Understanding food insecurity in Los Angeles County during the COVID-19 pandemic and its aftermath: A qualitative interview study

The COVID-19 pandemic brought increases in food insecurity in Los Angeles (L.A.) County, defined as lacking household access to adequate food because of limited money or other resources. Here, we aimed to understand the lived experiences of food insecurity during the COVID-19 pandemic and its aftermath. In August-December 2022, we interviewed 30 residents of L.A. County who were participants in an ongoing internet panel and had reported experiencing food insecurity between April 2020 and July 2021. A stratified-sampling approach was used to recruit a diverse sample with and without government food assistance. We report five key findings, which underscore the stress and worry associated with the experience of food insecurity, and the coping strategies people implemented: (1) The pandemic prompted food insecurity as well as stressful shifts in eating behaviors compared to before the pandemic, with some eating much less food, some eating less nutritious food, and some eating much more due to being stuck at home; (2) Buying food became more effortful and financially challenging; (3) Government food assistance from the Supplemental Nutrition Assistance Program (SNAP) was important for reducing food insecurity, but was sometimes insufficient, inconsistent, and didn't cover all retailers or food items; (4) Interviewees had to rely on their social networks, food banks or pantries, churches, and schools to meet their food needs and cope with food insecurity, but some faced barriers in doing so; (5) For some, food insecurity was worse in late 2022, almost two years after the pandemic started. We conclude with implications for policymakers and practitioners, emphasizing the importance of meeting the needs of diverse residents and addressing food insecurity in the aftermath of the COVID-19 pandemic.

Socio-ecological factors linked with changes in adults' dietary intake in Los Angeles County during the peak of the coronavirus 2019 pandemic

OBJECTIVE

Comprehensive studies examining longitudinal predictors of dietary change during the coronavirus disease 2019 pandemic are lacking. Based on an ecological framework, this study used longitudinal data to test if individual, social and environmental factors predicted change in dietary intake during the peak of the coronavirus 2019 pandemic in Los Angeles County and examined interactions among the multilevel predictors.

DESIGN

We analysed two survey waves (e.g. baseline and follow-up) of the Understanding America Study, administered online to the same participants 3 months apart. The surveys assessed dietary intake and individual, social, and neighbourhood factors potentially associated with diet. Lagged multilevel regression models were used to predict change from baseline to follow-up in daily servings of fruits, vegetables and sugar-sweetened beverages.

SETTING

Data were collected in October 2020 and January 2021, during the peak of the coronavirus disease 2019 pandemic in Los Angeles County.

PARTICIPANTS

903 adults representative of Los Angeles County households.

RESULTS

Individuals who had depression and less education or who identified as non-Hispanic Black or Hispanic reported unhealthy dietary changes over the study period. Individuals with smaller social networks, especially low-income individuals with smaller networks, also reported unhealthy dietary changes. After accounting for individual and social factors, neighbourhood factors were generally not associated with dietary change.

CONCLUSIONS

Given poor diets are a leading cause of death in the USA, addressing ecological risk factors that put some segments of the community at risk for unhealthy dietary changes during a crisis should be a priority for health interventions and policy.

New insights into grocery store visits among east Los Angeles residents using mobility data

In this study, we employed spatially aggregated population mobility data, generated from mobile phone locations in 2021, to investigate patterns of grocery store visits among residents east and northeast of Downtown Los Angeles, in which 60% of the census tracts had previously been designated as "food deserts". Further, we examined whether the store visits varied with neighborhood sociodemographics and grocery store accessibility. We found that residents averaged 0.4 trips to grocery stores per week, with only 13% of these visits within home census tracts, and 40% within home and neighboring census tracts. The mean distance from home to grocery stores was 2.2 miles. We found that people visited grocery stores more frequently when they lived in neighborhoods with higher percentages of Hispanics/Latinos, renters and foreign-born residents, and a greater number of grocery stores. This research highlights the utility of mobility data in elucidating grocery store use, and factors that may facilitate or be a barrier to store access. The results point to limitations of using geographically constrained metrics of food access like food deserts.

Effect of mobile food environments on fast food visits

Poor diets are a leading cause of morbidity and mortality. Exposure to low-quality food environments saturated with fast food outlets is hypothesized to negatively impact diet. However, food environment research has predominantly focused on static food environments around home neighborhoods and generated mixed findings. In this work, we leverage population-scale mobility data in the U.S. to examine 62M people's visits to food outlets and evaluate how food choice is influenced by the food environments people are exposed to as they move through their daily routines. We find that a 10% increase in exposure to fast food outlets in mobile environments increases individuals' odds of visitation by 20%. Using our results, we simulate multiple policy strategies for intervening on food environments to reduce fast-food outlet visits. This analysis suggests that optimal interventions are informed by spatial, temporal, and behavioral features and could have 2x to 4x larger effect than traditional interventions focused on home food environments.

Vulnerability or Resiliency? A Two-Wave Panel Analysis of Social Network Factors Associated with Glycemic Levels among Mexican Immigrants in the Bronx, NYC, Before and During COVID-19

Latinos have high rates of type 2 diabetes mellitus (T2DM) yet are characterized as having health-promoting social networks. The impacts of COVID-19 on personal networks were complex, especially in urban areas with high proportion of immigrants such as the Bronx in NYC. Our objective was to test the extent to which network characteristics increase vulnerability or resiliency for glycemic control based on data gathered from Mexican-origin Bronx dwellers. We used two-wave panel study analyzing self-reported personal social networks (n=30participants; 600network members) and HbA1c levels via dried blood spots in 2019, before the COVID-19 pandemic, and in 2021, a time after initial lockdowns and when the pandemic was still ravaging the community of study. Regression models adjusted for individual-level variables including sociodemographic and health indicators (i.e., physical health including COVID-19 and mental health). We found that an increase in the proportion of network members with diabetes predicted an increase in participant's HbA1c levels from 2019 to 2021 (β=0.044, p < 0.05). Also, a greater proportion of network members consuming "an American diet" in 2019 predicted a decrease in participant's HbA1c levels (β=-0.028, p < 0.01), while a greater proportion of network members that encouraged participants' health in 2019 predicted an increase in participant's HbA1c levels (β=0.033, p < 0.05). Our study sheds light on specific social network characteristics relevant to individual diabetes outcomes, including potential longitudinal mechanistic effects that played out at the peak of the COVID-19 crisis.

Population mobility data provides meaningful indicators of fast food intake and diet-related diseases in diverse populations

The characteristics of food environments people are exposed to, such as the density of fast food (FF) outlets, can impact their diet and risk for diet-related chronic disease. Previous studies examining the relationship between food environments and nutritional health have produced mixed findings, potentially due to the predominant focus on static food environments around people's homes. As smartphone ownership increases, large-scale data on human mobility (i.e., smartphone geolocations) represents a promising resource for studying dynamic food environments that people have access to and visit as they move throughout their day. This study investigates whether mobility data provides meaningful indicators of diet, measured as FF intake, and diet-related disease, evaluating its usefulness for food environment research. Using a mobility dataset consisting of 14.5 million visits to geolocated food outlets in Los Angeles County (LAC) across a representative sample of 243,644 anonymous and opted-in adult smartphone users in LAC, we construct measures of visits to FF outlets aggregated over users living in neighborhood. We find that the aggregated measures strongly and significantly correspond to self-reported FF intake, obesity, and diabetes in a diverse, representative sample of 8,036 LAC adults included in a population health survey carried out by the LAC Department of Public Health. Visits to FF outlets were a better predictor of individuals' obesity and diabetes than their self-reported FF intake, controlling for other known risks. These findings suggest mobility data represents a valid tool to study people's use of dynamic food environments and links to diet and health.

Ecological risk and protective factors for food insufficiency in Los Angeles County during the COVID-19 pandemic

OBJECTIVE

The COVID-19 pandemic increased food insufficiency: a severe form of food insecurity. Drawing on an ecological framework, we aimed to understand factors that contributed to changes in food insufficiency from April to December 2020, in a large urban population hard hit by the pandemic.

