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.

Social Network Influences on Adolescent E-cigarette Use.

Background: Determine if individual adolescent vaping is associated with the vaping behavior of their school-based friendships; whether that association stems from peer influence or peer selection; and whether it varies by age. Methods: Two wave longitudinal survey of 1,208 students in one Midwestern US school district. Students were asked if they ever vaped and to name their seven closest friends within the school district. A roster of all eligible students was pre-loaded into the survey to facilitate network data collection. Terms for network exposure, the proportion of vaping friends; and selection, the number of new friends who vape, were created. Logistic regression and Stochastic Actor Oriented Models were used to test both influence and selection effects. Results: A cross-sectional logistic regression model indicated that friend vaping was associated with individual vaping (AOR = 4.96, p < 0.01); and lagged logistic models indicated that increased friend vaping was associated with individual vaping initiation (AOR = 1.72, p < 0.05). Selecting new friends who vape was also associated with becoming a vaper (AOR = 1.25, p < 0.01). Both influence and selection were present for those less than 14 years old. Conclusions: This is the first study to use social network analysis to show that adolescents who vape or initiate vaping are more likely to do so if their friends vape, and/or they make new friends who vape. Prevention and cessation programs should address the role of friend influence and selection on e-cigarette use; particularly at younger ages.

Social networks and violence victimization and perpetration among youth: A longitudinal analysis.

Interpersonal violence (IV) is a serious concern for adolescents in the United States that has devastating impacts for individuals and communities. Given the increased importance placed on friendships during adolescence, the purpose of the current study was to examine the extent to which IV experiences cluster within youths' friendship networks. Participants were students (N = 1303) in grades 7th to 10th who completed surveys at the beginning and end of an academic year. Results showed that friends' average perpetration (i.e., the percentage of the friends they nominated who perpetrated IV) was strongly associated with likelihood of individual perpetration at baseline but not at the follow-up. For victimization, friends' average report of victimization (i.e., the percentage of the friends they nominated who were victimized) was associated with higher likelihood reporting of victimization (at both baseline and follow-up). Although future research is needed to understand explanatory mechanisms underlying these findings, it is possible that the effectiveness of prevention initiatives may be enhanced by incorporating peer group information.

Diffusion effects of a sexual violence prevention program leveraging youth-adult partnerships.

The purpose of the current study was to examine the diffusion effects of a youth-led sexual violence prevention program (i.e., Youth Voices in Prevention [Youth VIP]). Specifically, social network analysis was used to measure the extent to which Youth VIP changed behaviors for 1172 middle and high school youth who did not attend program events but were friends with Youth VIP participants and completed the first and final survey (approximately 2 years apart). Findings suggest that there was considerable interpersonal communication about Youth VIP among the students generated by program participation. Specifically, youth with friends who participated in Youth VIP were more likely to report hearing their friends talk about Youth VIP and reported talking to their friends about Youth VIP compared with those not connected to Youth VIP participants. However, there were no diffusion effects found for behavioral outcomes (i.e., bystander intervention behavior, violence victimization, and perpetration). Given the mixed findings, further research is needed to determine the extent to which youth-led sexual violence prevention initiatives lead to changes in broader community-wide changes in youths' behaviors.

A comparison of peer change agent selection methods: Evidence from a high-school based suicide preventive intervention.

BACKGROUND: Peer-led interventions for adolescents are effective at accelerating behavioral change. The Sources of Strength suicide preventive program trains student peer change agents (peer leaders) in secondary schools to deliver prevention messaging and conduct activities that increase mental health coping mechanisms. The program currently has school staff select peer leaders. This study examined potential for more efficient program diffusion if peer leaders had been chosen under network-informed selection methods. METHODS: Baseline assessments were collected from 5,746 students at 20 schools. Of these, 429 were selected by adults as peer leaders who delivered intervention content through the school year. We created theoretical alternate peer leader sets based on social network characteristics: opinion leadership, centrality metrics, and key players. Because these sets were theoretical, we examined the concordance of these sets with the actual adult-selected peer leaders sets and correlated this metric with diffusion of intervention modalities (i.e., presentation, media, communication, activity) after the first year. RESULTS: The sets of adult-selected peer leaders were 13.3%-22.7% similar to theoretical sets chosen by other sociometric methods. The use of friendship network metrics produced peer leader sets that were more white and younger than the general student population; the Key Players method produced more representative peer leader sets. Peer opinion leaders were older and more white than the general population. Schools whose selected peer leaders had higher overlap with theoretical ones had greater diffusion of intervention media and peer communication. CONCLUSIONS: The use of network information in school-based peer-led interventions can help create more systematized peer leader selection processes. To reach at-risk students, delivery of an indirect message, such as through a poster or video, may be required. A hybrid approach where a combination of visible, respected opinion leaders, along with strategically-placed key players within the network, may provide the greatest potential for intervention diffusion.

