Income variability and incident cardiovascular disease in diabetes: a population-based cohort study.

BACKGROUND AND AIMS: Longitudinal change in income is crucial in explaining cardiovascular health inequalities. However, there is limited evidence for cardiovascular disease (CVD) risk associated with income dynamics over time among individuals with type 2 diabetes (T2D). METHODS: Using a nationally representative sample from the Korean National Health Insurance Service database, 1 528 108 adults aged 30-64 with T2D and no history of CVD were included from 2009 to 2012 (mean follow-up of 7.3 years). Using monthly health insurance premium information, income levels were assessed annually for the baseline year and the four preceding years. Income variability was defined as the intraindividual standard deviation of the percent change in income over 5 years. The primary outcome was a composite event of incident fatal and nonfatal CVD (myocardial infarction, heart failure, and stroke) using insurance claims. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated after adjusting for potential confounders. RESULTS: High-income variability was associated with increased CVD risk (HRhighest vs. lowest quartile 1.25, 95% CI 1.22-1.27; Ptrend < .001). Individuals who experienced an income decline (4 years ago vs. baseline) had increased CVD risk, which was particularly notable when the income decreased to the lowest level (i.e. Medical Aid beneficiaries), regardless of their initial income status. Sustained low income (i.e. lowest income quartile) over 5 years was associated with increased CVD risk (HRn = 5 years vs. n = 0 years 1.38, 95% CI 1.35-1.41; Ptrend < .0001), whereas sustained high income (i.e. highest income quartile) was associated with decreased CVD risk (HRn = 5 years vs. n = 0 years 0.71, 95% CI 0.70-0.72; Ptrend < .0001). Sensitivity analyses, exploring potential mediators, such as lifestyle-related factors and obesity, supported the main results. CONCLUSIONS: Higher income variability, income declines, and sustained low income were associated with increased CVD risk. Our findings highlight the need to better understand the mechanisms by which income dynamics impact CVD risk among individuals with T2D.

Where the children play: Gender gaps in recess physical activity by age and playground area.

Objective: Recess contributes meaningfully to physical activity (PA), but recess time has declined. The study's purpose was to report PA by age, gender, and playground feature to inform potential playground configurations more conducive to PA during recess. Methods: Using the System for Observing Play and Leisure Activity in the Youth, kindergarten through 5th grade recesses were observed on at least four days at four schools in Little Rock, Arkansas, United States during May 2023. Target playground features were ball courts, grass, pavement, play structures, and swings. To provide inferential analysis, a comparison of conditional means across playground features, age, and gender was conducted using linear regression with robust standard errors clustered by school. Results: 3,356 playground scans (intercoder correlation = 0.93) were collected and aggregated by school, day, gender, age (grade), and target feature for a sample size of 292 observations. The gender gap was widest among 4-5th graders, 79 % (95 % CI: 72, 86) for males and 64 % (95 % CI: 58, 70) for females. Among females, PA was highest on swings [82 % (95 % CI: 77, 86)] and lowest on paved areas [56 % (95 % CI: 43, 69)]. Among males, it was highest on both swings [81 % (95 % CI: 75, 86)] and ball courts [83 % (95 % CI: 77, 89)] and lowest on grassy areas [64 % (95 % CI: 60, 67)]. Conclusion: Swings, courts, and play structures were associated with a higher proportion of children being engaged in PA. Research is needed to identify whether physical improvements to facilitate access to these features increase PA.

Evaluation of the Little Rock Green Schoolyard initiative: a quasi-experimental study protocol.

BACKGROUND: Evidence suggests that access to green schoolyards may facilitate vigorous play and lead to increased physical activity, which could lead to improved academic outcomes and reduce excess childhood weight gain. Greener schoolyards can also provide additional outdoor amenities that help the community at large. The Little Rock Green Schoolyard Initiative, a program aiming to promote outdoor learning and play in two of the city's community schools, provides a natural experiment to evaluate the role of such interventions. This article presents the protocols and study plans that will be used to evaluate this community-led initiative on several outcomes including physical activity, sleep quality, use of schoolgrounds, and perceptions of the school environment. Administrative datasets will be used to assess exposure to green schoolyard improvements on academic achievement, attendance, and disciplinary referrals during elementary school. METHODS: Data will be gathered in two community schools where the green schoolyard improvements are taking place and in two demographically-matched comparison schools located elsewhere within the Little Rock School District. Data will be collected before, during, and after the green schoolyard improvements go into effect. Physical activity and sleep quality will be measured using actigraphy. Physical activity will also be assessed through direct playground observations during recess and outside of school hours. During the final year of the study, administrative data will be assembled and evaluated using difference-in-differences estimation and synthetic controls, two causal inference methods from the program evaluation literature. DISCUSSION: The study is designed to provide new insights into the design, implementation, and evaluation of playgrounds among schoolchildren, especially those who are at risk of developing severe obesity during their elementary school years. The research herein will develop empirical data, elucidate potential mechanisms, and practical experience for future study, policymaking, and health services.

