeling should be a primary purpose for policy intervention. Results demonstrate that process evaluation and SWOT analysis is useful for tracking the progress of policy interventions in multilevel trials and can be used to monitor the progress of building partnerships with policymakers.