DESIGN

We conducted internet surveys every 2 weeks in April-December 2020, including a subset of items from the Food Insecurity Experience Scale. Longitudinal analysis identified predictors of food insufficiency, using fixed effects models.

SETTING

Los Angeles County, which has a diverse population of 10 million residents.

PARTICIPANTS

A representative sample of 1535 adults in Los Angeles County who are participants in the Understanding Coronavirus in America tracking survey.

RESULTS

Rates of food insufficiency spiked in the first year of the pandemic, especially among participants living in poverty, in middle adulthood and with larger households. Government food assistance from the Supplemental Nutrition Assistance Program was significantly associated with reduced food insufficiency over time, while other forms of assistance such as help from family and friends or stimulus funds were not.

CONCLUSIONS

The findings highlight that during a crisis, there is value in rapidly monitoring food insufficiency and investing in government food benefits.

Food Insecurity Is Under-reported in Surveys That Ask About the Past Year

INTRODUCTION

Food insecurity affects one in ten Americans in a typical year; recent U.S. Department of Agriculture data show that this food insecurity rate was stable from 2019 to 2021. However, data from Los Angeles County and other U.S. regions show that food insecurity spiked during the early months of the COVID-19 pandemic. One reason for this discrepancy may be that food insecurity measures assess experiences over different time frames. This study investigated the discrepancies in food insecurity rates by comparing past-week and past-year food insecurity measures and explored the role of recall bias.

METHODS

Data were obtained from a representative survey panel of Los Angeles adults (N=1,135). Participants were surveyed about past-week food insecurity eleven times throughout 2021 and once about past-year food insecurity in December 2021. Data were analyzed in 2022.

RESULTS

Of the participants who reported past-week food insecurity at any time in 2021, only two thirds also reported past-year food insecurity in December 2021, suggesting that one third of participants under-reported past-year food insecurity. Logistic regression models indicated that three characteristics were significantly associated with under-reporting of past-year food insecurity: having reported past-week food insecurity at fewer survey waves, not reporting recent past-week food insecurity, and having a relatively high household income.

CONCLUSIONS

These results suggest substantial under-reporting of past-year food insecurity, related to recall bias and social factors. Measuring food insecurity at multiple points throughout the year may help to improve the accuracy of reporting and public health surveillance of this issue.

Nosotros mismos nos estamos matando/We are the ones killing ourselves: Unraveling individual and network characteristics associated with negative dietary acculturation among Mexican Americans in New York City

BACKGROUND

Research on negative dietary acculturation among Mexican-Americans has mostly focused on individual-level processes and has largely ignored the role of social networks.

METHODS

This mixed-method study used an egocentric network approach and derived 1620 personal ties of self-identified Mexican adults in New York. 24-hour dietary recalls were used to derive a total Healthy Eating Index (HEI) and subscores. The qualitative portion generated narratives around who helps or hinders their efforts to eat healthfully.

RESULTS

At the individual level, age at which participants migrated to the U.S. was negatively associated with total HEI (β = -0.39, p < .01). An annual income below $30,000 was positively associated with total HEI (β = 0.25, p < .05) and with HEI fruit subscores (β = 0.25, p < .05). Acculturative stress was negatively associated with HEI fruit (β = -0.29, p < .05) and refined grain subscores (β = -0.34, p < .01). At the network level, the proportion of network members who consumed traditional Latino diets was negatively associated with total HEI and HEI refined grains subscores (β = -0.39, p < .001; and β = -0.23, p < .05; respectively). In contrast, the proportion of alters who lived in another country was positively associated with HEI dairy subscores (β = 0.25, p < .05). Juxtaposing qualitative participants' visual representation of their total HEI scores with their lay interpretations of healthy and unhealthy eating matched public health messages of reducing sugar, red meat intake, and processed foods. However, participants felt that this could only be achieved through restriction rather than balance. Qualitative narratives also elucidated how dietary acculturation and income could help shape dietary quality in unexpected ways.

CONCLUSIONS

This study found evidence of negative dietary acculturation and showcases the complex ways in which both individual- and network-level processes help shape dietary choices for Mexican-Americans.

Perceptions of social circle vaccine acceptance and COVID-19 vaccine initiation among postpriority vaccine eligible adults

OBJECTIVES

COVID-19 vaccines in the United States were made available to the general public aged 16 years and older in April 2021, but uptake in the months following was variable. We aimed to investigate this variability as a function of interpersonal factors, namely perceived social circle vaccine acceptance and proximity to illness, controlling for intrapersonal factors more often associated with vaccine behavior.

METHOD

Data come from the Understanding Coronavirus in America tracking survey (February 2021-July 2021). We estimated the probability of vaccination among those who were unvaccinated as of April 14, 2021 (N = 2,199), the day before the announcement of general public eligibility. Stratified modeling by race accounted for subgroup differences.

RESULTS

People who perceived social circle vaccine acceptance (Hazard Ratio [HR] = 1.37, p < .001), higher risk of infection (HR = 1.20, p < .001), greater trust in the vaccine (HR = 1.42, p < .001), and lower risk of vaccine side effects (HR = 0.77, p < .001) were more likely to get vaccinated. Perceptions of social circle vaccine acceptance were associated with vaccine initiation for all racial subgroups except Black respondents, for whom concerns about vaccine side effects were central.

CONCLUSIONS

Perceived social circle vaccine acceptance was associated with time to the first dose of the COVID-19 vaccine. With public uncertainty about this new vaccine, people may have relied on perceptions of peers' vaccination intentions when deciding on their own vaccination. We discuss strategies for promoting vaccine uptake by intervening on perceptions of social norms. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Integration of Time-Based Recommendations with Current Pediatric Health Behavior Guidelines: Implications for Obesity Prevention and Treatment in Youth

PURPOSE OF REVIEW

Youth-onset obesity is associated with negative health outcomes across the lifespan including cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, dyslipidemias, asthma, and several cancers. Pediatric health guidelines have traditionally focused on the quality and quantity of dietary intake, physical activity, and sleep.

RECENT FINDINGS

Emerging evidence suggests that the timing (time of day when behavior occurs) and composition (proportion of time spent allocated to behavior) of food intake, movement (i.e., physical activity, sedentary time), and sleep may independently predict health trajectories and disease risks. Several theoretically driven interventions and conceptual frameworks feature behavior timing and composition (e.g., 24 h movement continuum, circadian science and chronobiology, intermittent fasting regimens, structured day hypothesis). These literatures are, however, disparate, with little crosstalk across disciplines. In this review, we examine dietary, sleep, and movement guidelines and recommendations for youths ages 0-18 in the context of theoretical models and empirical findings in support of time-based approaches. The review aims to inform a unifying framework of health behaviors and guide future research on the integration of time-based recommendations into current quantity and quality-based health guidelines for children and adolescents.

Examining food intake similarities in adolescent best friend dyads using longitudinal Actor-Partner Interdependence Models

Little is known about how adolescent best friends may affect each other's food intake. This study explored whether friendship selection and socialization mechanisms explained potential food intake similarities in adolescent reciprocated best friend dyads. We also tested whether socialization processes were moderated by dyad member's relative zBMI. Members of 145 same-gender best friendship dyads (56% female; Mage = 12.79; SDage = 0.61) reported on their intake of food obtained from home and from outside the home at the beginning and the end of the school year through food frequency questionnaires. Longitudinal Actor-Partner Interdependence Models results showed no indication of selection or socialization, and very limited evidence for the moderation of socialization processes by relative zBMI. These findings indicate that focusing on adolescent reciprocated best friends in dietary interventions may not be valuable.