The stability of youth popular opinion leaders selected over time using social network analysis.

Community interventions that use social network analysis to identify and involve influential individuals are promising for behavior change. However, youth friendships are often unstable. The current study examined the stability of the youth selected as influential in a friendship social network, that is, the degree to which youth selected at one time point were also selected at subsequent time points. Influential youth, also called popular opinion leaders (POLs), were selected to be part of a community-wide sexual violence prevention initiative. POLs were selected based on high in-degree (number of times an individual was nominated as a best friend by another student). We found that POLs were unstable: only 29.81%-41.01% of POLs were stable across time. The percentage of POLs who were stable decreased across time. No factors (social identities, behavioral, attitudinal) consistently predicted POL stability. Although these findings are in need of replications, social network interventions for youth may need to repeatedly select new POLs to account for instability.

Associations between network-level acculturation, individual-level acculturation, and substance use among Hispanic adolescents.

Acculturation is associated with substance use behaviors in Hispanic adolescents. However, there is limited research determining whether the individual's friends' acculturation patterns also influence substance use. Tenth-grade students (N = 970) participated in Project RED, a study of substance use and social networks among Hispanic youth in Southern California. Acculturation and substance use data from both the respondent and their nominated friends were regressed on lifetime cigarette use, marijuana use, and alcohol use controlling for sibling substance use, sex, depressive symptoms, and network measures. Respondent's Hispanic orientation was significantly associated with lower odds of both cigarette and marijuana use, whereas respondent's friends' US orientation was associated with higher odds of cigarette use. When controlling for network-level acculturation, individual-level U.S. orientation was not associated with substance use. Participants who nominated more friends had lower odds of cigarette use. Among this sample of Hispanic adolescents, affiliating with U.S.-oriented friends was associated with a higher risk for smoking. Substance use prevention efforts should consider encouraging Hispanic youth to maintain their cultural heritage and foster friendship groups that support abstinence and promote Hispanic and bicultural identity.

Disrupting the COVID-19 Misinfodemic With Network Interventions: Network Solutions for Network Problems.

Amid the COVID-19 global pandemic, a highly troublesome influx of viral misinformation threatens to exacerbate the crisis through its deleterious effects on public health outcomes and health behavior decisions.This "misinfodemic" has ignited a surge of ongoing research aimed at characterizing its content, identifying its sources, and documenting its effects. Noticeably absent as of yet is a cogent strategy to disrupt misinformation.We start with the premise that the diffusion and persistence of COVID-19 misinformation are networked phenomena that require network interventions. To this end, we propose five classes of social network intervention to provide a roadmap of opportunities for disrupting misinformation dynamics during a global health crisis. Collectively, these strategies identify five distinct yet interdependent features of information environments that present viable opportunities for interventions.

Evaluation of a Nurse-Delivered Pre-Chemotherapy Educational Intervention to Increase Knowledge and Reduce Anxiety Among Ethnically Diverse Patients.

Patients who are undergoing chemotherapy for cancer often have high-unmet information and psychological needs at the beginning of their treatment. Pre-chemotherapy education is an oncology nursing standard of care. However, few pre-chemotherapy education interventions have reported on their effectiveness among ethnically diverse samples. The aim of the study was to evaluate the implementation of an oncology nurse-led pre-chemotherapy intervention delivered to an ethnically diverse sample of patients treated at a comprehensive cancer center on day one of their first chemotherapy cycle. The aim of the intervention was to increase knowledge about treatment in order to improve patient self-management and to reduce treatment-related anxiety. We found that the intervention was effective in improving patient self-reported knowledge and decreasing treatment-related anxiety; however, differential effects were found for Hispanic/Latino patients, whose anxiety increased post-intervention, as well as for patients who reported poorer health status. These findings suggest that further research should investigate what factors trigger an increase in anxiety among diverse patient populations, and how these factors can be mitigated through development of tailored and culturally competent interventions.