Evaluation of Delivering Breakfast After the Bell and Academic Performance Among Third-Grade Children: An Application of the Synthetic Control Method.

BACKGROUND: Breakfast after the bell (BAB), an alternative way to deliver breakfast after the school day begins, has been shown to increase participation in the School Breakfast Program. However, BAB occupies time that could otherwise be used for instruction and may affect academic performance. This study examined whether BAB affects math and literacy scores in third grade, an age not adequately studied in earlier literature. METHODS: Using data on Arkansas students, we compared schools adopting BAB to corresponding "synthetic" control schools by minimizing preadoption differences in observables that can influence test scores. RESULTS: We found little evidence of positive or negative effects on test scores. We also found little evidence of meaningful program effects over subsamples of schools by district enrollment size and BAB delivery method. Schools that adopted grab-and-go delivery and schools in districts with small enrollments, less than 600 students, showed statistically negative effects on math after BAB adoption. However, these effects were transitory and no longer present by the time the first fully exposed cohort reached third grade. CONCLUSIONS: BAB can be incorporated into the school day without adversely impacting academic achievement, especially if adopting schools seek input from educators and nutrition personnel already experienced with BAB.

Impact of Weight Status Reporting on Childhood Body Mass Index.

Background: Many states have adopted school-based BMI screening or surveillance programs in an effort to address high rates of childhood obesity, some of which involve provision of confidential BMI reports to parents. While there is evidence that parents are attuned to information in the reports, there is less evidence showing that the reports are effective in preventing excess childhood weight gain. Methods: Data from Arkansas, the state with the nation's first and longest running and BMI screening program, were used to measure the impact of BMI reports. This was done through a regression discontinuity design that compared future BMI z-scores among children falling within a narrow band around the obese and overweight thresholds. We derived the effects of BMI reports by comparing students who received different types of reports around the relevant threshold. Results: While we are unable to detect any differences in BMI z-scores between the children who received the overweight report and the children who received the healthy weight report, we detected some differences between children who received the obese report and children who received the overweight report. These findings hold across subsamples by age, minority status, and school meal status. Conclusions: Based on these data, overweight or obese reports to do not meaningfully impact future BMI z-scores. This may be due, in part, to the format of parental reports, which may dampen the surprise element of an overweight or obese report.

Food insecurity during the COVID-19 pandemic: evidence from a survey of low-income Americans.

The COVID-19 pandemic significantly increased food insecurity despite emergency legislation that put more resources into food assistance programs, increased unemployment benefits, and provided stimulus payments. We conducted a survey in the US on food insecurity among low-income Americans during the early months of the pandemic. While we cannot estimate causal effects, we are able to show important associations between food insecurity and nutritional and economic assistance that highlight the need to ensure that those newly at risk for food insecurity are able to connect to resources. For example, our results indicate that those who lost jobs due to the pandemic reported the highest level of food insecurity and also the lowest engagement with food assistance programs. The SNAP expansion appears to be important only among groups with higher levels of income stability including non-minority households and those not experiencing a job loss. Thus, the SNAP expansion may not have had a meaningful impact on those most at risk for food insecurity. Finally, our data highlight the importance of school meal programs during normal times. Those who took advantage of school meals before the outbreak are more likely to have experienced food insecurity during the pandemic-related school closures.

The effect of gender-specific labor market conditions on children's weight.

