Thomas Valente

Thomas Valente
University of Southern California | USC · Department of Preventive Medicine

PhD

About

244
Publications
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Introduction
Skills and Expertise

Publications

Publications (244)
Article
Full-text available
Background Specialized cancer survivorship clinics are recommended for addressing treatment-related health concerns of long-term survivors, but their relative newness in medical oncology necessitates strategies to expand services and clinic referrals. This study used social network analysis to identify personal and/or network factors associated wit...
Article
Full-text available
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 sc...
Conference Paper
Introduction: E-cigarette use in the United States has continued to increase since its introduction a decade ago, but reasons for e-cigarette use are still poorly understood. Although several studies have examined popular concepts in e-cigarette users’ health beliefs on social media, connections between these concepts and their relationships with o...
Conference Paper
Introduction. Walking is associated with lower risk of premature death. Studies have tested a variety of walking interventions; however, results have varied substantially. The limited understanding of when to deliver different types of prompts is a key barrier to developing a just-in-time adaptive intervention (JITAI) for walking. This study aimed...
Article
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 ti...
Article
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Background Health system approaches to improve hypertension control require an effective referral network. A national referral strategy exists in Kenya; however, a number of barriers to referral completion persist. This paper is a baseline assessment of a hypertension referral network for a cluster-randomized trial to improve hypertension control a...
Article
Purpose: Considerable evidence has shown that social networks influence a wide variety of health behaviors. This study investigates whether having friends with overweight/obesity in one's social network (network exposure) can predict changes in body mass index (BMI) throughout high school in a diverse urban population of students. Methods: Racially...
Chapter
Addressing the proliferation of poor diets and related diseases requires new initiatives that will change food systems. How to change these systems is a challenging question. We argue that a promising approach is to leverage the network of social actors who make up the backbone of food systems, who can influence peoples’ eating behaviors and the br...
Article
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Objectives: Management of cardiovascular disease (CVD) is an urgent challenge in low-income and middle-income countries, and interventions may require appraisal of patients' social networks to guide implementation. The purpose of this study is to determine whether egocentric social network characteristics (SNCs) of patients with chronic disease in...
Article
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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 6...
Article
In the current article, we describe an innovative sexual violence (SV) prevention initiative that used social network analysis to identify youth and adult popular opinion leaders who were subsequently trained in best practices in SV prevention (e.g., bystander intervention) at a kickoff event (i.e., camp) of the initiative. We provide information o...
Article
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Background Incorporating social determinants of health into care delivery for chronic diseases is a priority. Objectives The goal of this study was to evaluate the impact of group medical visits and/or microfinance on blood pressure reduction. Methods The authors conducted a cluster randomized trial with 4 arms and 24 clusters: 1) usual care (UC)...
Article
E-cigarette use has been increasing among middle school students. Intervention programs to prevent e-cigarette initiation administered by authority figures are met with more resistance from youth compared to peer-led programs. Therefore, this study aimed to assess the feasibility, acceptability, and implementation process of using social network an...
Article
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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 i...
Article
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Background After the US Surgeon General declared youth electronic cigarette (e-cigarette) use an epidemic in 2018, the number of youth e-cigarette users continued to surge, growing from 3.8 million in 2018 to over 5 million 2019. Youth who use e-cigarettes are at a substantially higher risk of transitioning to traditional cigarettes, becoming regul...
Article
Full-text available
Coronavirus disease of 2019 (COVID-19)’s devastating effects on the physical and mental health of the public are unlike previous medical crises, in part because of people’s collective access to communication technologies. Unfortunately, a clear understanding of the diffusion of health information on social media is lacking, which has a potentially...
Article
Background: We tested efficacy of a peer change agent Type I network intervention to increase PrEP linkage to care among network members connected to young Black men who have sex with men. Methods: We randomly assigned 423 participants in Chicago to receive the network intervention, an opinion leader workshop with telephonic booster sessions, ve...
Article
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This article introduces social network analysis (SNA), a theoretical perspective accompanied by a set of methodologies, to occupational science. The convergence of SNA and occupational science is timely for both fields. By providing methodological approaches that flesh out a structural view of social networks, SNA measurements and mathematical term...
Article