The Connectedness of Mental Health Providers Referring Patients to a Treatment Study for Post-Traumatic Stress: A Social Network Study.

We conducted a process evaluation in the context of a Hybrid Type 1 randomized controlled trial testing two treatments for post-traumatic stress, using a web-based social network survey and semi-structured interviews to illustrate the relationship between providers' influence and likelihood of referring patients to the RCT. Providers with high indegree centrality (designated by other providers as someone they seek information from) were significantly more likely to refer patients to the RCT, and serve as an influence to others' referral behavior. Interviews provided additional data to consider for future studies aimed at increasing the uptake of evidence-based practices.

Social network interventions for health behaviours and outcomes: A systematic review and meta-analysis.

BACKGROUND: There has been a growing interest in understanding the effects of social networks on health-related behaviour, with a particular backdrop being the emerging prominence of complexity or systems science in public health. Social network interventions specifically use or alter the characteristics of social networks to generate, accelerate, or maintain health behaviours. We conducted a systematic review and meta-analysis to investigate health behaviour outcomes of social network interventions. METHODS AND FINDINGS: We searched eight databases and two trial registries from 1990 to May 28, 2019, for English-language reports of randomised controlled trials (RCTs) and before-and-after studies investigating social network interventions for health behaviours and outcomes. Trials that did not specifically use social networks or that did not include a comparator group were excluded. We screened studies and extracted data from published reports independently. The primary outcome of health behaviours or outcomes at ≤6 months was assessed by random-effects meta-analysis. Secondary outcomes included those measures at >6-12 months and >12 months. This study is registered with the International Prospective Register of Systematic Reviews, PROSPERO: CRD42015023541. We identified 26,503 reports; after exclusion, 37 studies, conducted between 1996 and 2018 from 11 countries, were eligible for analysis, with a total of 53,891 participants (mean age 32.4 years [SD 12.7]; 45.5% females). A range of study designs were included: 27 used RCT/cluster RCT designs, and 10 used other study designs. Eligible studies addressed a variety of health outcomes, in particular sexual health and substance use. Social network interventions showed a significant intervention effect compared with comparator groups for sexual health outcomes. The pooled odds ratio (OR) was 1.46 (95% confidence interval [CI] 1.01-2.11; I2 = 76%) for sexual health outcomes at ≤6 months and OR 1.51 (95% CI 1.27-1.81; I2 = 40%) for sexual health outcomes at >6-12 months. Intervention effects for drug risk outcomes at each time point were not significant. There were also significant intervention effects for some other health outcomes including alcohol misuse, well-being, change in haemoglobin A1c (HbA1c), and smoking cessation. Because of clinical and measurement heterogeneity, it was not appropriate to pool data on these other behaviours in a meta-analysis. For sexual health outcomes, prespecified subgroup analyses were significant for intervention approach (p < 0.001), mean age of participants (p = 0.002), and intervention length (p = 0.05). Overall, 22 of the 37 studies demonstrated a high risk of bias, as measured by the Cochrane Risk of Bias tool. The main study limitations identified were the inclusion of studies of variable quality; difficulty in isolating the effects of specific social network intervention components on health outcomes, as interventions included other active components; and reliance on self-reported outcomes, which have inherent recall and desirability biases. CONCLUSIONS: Our findings suggest that social network interventions can be effective in the short term (<6 months) and longer term (>6 months) for sexual health outcomes. Intervention effects for drug risk outcomes at each time point were not significant. There were also significant intervention effects for some other health outcomes including alcohol misuse, well-being, change in HbA1c, and smoking cessation.

Peer-adult network structure and suicide attempts in 38 high schools: implications for network-informed suicide prevention.