Diet and Physical Activity Behaviors of Families Receiving Maternal and Child Health Services: The Perspective of the Home Visitor

Women and children enrolled in federally funded home visitation services are at an increased risk for unhealthy diet and physical activity patterns. Home visitors have a privileged relationship with their clients and hold a unique perspective of the multilevel influences surrounding these behaviors. This study explored the question: "What are home visitors' perspectives and experiences with their families' diet and physical activity behaviors?" Home visitors enrolled in a larger trial were invited to participate in focus group sessions (n=13). Topics covered their clients' constraints and capacity building opportunities for healthful diet and activity practices. Reflexive thematic analysis was used to analyze the data. The home visitors discussed key influences on diet and activity, and three overarching themes were identified: (a) acute periods of crises and mental health issues; (b) the role of the mother within the family; and (c) support and barriers within mothers' broader social network. The themes identified in this study highlight the complex, multidimensional influences on the dietary and physical activity patterns of these families, and pinpoint key areas of opportunity for intervention.

Validity and Feasibility of the Monitoring and Modeling Family Eating Dynamics System to Automatically Detect In-field Family Eating Behavior: Observational Study

Background

The field of dietary assessment has a long history, marked by both controversies and advances. Emerging technologies may be a potential solution to address the limitations of self-report dietary assessment methods. The Monitoring and Modeling Family Eating Dynamics (M2FED) study uses wrist-worn smartwatches to automatically detect real-time eating activity in the field. The ecological momentary assessment (EMA) methodology was also used to confirm whether eating occurred (ie, ground truth) and to measure other contextual information, including positive and negative affect, hunger, satiety, mindful eating, and social context.

Objective

This study aims to report on participant compliance (feasibility) to the 2 distinct EMA protocols of the M2FED study (hourly time-triggered and eating event–triggered assessments) and on the performance (validity) of the smartwatch algorithm in automatically detecting eating events in a family-based study.

Methods

In all, 20 families (58 participants) participated in the 2-week, observational, M2FED study. All participants wore a smartwatch on their dominant hand and responded to time-triggered and eating event–triggered mobile questionnaires via EMA while at home. Compliance to EMA was calculated overall, for hourly time-triggered mobile questionnaires, and for eating event–triggered mobile questionnaires. The predictors of compliance were determined using a logistic regression model. The number of true and false positive eating events was calculated, as well as the precision of the smartwatch algorithm. The Mann-Whitney U test, Kruskal-Wallis test, and Spearman rank correlation were used to determine whether there were differences in the detection of eating events by participant age, gender, family role, and height.

Results

The overall compliance rate across the 20 deployments was 89.26% (3723/4171) for all EMAs, 89.7% (3328/3710) for time-triggered EMAs, and 85.7% (395/461) for eating event–triggered EMAs. Time of day (afternoon odds ratio [OR] 0.60, 95% CI 0.42-0.85; evening OR 0.53, 95% CI 0.38-0.74) and whether other family members had also answered an EMA (OR 2.07, 95% CI 1.66-2.58) were significant predictors of compliance to time-triggered EMAs. Weekend status (OR 2.40, 95% CI 1.25-4.91) and deployment day (OR 0.92, 95% CI 0.86-0.97) were significant predictors of compliance to eating event–triggered EMAs. Participants confirmed that 76.5% (302/395) of the detected events were true eating events (ie, true positives), and the precision was 0.77. The proportion of correctly detected eating events did not significantly differ by participant age, gender, family role, or height (P>.05).

Conclusions

This study demonstrates that EMA is a feasible tool to collect ground-truth eating activity and thus evaluate the performance of wearable sensors in the field. The combination of a wrist-worn smartwatch to automatically detect eating and a mobile device to capture ground-truth eating activity offers key advantages for the user and makes mobile health technologies more accessible to nonengineering behavioral researchers.

Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity

INTRODUCTION

Behavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of individual and trial-level subgroups. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups.

METHODS AND ANALYSIS

Systematic searches of Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2021 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index z-score at age 24±6 months using WHO Growth Standards, and effect differences will be explored among prespecified individual and trial-level subgroups. Secondary outcomes include other child weight-related measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events.

ETHICS AND DISSEMINATION

Approved by The University of Sydney Human Research Ethics Committee (2020/273) and Flinders University Social and Behavioural Research Ethics Committee (HREC CIA2133-1). Results will be relevant to clinicians, child health services, researchers, policy-makers and families, and will be disseminated via publications, presentations and media releases.

PROSPERO REGISTRATION NUMBER

CRD42020177408.

Unpacking the behavioural components and delivery features of early childhood obesity prevention interventions in the TOPCHILD Collaboration: a systematic review and intervention coding protocol

INTRODUCTION

Little is known about how early (eg, commencing antenatally or in the first 12 months after birth) obesity prevention interventions seek to change behaviour and which components are or are not effective. This study aims to (1) characterise early obesity prevention interventions in terms of target behaviours, delivery features and behaviour change techniques (BCTs), (2) explore similarities and differences in BCTs used to target behaviours and (3) explore effectiveness of intervention components in preventing childhood obesity.

METHODS AND ANALYSIS

Annual comprehensive systematic searches will be performed in Epub Ahead of Print/MEDLINE, Embase, Cochrane (CENTRAL), CINAHL, PsycINFO, as well as clinical trial registries. Eligible randomised controlled trials of behavioural interventions to prevent childhood obesity commencing antenatally or in the first year after birth will be invited to join the Transforming Obesity in CHILDren Collaboration. Standard ontologies will be used to code target behaviours, delivery features and BCTs in both published and unpublished intervention materials provided by trialists. Narrative syntheses will be performed to summarise intervention components and compare applied BCTs by types of target behaviours. Exploratory analyses will be undertaken to assess effectiveness of intervention components.

ETHICS AND DISSEMINATION

The study has been approved by The University of Sydney Human Research Ethics Committee (project no. 2020/273) and Flinders University Social and Behavioural Research Ethics Committee (project no. HREC CIA2133-1). The study's findings will be disseminated through peer-reviewed publications, conference presentations and targeted communication with key stakeholders.

PROSPERO REGISTRATION NUMBER

CRD42020177408.

Formative Evaluation of the Families SHARE Disease Risk Tool among Low-Income African Americans

INTRODUCTION

Family Health Histories (FHH) have been endorsed by the surgeon general as a powerful yet underutilized tool for identifying individuals at risk for complex chronic diseases such as diabetes, heart disease, and cancer. FHH tools provide a mechanism for increasing communication about disease history and motivating behavior change to reduce disease risk. A critical gap in translation efforts includes a lack of research that adapts and evaluates tools for low-income, minority populations who experience disparities in chronic disease.

METHODS

This study is a formative mixed-methods evaluation of an evidence-based FHH intervention called "Families SHARE" among African Americans residing in low-income neighborhoods. Participants (N = 51) completed assessments before and 6 weeks after receiving the intervention, including surveys and focus groups. We evaluated (a) their use, understanding, and perceived value of the tool; (b) if the intervention led to increased intentions to adopt disease risk-reducing behaviors among those with heightened disease risk, given their FHH; and (c) acceptability of and recommendations for the tool.

RESULTS

The quantitative and qualitative data indicated that this population valued and used the tool, and it prompted communication about FHH with family, friends, and others. Receipt of the intervention resulted in mixed accuracy of their perceived disease risk, and it did not shift intentions to change health behaviors. Qualitative data provide insights for future iterations of the Families SHARE tool.

CONCLUSION

Families SHARE is an engaging FHH tool that can be further tailored to optimize its value and benefits for low-income African Americans.

Self-reported dietary changes among Los Angeles County adults during the COVID-19 pandemic

Poor diets are historically the leading cause of morbidity and mortality in the United States (U.S.), causing over 44,000 deaths each month. Dietary patterns have likely changed during the COVID-19 pandemic due to major shifts and crises in social, economic, and food systems. This study examines self-reported dietary changes in Los Angeles (L.A.) County during COVID-19, and identifies factors associated with making healthy and unhealthy changes. Data are from the Understanding Coronavirus in America Study, an internet panel of adults representative of L.A. County households (N = 1080). Multinomial logistic regression was used to test if self-reported change in diet healthiness assessed in July 2020 was associated with socio-ecological factors known to be associated with diet, assessed between April-July 2020. More than half of L.A. County residents reported making changes to their diet: 28.3% reported eating healthier food since the beginning of the pandemic, while 24.8% reported eating less healthy food. Individuals who were significantly more likely to report healthy changes were Non-Hispanic Black or Hispanic/Latino (vs. Non-Hispanic White), had received unemployment insurance, or had larger social networks. Individuals who were significantly more likely to report unhealthy changes were younger, of mixed race, had children in their household, had transportation barriers, or had obesity. Individuals who were significantly more likely to report both healthy and unhealthy changes were Asian, had experienced food insecurity, or had challenges getting food due to store closures. The pandemic may be exacerbating diet-related disease risk in some groups, such as communities of color, and among individuals with obesity and those facing transportation barriers.