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Adolescents experiencing depressive symptoms tend to withdraw from social interaction, but patterns among Latinx LGBT youth (i.e., lesbian, gay, bisexual, transgender) are unclear. Latinx adolescents in the Greater Los Angeles Area (N = 549) were surveyed during two consecutive years, and longitudinal relationships among depressive symptoms, parent...
Article
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 South...
Article
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Background: Non-communicable disease (NCD) care in Sub-Saharan Africa is challenging due to barriers including poverty and insufficient health system resources. Local culture and context can impact the success of interventions and should be integrated early in intervention design. Human-centered design (HCD) is a methodology that can be used to en...
Article
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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 inde...
Article
Purpose Weight stigmatization during adolescence may compromise the development of social relations important for the development. This study examined the associations between weight status and likelihood of nomination (indegree) for five different social network types—friendship, romantic, admiration, succeed, and popularity. Methods Data for the...
Article
Full-text available
This study models how new ideas, practices, or diseases spread within and between communities, the diffusion of innovations or contagion. Several factors affect diffusion such as the characteristics of the initial adopters, the seeds; the structure of the network over which diffusion occurs; and the shape of the threshold distribution, which is the...
Article
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...
Article
Background: Compared to other racial groups, Hispanic/Latino(a) adolescents experience higher rates of alcohol (ab)use and alcohol-related problems. Evidence suggests there are gender differences in alcohol use patterns indicating the likelihood of gender differences in how various determinants influence alcohol use among the genders. Assessing th...
Article
Introduction The Strengthening Referral Networks for Management of Hypertension Across the Health System (STRENGTHS) trial is creating and testing interventions to improve the effectiveness of referral networks for patients with hypertension in Western Kenya. Purpose Network analysis of facility-based healthcare providers was used to understand th...
Article
Researchers collecting survey data on inter-organizational networks typically choose a single informant with the most senior job title in each organization from whom to obtain a report of the organization’s inter-organizational ties. This approach to informant selection is based on the logic that greater seniority confers greater knowledge of inter...
Article
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Background: Hypertension is a major risk factor for cardiovascular disease (CVD), yet treatment and control rates for hypertension are very low in low- and middle-income countries (LMICs). Lack of effective referral networks between different levels of the health system is one factor that threatens the ability to achieve adequate blood pressure co...
Article
Full-text available
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,...
Article
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 scho...
Article
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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 school...
Article
Full-text available
Background: Ineffective referral networks in low- and middle-income countries hinders access to evidence-based therapies by hypertensive patients, leading to high cardiovascular mortality and morbidity. The STRENGTHS (Strengthening Referral Networks for Management of Hypertension Across Health Systems) study evaluates strategies to improve referra...
Article
This paper examines whether country implementation of a public health treaty is influenced by the implementation behaviors of other countries to which they have network ties. We examine implementation of the Framework Convention on Tobacco Control (FCTC) adopted by the World Health Organization in 2003 and ratified by approximately 94% of countries...
Article
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Background: Peer-led interventions have been applied to prevent various health behavior problems and may be an important complement to individual-level suicide prevention approaches. Sources of Strength trains student “peer leaders” in secondary schools to conduct prevention activities that encourage other students to build healthy social bonds and...
Article
Full-text available
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...
Article
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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...
Article
We examined social mechanisms that account for similarity in the social context of school-sponsored extracurricular sports activities among friends. We distinguish two social mechanisms: “shared sports activities that lead to friendship,” whereby friendship formation and maintenance are conditioned by joint sports participation, and “friendship tha...
Article
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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 car...
Article
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Health information-seeking behaviour of mothers with children five years of age and younger in Vanuatu was examined using the structural properties of social networks. Data were collected from a rural village from two islands and an urban settlement in the capital, Port Vila, by face-to-face interviews using a structured questionnaire. Sociometric...
Article
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Purpose of the Review India is not only one of the largest producers of tobacco in the world, but is also one of the largest consumers of tobacco products. Adolescents and young adults are the most vulnerable to tobacco addiction as early initiation is predictive of long-term use and health risks. This review seeks to provide an overview of policie...
Article