BACKGROUND: Strengthening social integration could prevent suicidal behavior. However, minimal research has examined social integration through relationship network structure. To address this important gap, we tested whether structural characteristics of school networks predict school rates of ideation and attempts. METHODS: In 38 US high schools, 10,291 students nominated close friends and trusted adults to construct social networks. We used mixed-effects logistic regression models to test individual student networks and likelihood of suicidal ideation (SI) and suicide attempts (SA); and linear regression models to estimate associations between school network characteristics and school rates of SI, SA, and SA among all with ideation. RESULTS: Lower peer network integration and cohesion increased likelihood of SI and SA across individual and school-level models. Two factors increased SA: student isolation from adults and suicidal students' popularity and clustering. A multivariable model identified higher SA in schools where youth-adult relationships were concentrated in fewer students (B = 4.95 [1.46, 8.44]) and suicidal students had higher relative popularity versus nonsuicidal peers (B = 0.93 [0.10, 1.77]). Schools had lower SA rates when more students named the same trusted adults named by friends and many students named the same trusted adults. When adjusting for depression, violence victimization and bullying, estimates for adult network characteristics were substantially unchanged whereas some peer effects decreased. CONCLUSIONS: Schoolwide peer and youth-adult relationship patterns influence SA rates beyond individual student connections. Network characteristics associated with suicide attempts map onto three theory-informed domains: social integration versus thwarted relational needs, group cohesion, and suicidal students' social influence. Network interventions addressing these processes, such as maximizing youth-adult connections schoolwide and heightening influence of youth with healthy coping, could create more protective schools. Longitudinal and intervention studies are needed to determine how schools differentiate in network structure and clarify reciprocal dynamics between network characteristics and suicidal behavior.

Involving end-users in the design of an audit and feedback intervention in the emergency department setting - a mixed methods study.

BACKGROUND: Long length of stays (LOS) in emergency departments (ED) negatively affect quality of care. Ordering of inappropriate diagnostic tests contributes to long LOS and reduces quality of care. One strategy to change practice patterns is to use performance feedback dashboards for physicians. While this strategy has proven to be successful in multiple settings, the most effective ways to deliver such interventions remain unknown. Involving end-users in the process is likely important for a successful design and implementation of a performance dashboard within a specific workplace culture. This mixed methods study aimed to develop design requirements for an ED performance dashboard and to understand the role of culture and social networks in the adoption process. METHODS: We performed 13 semi-structured interviews with attending physicians in different roles within a single public ED in the U.S. to get an in-depth understanding of physicians' needs and concerns. Principles of human-centered design were used to translate these interviews into design requirements and to iteratively develop a front-end performance feedback dashboard. Pre- and post- surveys were used to evaluate the effect of the dashboard on physicians' motivation and to measure their perception of the usefulness of the dashboard. Data on the ED culture and underlying social network were collected. Outcomes were compared between physicians involved in the human-centered design process, those with exposure to the design process through the ED social network, and those with limited exposure. RESULTS: Key design requirements obtained from the interviews were ease of access, drilldown functionality, customization, and a visual data display including monthly time-trends and blinded peer-comparisons. Identified barriers included concerns about unintended consequences and the veracity of underlying data. The surveys revealed that the ED culture and social network are associated with reported usefulness of the dashboard. Additionally, physicians' motivation was differentially affected by the dashboard based on their position in the social network. CONCLUSIONS: This study demonstrates the feasibility of designing a performance feedback dashboard using a human-centered design approach in the ED setting. Additionally, we show preliminary evidence that the culture and underlying social network are of key importance for successful adoption of a dashboard.

Perceived Social Acceptability and Longitudinal Trends in Adolescent Cigarette Smoking.

The current study uses methods from social network analysis to predict longitudinal trends in adolescent cigarette smoking based on perceived social acceptability from friends, in addition to typical measures of peer influence (e.g., self-reported cigarette use of friends). By concurrently investigating the role of perceived social acceptability of smoking and peer influence, the current study offers new insight into the mechanisms through which peers influence adolescent smoking. Two waves of data from five high schools within one US school district (n = 1563) were used. Stochastic actor-based models simultaneously estimated changes in smoking predicted by perceived social acceptability and peer influence. Findings demonstrate that adolescents with higher perceived social acceptability of cigarette use increased cigarette smoking over time. Conversely, support for peer influence on smoking was not found after controlling for the effects of perceived social acceptability. The results suggest that perceived social acceptability regarding cigarette smoking rather than self-report of cigarette use among friends is predictive of future smoking behavior. Consequently, the findings highlight the need for prevention efforts to take into account the multifaceted dynamics between adolescent smoking and friendships. Programs that address peer influence alone, without considering peer mechanisms such as perceived social acceptability, are at risk of ignoring critical avenues for prevention.