Leveraging Emergent Social Networks to Reduce Sedentary Behavior in Low-Income Parents With Preschool-Aged Children

This study tested the hypothesis that parents participating in a pediatric obesity intervention who formed social network ties with a parent in the intervention arm would engage in more daily physical activity and less sedentary behavior (after controlling for participant covariates). Data were collected at baseline, 12 months, and 36 months from 610 low-income parent-child pairs participating in an obesity prevention intervention for 3- to 5-year-old children. A network survey was used to identify social network ties among parents and accelerometers were used to measure parental physical activity and sedentary time. Longitudinal regression analyses tested effects of social network ties on parents' physical activity and sedentary behavior. Compared with parents without a social network tie, having a tie with an intervention group participant was associated with a clinically meaningful 11.04 min/day decrease in parental sedentary behavior that approached statistical significance (95% confidence interval [Cl] = [-22.71, 0.63], p = .06). Social network ties among parents in a pediatric obesity prevention intervention were not clearly associated with reduced sedentary behavior among those parents at the traditional level of p = .05. The large effect size (over 77min per week improvement) suggests there might be potential importance of promoting new social networks in community-based health promotion interventions to elicit and support behavior change, but further examination is needed.

An integrated risk and epidemiological model to estimate risk-stratified COVID-19 outcomes for Los Angeles County: March 1, 2020-March 1, 2021

The objective of this study was to use available data on the prevalence of COVID-19 risk factors in subpopulations and epidemic dynamics at the population level to estimate probabilities of severe illness and the case and infection fatality rates (CFR and IFR) stratified across subgroups representing all combinations of the risk factors age, comorbidities, obesity, and smoking status. We focus on the first year of the epidemic in Los Angeles County (LAC) (March 1, 2020-March 1, 2021), spanning three epidemic waves. A relative risk modeling approach was developed to estimate conditional effects from available marginal data. A dynamic stochastic epidemic model was developed to produce time-varying population estimates of epidemic parameters including the transmission and infection observation rate. The epidemic and risk models were integrated to produce estimates of subpopulation-stratified probabilities of disease progression and CFR and IFR for LAC. The probabilities of disease progression and CFR and IFR were found to vary as extensively between age groups as within age categories combined with the presence of absence of other risk factors, suggesting that it is inappropriate to summarize epidemiological parameters for age categories alone, let alone the entire population. The fine-grained subpopulation-stratified estimates of COVID-19 outcomes produced in this study are useful in understanding disparities in the effect of the epidemic on different groups in LAC, and can inform analyses of targeted subpopulation-level policy interventions.

An action-oriented framework for systems-based solutions aimed at childhood obesity prevention in US Latinx and Latin American populations

Childhood obesity in US Latinx and Latin American populations is a persistent, complex public health issue and, as such, requires solutions grounded on systems science theory and methods. In this paper, we introduce an action-oriented framework to design, implement, evaluate, and sustain whole-of-community systems changes for childhood obesity prevention in US Latinx and Latin American populations. Our framework covers six action steps: (1) foster multisectoral team; (2) map the system, its context, and drivers; (3) envision system-wide changes; (4) effect system-wide changes; (5) monitor, learn, and adapt; and (6) scale and sustain. We also propose 10 principles that put human and environmental rights and systems thinking at the center of these systems-based solutions. For each action step, we provide a list of concrete activities, methods, approaches, and examples that can be used to guide and inform the work needed to achieve the expected outputs. Finally, we discuss how a wider adoption of systems science for childhood obesity prevention among US Latinx and Latin American populations can be encouraged and sustained.

Four-Year Behavioral, Health-Related Quality of Life, and BMI Outcomes from a Cluster Randomized Whole of Systems Trial of Prevention Strategies for Childhood Obesity

OBJECTIVE

This study aimed to test the effectiveness of the Whole of Systems Trial of Prevention Strategies for Childhood Obesity (WHO STOPS Childhood Obesity) for behavioral, health-related quality of life (HRQoL), and BMI outcomes.

METHODS

This was a cluster randomized trial of 10 communities randomly allocated (1:1) to start intervention in 2015 (step 1) or in 2019 (after 4 years) in South West Victoria, Australia. Data were collected from participating primary schools in April to June of 2015 (73% school participation rate), 2017 (69%), and 2019 (63%). Student participation rates were 80% in 2015 (1,792/2,516 invited), 81% in 2017 (2,411/2,963), and 79% in 2019 (2,177/2,720). Repeat cross-sectional analyses of measured height and weight (grades two, four, and six [aged approximately 7 to 12 years]), self-reported behavior, and HRQoL (grades four and six) were conducted.

RESULTS

There was an intervention by time interaction in BMI z scores (P = 0.031) and obesity/overweight prevalence (P = 0.006). BMI z score and overweight/obesity prevalence decreased between 2015 and 2017 and increased between 2017 and 2019 in intervention communities. The intervention significantly reduced takeaway food consumption (P = 0.034) and improved physical (P = 0.019), psychosocial (P = 0.026), and global (P = 0.012) HRQoL. Water consumption increased among girls (P = 0.033) in the intervention communities, as did energy-dense, nutrient-poor snack consumption among boys (P = 0.006).

CONCLUSIONS

WHO STOPS had a positive impact on takeaway food intake and HRQoL.

Estimation of COVID-19 risk-stratified epidemiological parameters and policy implications for Los Angeles County through an integrated risk and stochastic epidemiological model

Background

Health disparities have emerged with the COVID-19 epidemic because the risk of exposure to infection and the prevalence of risk factors for severe outcomes given infection vary within and between populations. However, estimated epidemic quantities such as rates of severe illness and death, the case fatality rate (CFR), and infection fatality rate (IFR), are often expressed in terms of aggregated population-level estimates due to the lack of epidemiological data at the refined subpopulation level. For public health policy makers to better address the pandemic, stratified estimates are necessary to investigate the potential outcomes of policy scenarios targeting specific subpopulations.

Methods

We develop a framework for using available data on the prevalence of COVID-19 risk factors (age, comorbidities, BMI, smoking status) in subpopulations, and epidemic dynamics at the population level and stratified by age, to estimate subpopulation-stratified probabilities of severe illness and the CFR (as deaths over observed infections) and IFR (as deaths over estimated total infections) across risk profiles representing all combinations of risk factors including age, comorbidities, obesity class, and smoking status. A dynamic epidemic model is integrated with a relative risk model to produce time-varying subpopulation-stratified estimates. The integrated model is used to analyze dynamic outcomes and parameters by population and subpopulation, and to simulate alternate policy scenarios that protect specific at-risk subpopulations or modify the population-wide transmission rate. The model is calibrated to data from the Los Angeles County population during the period March 1 - October 15 2020.