BACKGROUND: Macroeconomic conditions are widely known to influence health outcomes through direct behavioral change or indirect mental effects of individuals. However, they have not received much attention in relation to childhood obesity. METHODS: Using gender-specific predicted employment growth rates as an index for labor market conditions, we analyze how economic shocks affect children's weight status in Arkansas. To understand the underlying mechanisms behind these results, we use data on individual time use to examine how economic shocks are related to activities related to children's weight. RESULTS: Improvement in the female labor market is associated with an increase in body mass index (BMI) and the probability that a child is overweight or obese, while an improvement in the male labor market has no significant effects on children's weight. This impact is particularly evident among female children, older children, and African-American children. We also find a negative effect of improvements in the female labor market on time spent on preparation for foods at home. CONCLUSIONS: These results suggest that a decrease in time spent preparing home-cooked foods might be a plausible explanation for the pro-cyclical relationship between children's weight and improvement in the labor market conditions. Thus, the policy implications of our paper should be aimed at mitigating the adverse effects of women's labor participation.

A longitudinal analysis of fast-food exposure on child weight outcomes: Identifying causality through school transitions.

This article investigates the effect of fast-food availability on childhood weight outcomes by gender, race, and location. We use a novel identification strategy based on changes in fast-food exposure along the route between the home and school that occur as students progress through the public school system and transition to different types of schools, e.g. from elementary school to intermediate school or from intermediate school to high school. Using a longitudinal census of height and weight for public school students in Arkansas, we find no evidence that changes in fast-food exposure are associated with changes in body mass index z-score for any student subpopulation.

The association between food insecurity and mental health during the COVID-19 pandemic.

OBJECTIVE: To explore the association between food insecurity and mental health outcomes among low-income Americans during the COVID-19 pandemic. METHODS: We conducted a survey of 2714 low-income respondents nationwide from June 29, 2020 to July 21, 2020. A proportional odds logit model was employed to estimate the associations between food insecurity and anxiety and between food insecurity and depression. RESULTS: Food insecurity is associated with a 257% higher risk of anxiety and a 253% higher risk of depression. Losing a job during the pandemic is associated with a 32% increase in risk for anxiety and a 27% increase in risk for depression. CONCLUSIONS: Food insecurity caused by the pandemic was associated with increased risk of mental illness. The relative risk of mental illness from being food insecure is almost three-fold that of losing a job during the pandemic. Public health measures should focus on getting direct subsidies of food purchases to poor families, especially families with children. They should also reduce the stigma and shame that is associated with accepting charitable foods.

Use of Machine Learning to Determine the Information Value of a BMI Screening Program.

INTRODUCTION: Childhood obesity continues to be a significant public health issue in the U.S. and is associated with short- and long-term adverse health outcomes. A number of states have implemented school-based BMI screening programs. However, these programs have been criticized for not being effective in improving students' BMI or reducing childhood obesity. One potential benefit, however, of screening programs is the identification of younger children at risk of obesity as they age. METHODS: This study used a unique panel data set from the BMI screening program for public school children in the state of Arkansas collected from 2003 to 2004 through the 2018-2019 academic years and analyzed in 2020. Machine learning algorithms were applied to understand the informational value of BMI screening. Specifically, this study evaluated the importance of BMI information during kindergarten to the accurate prediction of childhood obesity by the 4th grade. RESULTS: Kindergarten BMI z-score is the most important predictor of obesity by the 4th grade and is much more important to prediction than sociodemographic and socioeconomic variables that would otherwise be available to policymakers in the absence of the screening program. Including the kindergarten BMI z-score of students in the model meaningfully increases the accuracy of the prediction. CONCLUSIONS: Data from the Arkansas BMI screening program greatly improve the ability to identify children at greatest risk of future obesity to the extent that better prediction can be translated into more effective policy and better health outcomes. This is a heretofore unexamined benefit of school-based BMI screening.

Agent-based modeling insights into the optimal distribution of the Fresh Fruit and Vegetable Program.

The Fresh Fruit and Vegetable Program (FFVP) program provides a free fresh fruit or vegetable snack to children in low-income schools between two and five times a week. This is an important nationwide program, but current funding levels are insufficient to reach all eligible schools. Thus, there is a need to develop insight on contextual factors that may impact the effectiveness of FFVP in facilitating the development of childhood food preferences. An agent-based model of preference formation is used to understand how exposure to FFVP in early elementary school may affect preferences for healthy food by 6th grade. Preferences are modeled using the temporal difference learning algorithm used by Hammond et al. (2012). This model simulates habit formation in the context of food by modeling preference formation in terms of positive or negative feedback about the food most recently consumed. The model is designed to provide insights into how different patterns of exposure to FFVP affect preferences, and how living in a food desert changes the effect of FFVP. We use data on 35,981 students from Arkansas elementary schools (from 2008 to 2016) and information about the commercial food environment in Arkansas communities to populate the model. We find that early FFVP exposure is more beneficial than late exposure conditional on the number of years exposed. We also find that FFVP is more beneficial for children who grow up in environments lacking healthy food.