Background: Heroin use is increasing in the US. Heroin use may predispose users towards injection routes of drug administration as compared to other illicit substances. Objective: To explore the relationship between heroin use and drug injection, we compared time from first use to first injection (referred to as time to injection onset by drug [TTI...
Article
Full-text available
Background Social networks influence health behavior, including tobacco use and cessation. To date, little is known about whether and how the networks of online smokers and non-smokers may differ, or the potential implications of such differences with regards to intervention efforts. Understanding how social networks vary by smoking status could in...
Article
GLOBALink, a large online network of tobacco control professionals, was active in the promotion of the World Health Organization's Framework Convention on Tobacco Control treaty, an international treaty aimed at reducing the global burden of tobacco-related death and disease. We examined and compared the roles that different countries served in the...
Article
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...
Article
Full-text available
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...
Article
This study investigates potential bias that may arise when surveys include question items for which multiple units are elicited. Examples of such items include questions about experiences with multiple health centers, comparison of different products, or the solicitation of egocentric network data. The larger the number of items asked about each na...
Article
Various centrality indices have been proposed to capture different aspects of structural importance but relations among them are largely unexplained. The most common strategy appears to be the pairwise comparison of centrality indices via correlation. While correlation between centralities is often read as an inherent property of the indices, we ar...
Article
Objectives. To demonstrate the use of evaluation data in determining the effectiveness of a series of community-based educational seminars designed to educate substance abuse treatment counselors on the latest science regarding the effects of alcohol abuse on diseases of the liver and pancreas; in the process, to highlight the use of difference sco...
Article
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...
Chapter
Full-text available
Social network theory focuses on the role of social relationships in transmitting information, channeling personal or media influence, and enabling attitudinal or behavioral change. Since the 1960s, social network theory has significantly expanded the horizon of media effects research, with increasing application of network analytic methods in vari...
Article
In this study, we examined the dynamics of the perception of “dislike” ties (reputational dislike) among adolescents within the contexts of friendship, perceived popularity, substance use, and Facebook use. Survey data were collected from a longitudinal sample of 238 adolescents from the 11th and 12th grades in one California high school. We estima...
Article
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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 resear...
Article
Background: Scientists have established that social networks influence adolescents' substance use behavior, an influence that varies by gender. However, the role of gender in this mechanism of influence remains poorly understood. Particularly, the role an adolescent's gender, alongside the gender composition of his/her network, plays in facilitati...
Article
Full-text available
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 resear...
Article
Online networks can serve as a platform to diffuse policy innovations and enhance global health governance. This study focuses on how shifts in global health governance may influence related online networks. We compare social network metrics (average degree centrality [AVGD], density [D] and clustering coefficient [CC]) of Globalink, an online netw...
Article
Full-text available
This study applies an ecological perspective to the context of community-based participatory research (CBPR). Specifically, it examines how endogenous and exogenous factors influence the dynamics of CBPR partnerships, including the tendency toward reciprocity and transitivity, the organizational type, the level of resource sufficiency, the level of...
Article
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Background: Sustaining prevention efforts directed at substance use and mental health problems is one of the greatest, yet least understood, challenges in the field of implementation science. A large knowledge gap exists regarding the meaning of the term "sustainment" and what factors predict or even measure sustainability of effective prevention...
Article
Background: Family structure and value system among Hispanic/Latino population are changing. However, very few studies are examining the combination of the influence of family structure, parental and sibling alcohol use, perceived peer norms about drinking, and alcohol use among Hispanic/Latino adolescents. Purpose: This study examined the assoc...
Article
Full-text available
Objectives. To examine the diffusion of an evidence-based smoking cessation application ("app") through Facebook social networks and identify specific intervention components that accelerate diffusion. Methods. Between December 2012 and October 2013, we recruited adult US smokers ("seeds") via Facebook advertising and randomized them to 1 of 12 app...
Article
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Background Although many behavioral interventions have proven to be efficacious, new methodologies are required beyond efficacy trials to understand how to adopt, implement with fidelity, and sustain behavioral interventions in community settings. In this paper, we present a new approach, based on systems engineering concepts and methods, for chara...
Article
Full-text available
Social networks, particularly those defined by friendships, influence many childhood and adolescent health behaviors such as the use of alcohol, tobacco, and other drugs, as well as diet and physical activity. Few, if any, studies have examined the concordance between friendship networks and sun exposure/safety behaviors. This study examines the fr...