Findings

We estimate a rate of 0.23 (95% CI: 0.13,0.33) of infections observed before April 15, which increased over the epidemic course to 0.41 (0.11,0.69). Overall population-average IFR( t ) estimates for LAC peaked at 0.77% (0.38%,1.15%) on May 15 and decreased to 0.55% (0.24%,0.90%) by October 15. The population-average IFR( t ) stratified by age group varied extensively across subprofiles representing each combination of the additional risk factors considered (comorbidities, BMI, smoking). We found median IFRs ranging from 0.009%-0.04% in the youngest age group (0-19), from 0.1%-1.8% for those aged 20-44, 0.36%-4.3% for those aged 45-64, and 1.02%-5.42% for those aged 65+. In the group aged 65+ for which the rate of unobserved infections is likely much lower, we find median CFRs in the range 4.4%-23.45%. The initial societal lockdown period avoided overwhelming healthcare capacity and greatly reduced the observed death count. In comparative scenario analysis, alternative policies in which the population-wide transmission rate is reduced to a moderate and sustainable level of non-pharmaceutical interventions (NPIs) would not have been sufficient to avoid overwhelming healthcare capacity, and additionally would have exceeded the observed death count. Combining the moderate NPI policy with stringent protection of the at-risk subpopulation of individuals 65+ would have resulted in a death count similar to observed levels, but hospital counts would have approached capacity limits.

Interpretation

The risk of severe illness and death of COVID-19 varies tremendously across subpopulations and over time, suggesting that it is inappropriate to summarize epidemiological parameters for the entire population and epidemic time period. This includes variation not only across age groups, but also within age categories combined with other risk factors analyzed in this study (comorbidities, obesity status, smoking). In the policy analysis accounting for differences in IFR across risk groups in comparing the control of infections and protection of higher risk groups, we find that the strict initial lockdown period in LAC was effective because it both reduced overall transmission and protected individuals at greater risk, resulting in preventing both healthcare overload and deaths. While similar numbers of deaths as observed in LAC could have been achieved with a more moderate NPI policy combined with greater protection of individuals 65+, this would have come at the expense of overwhelming the healthcare system. In anticipation of a continued rise in cases in LAC this winter, policy makers need to consider the trade offs of various policy options on the numbers of the overall population that may become infected, severely ill, and that die when considering policies targeted at subpopulations at greatest risk of transmitting infection and at greatest risk for developing severe outcomes.

Abstract IA15: Mobile virtual human health care guides for young adult childhood cancer survivors

Since the mid-1990s, a significant scientific literature has evolved regarding the mental/physical health outcomes from the use of what we now refer to as Clinical Virtual Reality (VR). While the preponderance of clinical work with VR has focused on building immersive virtual worlds for treating anxiety disorders with exposure therapy, providing distracting immersive experiences for acute pain management, and supporting physical rehabilitation with game-based interactive content, there are other emerging areas that have extended the impact of VR in healthcare. One such area involves the recent technological advances that have led to the evolution of intelligent virtual human (VH) agents. VH representations can now be designed to perceive and act in a 3D virtual world, engage in face-to-face spoken dialogues with real users, and in some cases, can exhibit human-like emotional reactions. We have reported positive outcomes from studies using VHs in the role of virtual patients for training novice clinicians, as job interview/social skill trainers for persons on the autism spectrum, and as online health care support agents with university students and military veterans. The computational capacity now exists to deliver similar VH interactions by way of mobile device technology. This capability can support the “anywhere/anytime” availability of VH characters as agents for engaging users with clinical care information and could provide opportunities for improving access to care and emotional support for childhood cancer survivors (CCS). With a survivorship rate of over 83%, CCS are living longer, with estimates indicating that there will be over 500,000 CCS in the United States by 2020. However, CCS are at high risk for late effects of treatment, including recurring or secondary cancers, unhealthy lifestyle, disengagement from care, and the lack of the social support that has been shown to be vital for health and well-being. The majority of CCS will have at least one chronic condition by age 40. Moreover, existing initiatives to serve the needs of CCS have had limited success as these populations can be hard to reach and difficult to engage. We conducted two preliminary studies to inform development and evaluate the usefulness of a mobile app that included VH interaction and guidance to help CCS navigate survivorship and maintain health. In Study 1, two rounds of focus group interviews were conducted with 15 CCS aged 13-30 years. In Study 2, a pilot VH-driven app was developed using the information collected in Study 1. The app was downloaded, tested, and evaluated for one week by 60 CCS between the ages of 13-29 years. The results indicated that dynamic, accessible, engaging and survivor-focused VH approaches could address the needs of young, “digitally native” CCS. We will present a brief introduction to the clinical use of VHs within the VR context (Rizzo), followed by a discussion of a new mobile-enabled VH project designed to promote access to health care information and emotional support in young adult CCS (Spruijt-Metz).

Citation Format: Skip Rizzo, Donna Spruijt-Metz, Arno Hartholt, Bill Swartout, Kayla de la Haye, Joel Milam, David Freyer, Kimberly Miller, Anamara Ritt-Olson, Stacy Schepens-Niemiec, Shinyi Wu, Maryalice Jordan-Marsh, Amie Hwang, Anya Samek, Dennis Wixon, George Tolomiczenko, Kenneth Hayashida, Marientina Gotsis, Stefan Schneider, Swaroop Samek, Yaniv Bar-Cohen. Mobile virtual human health care guides for young adult childhood cancer survivors [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr IA15.

Identifying Social Network Conditions that Facilitate Sedentary Behavior Change: The Benefit of Being a "Bridge" in a Group-based Intervention

Using data from one of the first trials to try to leverage social networks as a mechanism for obesity intervention, we examined which social network conditions amplified behavior change. Data were collected as part of a community-based healthy lifestyle intervention in Nashville, USA, between June 2014 and July 2017. Adults randomized to the intervention arm were assigned to a small group of 10 participants that met in person for 12 weekly sessions. Intervention small group social networks were measured three times; sedentary behavior was measured by accelerometry at baseline and 12 months. Multivariate hidden Markov models classified people into distinct social network trajectories over time, based on the structure of the emergent network and where the individual was embedded. A multilevel regression analysis assessed the relationship between network trajectory and sedentary behavior (N = 261). Being a person that connected clusters of intervention participants at any point during the intervention predicted an average reduction of 31.3 min/day of sedentary behavior at 12 months, versus being isolated [95% CI: (−61.4, −1.07), p = 0.04]. Certain social network conditions may make it easier to reduce adult sedentary behavior in group-based interventions. While further research will be necessary to establish causality, the implications for intervention design are discussed.

Automatic, wearable-based, in-field eating detection approaches for public health research: a scoping review

Dietary intake, eating behaviors, and context are important in chronic disease development, yet our ability to accurately assess these in research settings can be limited by biased traditional self-reporting tools. Objective measurement tools, specifically, wearable sensors, present the opportunity to minimize the major limitations of self-reported eating measures by generating supplementary sensor data that can improve the validity of self-report data in naturalistic settings. This scoping review summarizes the current use of wearable devices/sensors that automatically detect eating-related activity in naturalistic research settings. Five databases were searched in December 2019, and 618 records were retrieved from the literature search. This scoping review included N = 40 studies (from 33 articles) that reported on one or more wearable sensors used to automatically detect eating activity in the field. The majority of studies (N = 26, 65%) used multi-sensor systems (incorporating > 1 wearable sensors), and accelerometers were the most commonly utilized sensor (N = 25, 62.5%). All studies (N = 40, 100.0%) used either self-report or objective ground-truth methods to validate the inferred eating activity detected by the sensor(s). The most frequently reported evaluation metrics were Accuracy (N = 12) and F1-score (N = 10). This scoping review highlights the current state of wearable sensors' ability to improve upon traditional eating assessment methods by passively detecting eating activity in naturalistic settings, over long periods of time, and with minimal user interaction. A key challenge in this field, wide variation in eating outcome measures and evaluation metrics, demonstrates the need for the development of a standardized form of comparability among sensors/multi-sensor systems and multidisciplinary collaboration.

Intergenerational exchange of healthful eating encouragement: Consideration of family ancestry and disease history

INTRODUCTION

Improving diet is a prime target for the prevention and management of chronic disease. The communal coping model suggests that families can mitigate shared risk of chronic disease through encouragement of healthful eating, eliciting preventive behaviors.

METHOD

Using network data from 69 Australian families across three ancestry groups (Anglo, Italian, and Asian) with varied family health histories, the present study applied social network analysis to identify patterns of intergenerational encouragement of healthful eating behavior within families, and assess whether patterns varied by family ancestry or disease density.