MOVE MORE, GAIN LESS: EFFECT OF A RECREATIONAL TRAIL SYSTEM ON CHILDHOOD BMI.

We investigate the effect of residential proximity to recreational trails on childhood body mass index (BMI). We find that children living within 0.5 miles of recreational trails have BMI z-scores that are 0.0412 to 0.0507 standard deviations lower than those who do not live within 0.5 miles of trails. We also find that living nearby trails reduces the probability of becoming obese by 1.6 percentage points. The impact for BMI z-score is larger for children qualifying for free or reduced-price meals and for Hispanic children. These findings suggest that improving neighborhood amenities conducive to physical activity may help reduce disparities in childhood obesity. (JEL I10, R10).

Do fast food restaurants surrounding schools affect childhood obesity?

In this study, we estimate the effect of fast food environment surrounding schools on childhood body mass index (BMI). We use two methods that arrive at a similar conclusion, but with different implications. Using school distance from the nearest federal highway to instrument for restaurant location, we find the surrounding restaurants to only marginally affect a student's BMI measure. The effect size also decreases with increasing radial distances from school, 0.016 standard deviations at one-third of a mile and 0.0032 standard deviations at a mile radial distance. This indicates the decreasing influence of restaurants on a child's BMI as its distance from school increases. On a subset of students who were exogenously assigned to different school food environment, we find no effect of the fast food restaurants. An important contextual aspect is that nearly all schools in this sample observed closed campus policy, which does not allow students to leave campus during lunch hours.

Supermarket access and childhood bodyweight: Evidence from store openings and closings.

Retail food environment is increasingly considered in relation to obesity. This study investigates the impacts of access to supermarkets, the primary source of healthy foods in the United States, on the bodyweight of children. Empirical analysis uses individual-level panel data covering health screenings of public schoolchildren from Arkansas with annual georeferenced business lists, and utilizes the variations of supermarket openings and closings. There is little overall impact in either case. However, supermarket openings are found to reduce the BMI z-scores of low-income children by 0.090 to 0.096 standard deviations. Such impact remains in a variety of robustness exercises. Therefore, improvement in healthy food access could at least help reduce childhood obesity rates among certain population groups.

Association of Neighborhood Geographic Spatial Factors With Rates of Childhood Obesity.

Importance: Childhood obesity is a principal public health concern. Understanding the geographic distribution of childhood obesity can inform the design and delivery of interventions. Objective: To better understand the causes of spatial dependence in rates of childhood obesity across neighborhoods. Design, Setting, and Participants: This cohort study used data from a legislatively mandated body mass index screening program for public school children in Arkansas from the 2003-2004 through 2014-2015 academic years. Spatial autoregressive moving average (SARMA) models for panel data were used to estimate spatial dependency in childhood obesity at 2 levels of spatial aggregation. Data were analyzed from August 2017 to February 2018. Exposures: The SARMA models included geographic fixed effects to capture time-invariant differences in neighborhood characteristics along with controls for the mean age of children and the proportion of children by race/ethnicity, school meal status, and sex. Main Outcomes and Measures: The proportion of obese schoolchildren in Arkansas neighborhoods by year, defined at larger (census tract) and smaller (census block group) spatial scales. Results: The geographic aggregations were based on 935 800 children with a mean (SD) age of 132 (39) months. Of these children, 51% were male; 65% were white, 21% were black, 10% were Hispanic, 2% were Asian, and the remainder were of other or unidentified race/ethnicity. In models without geographic fixed effects, there was evidence of positive and significant spatial autocorrelation in obesity rates across tracts (ρ = 0.511; 95% CI, 0.469-0.553) and block groups (ρ = 0.569; 95% CI, 0.543-0.595). When geographic fixed effects were included, spatial autocorrelation diminished at the census tract level (ρ = 0.271; 95% CI, 0.147-0.396) and disappeared at the census block group level (ρ = -0.075; 95% CI, -0.264 to 0.114). Conclusions and Relevance: Because block groups are smaller than tracts, children in neighboring block groups were more likely to attend the same schools and interact through neighborhood play. Thus, geographic-based social networks were more likely to span block group boundaries. The lack of evidence of spatial autocorrelation in block group-level models suggests that social contagion may be less important than differences in neighborhood context across space. Caution should be used in interpreting significant spatial autocorrelation as evidence of social contagion in obesity.