Overlooked Threats to Respondent Driven Sampling Estimators: Peer Recruitment Reality, Degree Measures, and Random Selection Assumption.

Intensive sociometric network data were collected from a typical respondent driven sample (RDS) of 528 people who inject drugs residing in Hartford, Connecticut in 2012-2013. This rich dataset enabled us to analyze a large number of unobserved network nodes and ties for the purpose of assessing common assumptions underlying RDS estimators. Results show that several assumptions central to RDS estimators, such as random selection, enrollment probability proportional to degree, and recruitment occurring over recruiter's network ties, were violated. These problems stem from an overly simplistic conceptualization of peer recruitment processes and dynamics. We found nearly half of participants were recruited via coupon redistribution on the street. Non-uniform patterns occurred in multiple recruitment stages related to both recruiter behavior (choosing and reaching alters, passing coupons, etc.) and recruit behavior (accepting/rejecting coupons, failing to enter study, passing coupons to others). Some factors associated with these patterns were also associated with HIV risk.

PrEP Chicago: A randomized controlled peer change agent intervention to promote the adoption of pre-exposure prophylaxis for HIV prevention among young Black men who have sex with men.

BACKGROUND/AIMS: Advances in biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) represent a new opportunity for reducing HIV incidence among young Black men who have sex with men, for whom the number of new HIV infections continues to rise. However, studies have documented low rates of PrEP uptake in this community. Research suggests that the peer networks of young Black men who have sex with men play important roles in their sexual health decisions. PrEP Chicago is a randomized controlled trial network intervention designed to increase PrEP uptake among young Black men who have sex with men living in Chicago. The aims of this study are twofold. Aim 1 is to estimate the effectiveness of a peer change agent intervention for (1) increasing the number of referrals made to a PrEP information line, (2) increasing the rate of PrEP adoption among non-participant peers, and (3) increasing PrEP knowledge, attitudes, and intentions among participants. Aim 2 is to determine the individual and network variables that explain peer change agent effectiveness. METHODS: PrEP Chicago is a social network intervention that utilizes the influence of peer change agents to link young Black men who have sex with men in Chicago to PrEP. Young Black men who have sex with men were recruited using respondent-driven sampling. Once screened for eligibility, participants were randomly assigned to either one of two treatment sequences: (1) intervention treatment in Year 1 followed by a minimal contact attention control in Year 2 or (2) the minimal contact attention control in Year 1 followed by treatment in Year 2. The treatment consists of a PrEP/peer change agent training workshop followed by booster calls for 12 months. The attention control consists of a sex diary activity designed to help participants assess sexual risk. Psychosocial, sexual health, and network data are collected from all participants at baseline and at 12- and 24-month follow-ups. RESULTS: In total, 423 participants aged 18-35 have been enrolled (more than 100% target enrollment) and have completed baseline data collection. A majority of participants in both intervention and control groups reported having heard of PrEP before enrolling in the study, yet also reported having had no current or prior experience taking PrEP. Statistical analyses await completion of Year 1 of the trial in March 2018. CONCLUSION: PrEP Chicago addresses a gap in HIV prevention research and intervention design by utilizing the existing social networks among young Black men who have sex with men as mechanisms for information diffusion, behavioral influence, social support, and empowerment. Therefore, interventions that leverage peer influence processes to facilitate PrEP uptake are promising strategies to improve sexual health engagement and overcome disparities in outcomes among this at-risk population.

Interpersonal communication regarding pregnancy-related services: friends versus health professionals as conduits for information.