RESULTS

Findings indicated variation in patterns of health encouragement by ancestry such that Asian-Australian families were most distinct from the other ancestry groups. While there was no main effect of familial disease history, it moderated the effect of Italian ancestry on intergenerational encouragement patterns.

DISCUSSION

These results provide important context for future family based interventions that leverage normative patterns of intergenerational exchange of encouragement or aim to modify such patterns in an effort to improve family health. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Smoking Diffusion through Networks of Diverse, Urban American Adolescents over the High School Period

This study uses recent data to investigate if smoking initiation diffuses through friendship networks over the high school period and explores if diffusion processes differ across schools. One thousand four hundred and twenty-five racially and ethnically diverse youth from four high schools in Los Angeles were surveyed four times over the high school period from 2010 to 2013. Probit regression models and stochastic actor-based models for network dynamics tested for peer effects on smoking initiation. Friend smoking was found to predict adolescent smoking, and smoking initiation diffused through friendship networks in some but not all of the schools. School differences in smoking rates and the popularity of smokers may be linked to differences in the diffusion of smoking through peer networks. We conclude that there are differences in peer effects on smoking initiation across schools that will be important to account for in network-based smoking interventions.

Personal Network Characteristics as Predictors of Change in Obesity Risk Behaviors in Early Adolescence

The potential for peers to influence obesity risk behavior increases in adolescence, yet there are knowledge gaps of how behaviors are modified in response to peers over time. This study examined how personal friendship network characteristics were associated with obesity-related behaviors from late childhood to early adolescence. Two waves of friendship, physical activity, screen time, and dietary recall data were collected from 11- to 13-year-old students (99% retention) in Australia (n = 308) over a five- to eight-month period. Regression models identified friendship network characteristics that predicted later health behaviors which varied by gender and behavior type, such as the number of friends positively associated with physical activity intensity (males) and screen time (females). The need for considering context to influence behavior change is discussed.

The role of maternal social networks on the outcomes of a home-based childhood obesity prevention pilot intervention

BACKGROUND

Despite evidence that obesity and related behaviors are influenced by social networks and social systems, few childhood obesity initiatives have focused on social network factors as moderators of intervention outcomes, or targets for intervention strategies.

OBJECTIVES

This pilot study examines associations between maternal social network characteristics hypothesized to influence health behaviors, and the target outcomes of a family-centered childhood obesity prevention initiative. The pilot intervention entailed the provision of healthy eating and activity components as part of an existing home visiting program (HVP) delivered to mothers and infants, to test the feasibility of this approach for improving mother diet, physical activity, and weight status; and infant diet and weight trajectory.

METHODS

Mothers and their infants (N=50 dyads) receiving services from our HVP partner were recruited and randomized to receive the HVP core curriculum with or without a nutrition and physical activity enhancement module for six months. Assessments of mothers' social network characteristics, mother/infant food intake and mother physical activity, and mothers' postpartum weight retention and children's growth velocity were conducted at baseline and post-intervention.

RESULTS

Several features of mothers' social networks, including the receipt of health-related social support, were significantly associated with the focal intervention outcomes (p < .05) at follow-up, controlling for study condition.

CONCLUSIONS

Integrating childhood obesity prevention into HVPs appears promising. Future family-based interventions to prevent childhood obesity may be enhanced by including social network intervention strategies. For example, by addressing family network characteristics that impede healthy behavior change, or enhancing networks by fostering social support for healthy behavior and weight change.

In-home obesity prevention in low-income infants through maternal and social transmission

BACKGROUND

Extant obesity efforts have had a limited impact among low-income underserved children, in part because existing programs are limited in terms of their short duration and low dosage, limited accessibility and sustainability; and failure to address barriers faced by diverse low-income families.

METHODS

This two-arm, parallel, randomized controlled trial (RCT) tests whether delivering obesity prevention, as part of an ongoing home visitation program (HVP), is an effective approach for primary (infants) and secondary (mothers) obesity prevention among low-income, underserved families. This RCT further examines the role of maternal and social factors as key mechanisms of transmission of infants' obesity risk, and the real-life costs of delivering obesity prevention as part of HVPs. Specifically, 300 low-income mothers/infants (6mo at baseline) participating in the Healthy Families America home visitation program in Antelope Valley (CA) will be recruited and enrolled in the study. Home visitors serving families will be randomly assigned to deliver the standard HVP curriculum with or without obesity prevention as part of their weekly home visits for two years. Anthropometric, metabolic and behavioral assessments of mothers/infants will be conducted at enrollment and after 6 and 18 months of intervention.

DISCUSSION

This study addresses the need to develop interventions targeting at-risk infants before they become obese. The proposed research is timely as the Institute of Medicine, the United States Department of Agriculture, and the Department of Health and Human Services are revising their recommendations to address key factors influencing obesity risk in children from birth to 24 months of age.

Adolescent peer networks and the moderating role of depressive symptoms on developmental trajectories of cannabis use

This paper investigated how depressive symptoms moderate the role of peer cannabis use on developmental patterns of individual cannabis use from adolescence to young adulthood, controlling for a broad set of individual and family factors. Data from two sources were analyzed separately: two saturated schools in the National Longitudinal Study of Adolescent to Adult Health Waves I-III (N=1550) covering 1994-2001; and three schools in the CARBIN study, covering 2012-2014. Discrete mixture models identified developmental trajectories of cannabis use in each data source, and logit models linked network and depressive symptom information to the trajectories. Five similar cannabis use trajectories were identified in both datasets: Nonuse, Low, Moderate, Increasing, and High. Peer cannabis use at baseline predicted higher individual cannabis use trajectories, controlling for a wide range of factors. However, the association between peer cannabis use and higher levels of use (Moderate and High) attenuated as the adolescent's level of depressive symptoms increased. Although these results may suggest that depression dampers adolescents' susceptibility to peer influence, these results are also consistent with the notion that depressed adolescents withdraw from their peer groups, distancing them from the initial source of peer influence over time. The resulting isolation may place adolescents at higher risk of adverse outcomes.

Analytic Strategies for Longitudinal Networks with Missing Data

Missing data are often problematic when analyzing complete longitudinal social network data. We review approaches for accommodating missing data when analyzing longitudinal network data with stochastic actor-based models. One common practice is to restrict analyses to participants observed at most or all time points, to achieve model convergence. We propose and evaluate an alternative, more inclusive approach to sub-setting and analyzing longitudinal network data, using data from a school friendship network observed at four waves (N =694). Compared to standard practices, our approach retained more information from partially observed participants, generated a more representative analytic sample, and led to less biased model estimates for this case study. The implications and potential applications for longitudinal network analysis are discussed.

The dual role of friendship and antipathy relations in the marginalization of overweight children in their peer networks: The TRAILS Study

Weight-based stigma compromises the social networks of overweight children. To date, research on the position of overweight children in their peer network has focused only on friendship relations, and not on negative relationship dimensions. This study examined how overweight was associated with relations of friendship and dislike (antipathies) in the peer group. Exponential random graph models (ERGM) were used to examine friendship and antipathy relations among overweight children and their classmates, using a sub-sample from the TRacking Adolescents’ Individual Lives Survey (N = 504, M age 11.4). Findings showed that overweight children were less likely to receive friendship nominations, and were more likely to receive dislike nominations. Overweight children were also more likely than their non-overweight peers to nominate classmates that they disliked. Together, the results indicate that positive and negative peer relations are impacted by children’s weight status, and are relevant to addressing the social marginalization of overweight children.

Home visitation programs: an untapped opportunity for the delivery of early childhood obesity prevention

BACKGROUND

Extant obesity efforts have had limited impact among low-income underserved children, in part because of limitations inherent to existing programs: (i) short duration and low intensity; (ii) late timing of implementation, when children are already overweight or obese; (iii) intervention delivery limiting their accessibility and sustainability; and (iv) failure to address barriers such as a lack of culturally competent services, poverty and housing instability, which interfere with healthy lifestyle changes.