Obese Peers' Influence on Students' BMI: Heterogeneity in Race and Sex.

OBJECTIVES: In this study, we investigate peer influence on obesity, with a focus on race and sex. METHODS: We conducted econometric analysis of longitudinal health data of 277,566 public school students, ages 5-13 years. RESULTS: A percentage point increase in the proportion of obese students within the same grade increased a student's BMI z-scores by about 4 one-thousandths of a standard deviation. On racial peers, the standard deviation increase in BMI z-score is 3.9 one-thousandths for Hispanics or Caucasians and 4.9 one-thousandths for African Americans. Influence of obese peers is nearly identical for boys and girls. CONCLUSIONS: Such a small magnitude of obese peers' estimate suggests that classroom peers do not play a substantial role in weight gain or loss in elementary schools.

Persistent disparities in obesity risk among public schoolchildren from childhood through adolescence.

INTRODUCTION: Arkansas is among the poorest states and has high rates of childhood obesity. In 2003, it became the first state to systematically screen public schoolchildren for unhealthy weight status. This study aims to examine the socioeconomic disparities in Body Mass Index (BMI) growth and the risk of the onset of obesity from childhood through adolescence. METHODS: This study analyzed (in 2015) the data for a large cohort of Arkansas public schoolchildren for whom BMIs were measured from school years 2003/2004 through 2009/2010. A linear growth curve model was used to assess how child-level sociodemographics and neighborhood characteristics were associated with growth in BMI z-scores. Cox regression was subsequently used to investigate how these factors were associated with the onset of obesity. Because children might be classified as obese in multiple years, sensitivity analysis was conducted using recurrent event Cox regression. RESULTS: Survival analysis indicated that the risk of onset of obesity rose sharply between ages of 5 and 10 and then again after age 15. The socioeconomic disparities in obesity risk persisted from kindergarten through adolescence. While better access to full service restaurants was associated with lower risk of the onset of obesity (Hazard Ratio (HR)=0.98, 95% CI=0.97-0.99), proximity to fast food restaurants was related to increased risk of the onset of obesity (HR=1.01, 95% CI=1.00-1.01). CONCLUSIONS: This analysis stresses the need for policies to narrow the socioeconomic gradient and identifies important time periods for preventative interventions in childhood obesity.

Middle school transition and body weight outcomes: Evidence from Arkansas Public Schoolchildren.

There is evidence that middle school transition adversely affects educational and psychological outcomes of pre-teen children, but little is known about the impacts of middle school transition on other aspects of health. In this article, we estimate the impact of middle school transition on the body mass index (BMI) of public schoolchildren in Arkansas, United States. Using an instrumental variable approach, we find that middle school transition in grade 6 led to a moderate decrease of 0.04 standard deviations in BMI z-scores for all students. Analysis by subsample indicated that this result was driven by boys (0.06-0.07 standard deviations) and especially by non-minority boys (0.09 standard deviations). We speculate that the changing levels of physical activities associated with middle school transition provide the most reasonable explanation for this result.

Food environment and childhood obesity: the effect of dollar stores.

In this paper we examine the effect of dollar stores on children's Body Mass Index (BMI). We use a dataset compiled by the Arkansas Center for Health Improvement that reflects a BMI screening program for public school children in the state of Arkansas. We combine propensity score matching with difference-in-differences methods to deal with time-invariant as well time-varying unobserved factors. We find no evidence that the presence of dollar stores within a reasonably close proximity of the child's residence increases BMI. In fact, we see an increase in BMI when dollar stores leave a child's neighborhood. Given the proliferation of dollar stores in rural and low-income urban areas, the question of whether dollar stores are contributing to high rates of childhood obesity is policy relevant. However, our results provide some evidence that exposure to dollar stores is not a causal factor.

The effect of fast-food restaurants on childhood obesity: a school level analysis.

We analyze, using an instrumental variable approach, the effect of the number of fast-food restaurants on school level obesity rates in Arkansas. Using distance to the nearest major highway as an instrument, our results suggest that exposure to fast-food restaurants can impact weight outcomes. Specifically, we find that the number of fast-food restaurants within a mile from the school can significantly affect school level obesity rates.