BACKGROUND: Social network characteristics influence a wide range of health behaviors but few studies examine the relationship between social network characteristics and pregnancy-related outcomes. METHODS: Using a baseline survey from a behavior change pilot project in the Upper West region of Ghana, we examine four outcomes: (1) early antenatal care, (2) having at least four antenatal care visits, (3) skilled birth attendance, and (4) postpartum care. We collected demographic and network data from 1606 women of reproductive age who had a child in the five years preceding the survey. We estimated associations by regressing the four pregnancy-related outcomes on the demographic and network characteristics. RESULTS: The results suggest that there is little interpersonal communication about pregnancy-related issues, as 60.2% of respondents reported talking to no one. For those women who did talk to someone, communication with a health professional had the strongest association with accessing services (e.g., Adjusted Odds Ratio [AOR] = 8.02, p < 0.01, for having a facility birth). Communicating with friends was also significantly associated with outcomes (AOR = 4.23, p < 0.0, for having a facility birth). CONCLUSIONS: This study provides evidence that there was little social communication about pregnancy-related issues in these communities at that time, indicating that an intervention to promote such communication could be successful. In addition, women who reported discussing pregnancy-related issues with friends or a health professional were more likely to access a birth facility and have a skilled birth attendant than those who reported discussing the same topics with their partner.

"You See Yourself Like in a Mirror": The Effects of Internet-Mediated Personal Networks on Body Image and Eating Disorders.

Body image issues associated with eating disorders involve attitudinal and perceptual components: individuals' dissatisfaction with body shape or weight, and inability to assess body size correctly. While prior research has mainly explored social pressures produced by the media, fashion, and advertising industries, this paper focuses on the effects of personal networks on body image, particularly in the context of internet communities. We use data collected on a sample of participants to websites on eating disorders, and map their personal networks. We specify and estimate a model for the joint distribution of attitudinal and perceptual components of body image as a function of network-related characteristics and attributional factors. Supported by information gathered through in-depth interviews, the empirical estimates provide evidence that personal networks can be conducive to positive body image development, and that the influence of personal networks varies significantly by body size. We situate our discussion in current debates about the effects of computer-mediated and face-to-face communication networks on eating disorders and related behaviors.

Bridging Income Generation with Group Integrated Care for cardiovascular risk reduction: Rationale and design of the BIGPIC study.

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality worldwide, with >80% of CVD deaths occurring in low and middle income countries (LMICs). Diabetes mellitus and pre-diabetes are risk factors for CVD, and CVD is the major cause of morbidity and mortality among individuals with DM. There is a critical period now during which reducing CVD risk among individuals with diabetes and pre-diabetes may have a major impact. Cost-effective, culturally appropriate, and context-specific approaches are required. Two promising strategies to improve health outcomes are group medical visits and microfinance. METHODS/DESIGN: This study tests whether group medical visits integrated into microfinance groups are effective and cost-effective in reducing CVD risk among individuals with diabetes or at increased risk for diabetes in western Kenya. An initial phase of qualitative inquiry will assess contextual factors, facilitators, and barriers that may impact integration of group medical visits and microfinance for CVD risk reduction. Subsequently, we will conduct a four-arm cluster randomized trial comparing: (1) usual clinical care, (2) usual clinical care plus microfinance groups only, (3) group medical visits only, and (4) group medical visits integrated into microfinance groups. The primary outcome measure will be 1-year change in systolic blood pressure, and a key secondary outcome measure is 1-year change in overall CVD risk as measured by the QRISK2 score. We will conduct mediation analysis to evaluate the influence of changes in social network characteristics on intervention outcomes, as well as moderation analysis to evaluate the influence of baseline social network characteristics on effectiveness of the interventions. Cost-effectiveness analysis will be conducted in terms of cost per unit change in systolic blood pressure, percent change in CVD risk score, and per disability-adjusted life year saved. DISCUSSION: This study will provide evidence regarding effectiveness and cost-effectiveness of interventions to reduce CVD risk. We aim to produce generalizable methods and results that can provide a model for adoption in low-resource settings worldwide.

An Appraisal of Social Network Theory and Analysis as Applied to Public Health: Challenges and Opportunities.

The use of social network theory and analysis methods as applied to public health has expanded greatly in the past decade, yielding a significant academic literature that spans almost every conceivable health issue. This review identifies several important theoretical challenges that confront the field but also provides opportunities for new research. These challenges include (a) measuring network influences, (b) identifying appropriate influence mechanisms, (c) the impact of social media and computerized communications, (d) the role of networks in evaluating public health interventions, and (e) ethics. Next steps for the field are outlined and the need for funding is emphasized. Recently developed network analysis techniques, technological innovations in communication, and changes in theoretical perspectives to include a focus on social and environmental behavioral influences have created opportunities for new theory and ever broader application of social networks to public health topics.