OBJECTIVE

This concept paper proposes an innovative model of obesity prevention implemented in infancy and sustained throughout early childhood to address the limitations of current obesity prevention efforts. Specifically, we propose to integrate sustained, weekly, in-home obesity prevention as part of the services already delivered by ongoing Home Visitation Programs, which currently do not target obesity prevention.

CONCLUSION

The home visiting structure represents an ideal model for impactful obesity prevention as home visitation programs: (i) already provide comprehensive services to diverse low-income infants and families who are most at risk for obesity and poor health because of socio-economic and structural conditions; (ii) services are initiated in infancy and sustained throughout critical developmental periods for the formation of healthy/unhealthy behaviors; and (iii) have been in place for more than 40 years, with a widespread presence across the United States and nationwide, which is critical for the scalability and sustainability of obesity prevention.

Whole of Systems Trial of Prevention Strategies for Childhood Obesity: WHO STOPS Childhood Obesity

Background: Community-based initiatives show promise for preventing childhood obesity. They are characterized by community leaders and members working together to address complex local drivers of energy balance. Objectives: To present a protocol for a stepped wedge cluster randomized trial in ten communities in the Great South Coast Region of Victoria, Australia to test whether it is possible to: (1) strengthen community action for childhood obesity prevention, and (2) measure the impact of increased action on risk factors for childhood obesity. Methods: The WHO STOPS intervention involves a facilitated community engagement process that: creates an agreed systems map of childhood obesity causes for a community; identifies intervention opportunities through leveraging the dynamic aspects of the system; and, converts these understandings into community-built, systems-oriented action plans. Ten communities will be randomized (1:1) to intervention or control in year one and all communities will be included by year three. The primary outcome is childhood obesity prevalence among grade two (ages 7-8 y), grade four (9-10 y) and grade six (11-12 y) students measured using our established community-led monitoring system (69% school and 93% student participation rate in government and independent schools). An additional group of 13 external communities from other regions of Victoria with no specific interventions will provide an external comparison. These communities will also allow us to assess diffusion of the intervention to control communities during the first three years of the trial. Conclusion: This trial will test effectiveness, over a five-year period, of community-owned, -supported and -led strategies designed to address complex and dynamic causes of childhood obesity.

Quantifying a Systems Map: Network Analysis of a Childhood Obesity Causal Loop Diagram

Causal loop diagrams developed by groups capture a shared understanding of complex problems and provide a visual tool to guide interventions. This paper explores the application of network analytic methods as a new way to gain quantitative insight into the structure of an obesity causal loop diagram to inform intervention design. Identification of the structural features of causal loop diagrams is likely to provide new insights into the emergent properties of complex systems and analysing central drivers has the potential to identify leverage points. The results found the structure of the obesity causal loop diagram to resemble commonly observed empirical networks known for efficient spread of information. Known drivers of obesity were found to be the most central variables along with others unique to obesity prevention in the community. While causal loop diagrams are often specific to single communities, the analytic methods provide means to contrast and compare multiple causal loop diagrams for complex problems.

Protocol for a randomized controlled trial testing the impact of feedback on familial risk of chronic diseases on family-level intentions to participate in preventive lifestyle behaviors

Background

Common disease risk clusters in families due to shared genetics, exposure to environmental risk factors, and because many health behaviours are established and maintained in family environments. This randomised controlled trial will test whether the provision of a family health history (FHH) risk assessment tool increases intentions and engagement in health behaviors. Message distribution and collective behavior change within family networks will be mapped using social network analysis. The relative intervention impact will be compared between families from different ethnic backgrounds.

Methods

One hundred and fifty mothers (50 Anglo-Australian, 50 Italian-Australian, 50 Vietnamese-Australian) will be recruited, with four or more other family members across three generations, including a child (aged 10–18 years). Each family is randomly assigned to intervention or control. At baseline and 6-month follow-up, all participants complete surveys to assess dietary and physical activity intentions and behaviors, attitudes towards food, and perceived disease risk. Intervention families receive a visual pedigree detailing their FHH of diabetes, heart disease, breast and bowel cancer, a health education workbook to ascertain members’ disease risk (i.e. average or above average risk), and screening and primary prevention recommendations. After completion of follow-up assessments, controls will receive their pedigree and workbook. The primary hypothesis is that attitudes and lifestyle behaviors will improve more within families exposed to FHH feedback, although the extent of this improvement may vary between families from different ethnic backgrounds. Additionally, the extent of improvement in the treatment group will be moderated by the level of family disease risk, with above-average risk leading to greater improvement. A secondary aim will explore different family members’ roles in message distribution and collective responses to risk using social network approaches and to compare network functioning between families with different ethnic backgrounds.

Discussion

Results will guide future health promotion programs aimed at improving lifestyle factors. This research will assess whether FHH can motivate families to adopt family-level strategies to support health promoting behaviors. Secondary analyses aim to identify change agents within the family who are particularly effective in shifting normative behaviors.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12613001033730. Retrospectively registered: 17 September, 2013.

The Power of Place: Social Network Characteristics, Perceived Neighborhood Features, and Psychological Distress Among African Americans in the Historic Hill District in Pittsburgh, Pennsylvania

African American neighborhoods have been historically targeted for urban renewal projects, which impact social composition and resident's health. The Hill District in Pittsburgh, PA is such a neighborhood. This research sought to investigate the extent to which social networks and perceived neighborhood social cohesion and safety were associated with psychological distress among residents in an African American neighborhood undergoing urban renewal, before the implementation of major neighborhood changes. Findings revealed a modest, significant inverse association between social network size and psychological distress (β = -0.006, p < .01), even after controlling for age, employment, education, and income. Perceived neighborhood safety predicted decreased psychological distress (β = -1.438, p < .01), but not social cohesion, which is consistent with past research. Findings suggest that social networks protect against psychological distress, but neighborhood perceptions are also paramount.

Let's Move Together

BACKGROUND

Due to shared health behaviors and disease risk, families may be more effective targets for health promotion. This study assessed whether providing family health history (FHH)-based risk information for heart disease and diabetes affected encouragement to engage in physical activity (PA) and healthy weight (HW) maintenance and co-engagement in physical activity among 320 Mexican-origin parents and their 1,081 children.

METHOD

At baseline and 10 months, parents indicated who they encouraged and who encouraged them to engage in PA/HW, and with whom they co-engaged in PA. Households were randomized to receive FHH-based assessments either by one or all adult household members. Primary analyses consisted of regression analyses using generalized estimating equations.

RESULTS

At baseline, parents reported encouraging their child for both PA and HW in 37.6% of parent-child dyads and reported receiving children's encouragement for both in 12.1% of dyads. These increased to 56.8% and 17.5% at 10 months ( p < .001). Co-engagement in PA increased from 11.4% to 15.7% ( p < .001), with younger children (30.4%) and mother-daughter dyads (26.8%) most likely to co-engage at 10 months. Providing FHH-based risk information to all adult household members (vs. one) was associated with increased parent-to-child encouragement of PA/HW ( p = .011) at 10 months but not child-to-parent encouragement. New encouragement from parent-to-child ( p = .048) and from child-to-parent ( p = .003) predicted new 10-month PA co-engagement.

DISCUSSION

Providing FHH information on a household level can promote parental encouragement for PA/HW, which can promote greater parent-child co-engagement in PA. In this high-risk population with a cultural emphasis on family ties, using FHH-based risk information for all adult household members may be a promising avenue to promote PA.

Longitudinal Associations of Homophobic Name-Calling Victimization With Psychological Distress and Alcohol Use During Adolescence

PURPOSE

Homophobic victimization, and specifically name-calling, has been associated with greater psychological distress and alcohol use in adolescents. This longitudinal study examines whether sexual orientation moderates these associations and also differentiates between the effects of name-calling from friends and nonfriends.

METHODS

Results are based on 1,325 students from three Midwestern high schools who completed in-school surveys in 2012 and 2013. Linear regression analysis was used to examine the associations among homophobic name-calling victimization and changes in anxiety symptoms, depressive symptoms, and alcohol use one year later, controlling for other forms of victimization and demographics.

RESULTS

Homophobic name-calling victimization by friends was not associated with changes in psychological distress or alcohol use among either students who self-identified as heterosexual or those who self-identified as lesbian, gay, or bisexual (LGB). In contrast, homophobic name-calling by nonfriends was associated with increased psychological distress over a one-year period among LGB students and increased drinking among heterosexual students.

CONCLUSIONS

Homophobic name-calling victimization, specifically from nonfriends, can adversely affect adolescent well-being over time and, thus, is important to address in school-based bullying prevention programs. School staff and parents should be aware that both LGB and heterosexual adolescents are targets of homophobic name-calling but may tend to react to this type of victimization in different ways. Further research is needed to understand the mechanisms through which homophobic victimization increases the risk of psychological distress and alcohol use over time.

Friendship Network Characteristics Are Associated with Physical Activity and Sedentary Behavior in Early Adolescence

INTRODUCTION

There is limited understanding of the association between peer social networks and physical activity (PA), sedentary and screen-related behaviors. This study reports on associations between personal network characteristics and these important health behaviors for early adolescents.

METHODS

Participants were 310 students, aged 11-13 years, from fifteen randomly selected Victorian primary schools (43% response rate). PA and sedentary behaviors were collected via accelerometer and self-report questionnaire, and anthropometric measures via trained researchers. Participants nominated up to fifteen friends, and described the frequency of interaction and perceived activity intensity of these friends. Personal network predictors were examined using regression modelling for PA and sedentary/screen behavior.

RESULTS

Perceived activity levels of friends, and friendships with very frequent interaction were associated with outside-of-school PA and/or sedentary/screen time. Differences according to sex were also observed in the association between network characteristics and PA and sedentary time. A higher number of friends and greater proportion of same sex friends were associated with boys engaging in more moderate-to-vigorous PA outside of school hours. PA intensity during school-day breaks was positively associated with having a greater proportion of friends who played sports for girls, and a greater proportion of male friends for boys.

CONCLUSION

Friendship network characteristics are associated with PA and sedentary/screen time in late childhood/early adolescence, and these associations differ by sex. The positive influence of very active peers may be a promising avenue to strengthen traditional interventions for the promotion of PA and reduction in screen time.

Befriending Risky Peers: Factors Driving Adolescents' Selection of Friends with Similar Marijuana Use

Adolescents often befriend peers who are similar to themselves on a range of demographic, behavioral, and social characteristics, including substance use. Similarities in lifetime history of marijuana use have even been found to predict adolescent friendships, and we examine whether this finding is explained by youth's selection of friends who are similar on a range of more proximate, observable characteristics that are risk factors for marijuana use. Using two waves of individual and social network data from two high schools that participated in Add Health (N = 1,612; 52.7% male), we apply longitudinal models for social networks to test whether or not several observable risky attributes (psychological, behavioral, and social) predict adolescent friendship choices, and if these preferences explain friend's similarities on lifetime marijuana use. Findings show that similarities on several risk factors predict friendship choices, however controlling for this, the preference to befriend peers with a similar history of marijuana use largely persists. The results highlight the range of social selection processes that lead to similarities in marijuana use among friends and larger peer groups, and that also give rise to friendship groups whose members share similar risk factors for substance use. Friends with high "collective risk" are likely to be important targets for preventing the onset and social diffusion of substance use in adolescents.

A prospective study of marijuana use change and cessation among adolescents

BACKGROUND

With marijuana use increasing among American adolescents, better understanding of the factors associated with decreasing use and quitting can help inform cessation efforts. This study evaluates a range of neighborhood, family, peer network, and individual factors as predictors of marijuana use, change, and non-use over one year, and cessation over six years.

METHODS

Data come from adolescents in Waves I and II of the National Longitudinal Study of Adolescent Health (N=458, one-year sample), or Waves I and III (N=358, six-year sample), and reported using marijuana at least four times in the past month at Wave I.

RESULTS

Eighteen percent of adolescents stopped using marijuana after six years. Results suggest neighborhood context affects overall use level, whereas neighborhood context and friends were critical to cessation vs. continuation of use. Decrease in use were more likely among adolescents in disadvantaged or less cohesive neighborhoods, or who moved between waves. Non-use after one year was more likely among adolescents who did not move, had fewer marijuana-using friends, and did not exclusively have outside-of-school friends. Cessation at six years was more likely among adolescents in less disadvantaged and more cohesive neighborhoods, and for those with within-school friends.

CONCLUSIONS

Results highlight the importance of both objective and subjective neighborhood characteristics, as well as peer networks, on adolescent marijuana use. Factors associated with decreases in use appear distinct from those that predict quitting, suggesting that continuation vs. cessation is linked to peers as well as neighborhood context. Relocated and isolated individuals may face challenges with cessation.

Covariance among multiple health risk behaviors in adolescents

PURPOSE

In a diverse group of early adolescents, this study explores the co-occurrence of a broad range of health risk behaviors: alcohol, cigarette, and marijuana use; physical inactivity; sedentary computing/gaming; and the consumption of low-nutrient energy-dense food. We tested differences in the associations of unhealthy behaviors over time, and by gender, race/ethnicity, and socioeconomic status.

METHODS

Participants were 8360 students from 16 middle schools in California (50% female; 52% Hispanic, 17% Asian, 16% White, and 15% Black/multiethnic/other). Behaviors were measured with surveys in Spring 2010 and Spring 2011. Confirmatory factor analysis was used to assess if an underlying factor accounted for the covariance of multiple behaviors, and composite reliability methods were used to determine the degree to which behaviors were related.

RESULTS

The measured behaviors were explained by two moderately correlated factors: a 'substance use risk factor' and an 'unhealthy eating and sedentary factor'. Physical inactivity did not reflect the latent factors as expected. There were few differences in the associations among these behaviors over time or by demographic characteristics.

CONCLUSIONS

Two distinct, yet related groups of health compromising behaviors were identified that could be jointly targeted in multiple health behavior change interventions among early adolescents of diverse backgrounds.

Peer influence on marijuana use in different types of friendships

PURPOSE

Although several social network studies have demonstrated peer influence effects on adolescent substance use, findings for marijuana use have been equivocal. This study examines whether structural features of friendships moderate friends' influence on adolescent marijuana use over time.

METHODS

Using 1-year longitudinal data from the National Longitudinal Study of Adolescent Health, this article examines whether three structural features of friendships moderate friends' influence on adolescent marijuana use: whether the friendship is reciprocated, the popularity of the nominated friend, and the popularity/status difference between the nominated friend and the adolescent. The sample consists of students in grade 10/11 at wave I, who were in grade 11/12 at wave II, from two large schools with complete grade-based friendship network data (N = 1,612).

RESULTS

In one school, friends' influence on marijuana use was more likely to occur within mutual, reciprocated friendships compared with nonreciprocated relationships. In the other school, friends' influence was stronger when the friends were relatively popular within the school setting or much more popular than the adolescents themselves.

CONCLUSIONS

Friends' influence on youth marijuana use may play out in different ways, depending on the school context. In one school, influence occurred predominantly within reciprocated relationships that are likely characterized by closeness and trust, whereas in the other school adopting friends' drug use behaviors appeared to be a strategy to attain social status. Further research is needed to better understand the conditions under which structural features of friendships moderate friends' influence on adolescent marijuana use.

Selection and Influence Mechanisms Associated With Marijuana Initiation and Use in Adolescent Friendship Networks

Friends are thought to influence adolescent drug use. However, few studies have examined the role of drugs in friendship selection, which is necessary to draw sound conclusions about influence. This study applied statistical models for social networks to test the contribution of selection and influence to associations in marijuana use among friends in two large high schools (N = 1,612; M age = 16.4). There was evidence for friend selection based on similar lifetime and current marijuana use at both schools, but friends were found to influence the initiation and frequency of adolescent marijuana use in just one of these schools. There was minimal evidence that peer effects were moderated by personal, school, or family risk factors.