Search

BackgroundThe United States is currently in an age of obesity and inactivity despite increasing public awareness and scientific knowledge of detrimental long-term health effects of this lifestyle. Behavior-tracking diaries offer an effective strategy for physical activity adherence and weight management. Furthermore, Web-based physical activity diaries can engage meaningful partners in people’s social networks through fun online gaming interactions and generate motivational mechanisms for effective behavioral change and positive health outcomes. ObjectiveWellness Partners (WP) is a Web-based intervention in the form of a physical activity diary with social networking and game features. Two versions were designed and developed for the purpose of this study—“Diary” only and “Diary+Game”. The objectives of this study included pilot testing the research process of this intervention design, implementation, evaluation, and exploring the effectiveness of social gaming features on adult participants’ physical activity and anthropometric measures. MethodsWe conducted a field experiment with randomized crossover design. Assessments occurred at baseline, first follow-up (FU, 5-8 weeks after using one version of WP), and second FU (5-8 weeks of using the other version of WP). In the control condition, participants started with the “Diary” version of WP while in the experimental condition, participants started with the “Diary+Game” version of WP. A total of 54 adults (egos) ages 44-88, and their family and friends (alters) ages 17-69 participated in the study in ego-network groups. Both egos and their alters completed online surveys about their exercise habits. In addition, egos completed anthropometric measurements of BMI, fat percentage, and fat mass by bioimpedance. ResultsFrom October 2009 to May 2010, flyers, emails, and Web advertisements yielded 335 volunteers who were screened. Rolling recruitment resulted in enrollment of 142 qualified participants in 54 ego-network groups, which were randomly assigned to a study condition. The final analytic sample included 87 individuals from 41 groups. Data were collected from December 2009 to August 2010, and data analysis was completed in 2011. Overall, the participants were given access to the intervention for 10-13 weeks. Statistical analysis suggested an increase in self-reported exercise frequency (mean days per week) from baseline (2.57, SD 1.92) to first FU (3.21, SD 1.74) in both conditions. Stronger effects were seen in the condition where Diary+Game was played first, especially in network groups with larger age variation between the alters and egos. Overall, the decrease in egos’ BMI was statistically significant from baseline to first FU, with greater decrease for those in the Diary+Game first condition (-0.26 vs -0.16 in the Diary first condition). ConclusionsThe Wellness Partners program increased physical activity among participants and resulted in health benefits among the egos. Web-based diary interventions designed with social gaming features hold potential to promote active lifestyles for middle-age adults and people in their social networks.

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, parental support-seeking, and loneliness were examined for differences based on youth's LGBT identity. LGBT identity moderated the relationship between baseline depressive symptoms and subsequent parental support-seeking, such that higher baseline depressive symptoms predicted less subsequent parental support-seeking for non-LGBT youth, but not for LGBT youth. The relationship between parental support-seeking and depressive symptoms, both at Time 2, was moderated by LGBT identity, such that more support-seeking tended to correspond with fewer depressive symptoms for non-LGBT youth, but the opposite tended to occur for LGBT youth. Results suggest a subgroup effect, such that LGBT Latinx adolescents may seek parental support differently than their non-LGBT Latinx peers in the context of depressive symptoms.

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 proportion of prior adopting peers needed for the focal individual to adopt. In this study, seven seeding conditions are modeled: (1) three opinion leadership indicators, (2) two bridging measures, (3) marginally positioned seeds, and (4) randomly selected seeds for comparison. Three network structures are modeled: (1) random, (2) small-world, and (3) scale-free. Four threshold distributions are modeled: (1) normal; (2) uniform; (3) beta 7,14; and (4) beta 1,2; all of which have a mean threshold of 33%, with different variances. The results show that seeding with nodes high on in-degree centrality and/or inverse constraint has faster and more widespread diffusion. Random networks had faster and higher prevalence of diffusion than scale-free ones, but not different from small-world ones. Compared with the normal threshold distribution, the uniform one had faster diffusion and the beta 7,14 distribution had slower diffusion. Most significantly, the threshold distribution standard deviation was associated with rate and prevalence such that higher threshold standard deviations accelerated diffusion and increased prevalence. These results underscore factors that health educators and public health advocates should consider when developing interventions or trying to understand the potential for behavior change.

BackgroundHeroin use is increasing in the US. Heroin use may predispose users towards injection routes of drug administration as compared to other illicit substances.ObjectiveTo 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 [TTIOD]) of heroin, methamphetamine/speed, cocaine, and crack cocaine among people who inject drugs (PWID).MethodsAge of first use and first injection by drug was collected from 776 PWID. Survival analyses were used to determine TTIOD and to examine demographic factors associated with TTIOD. Cox regression analysis was used to determine demographic factors associated with drug-specific injection onset.ResultsThe eventual injection onset rate by the drug was 99% for participants who used heroin, 85% for participants who used methamphetamine/speed, 80% for participants who used powder cocaine, and 38% for participants who used crack cocaine. Hazard ratios for injection use within one year of first use by drug were: 1.37 (median survival time [MST] = 0.61 years) for heroin, 0.66 (MST = 1.10 years) for methamphetamine/speed, 0.50 (MST = 2.93 years) for powder cocaine, and 0.12 (MST = 39.59 years) for crack cocaine. Demographic differences in TTIOD were found for each drug. Demographic differences were found for eventual injection by drug for all substances except heroin.ConclusionAmong PWID, heroin use was associated with a more rapid transition to injection and a higher rate of eventual heroin injection regardless of demographics. More robust, innovative efforts to reduce heroin use and prevent injection initiation are urgently needed.

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 the mechanisms that contribute to Hispanic adolescents' alcohol use requires an understanding of the multidimensional social and environmental processes that operate together to impact their alcohol use. In this study, we examined socio-ecological determinants of Hispanic adolescent alcohol use by gender. Methods: Data from 10th grade Hispanic/Latino(a) students (N = 781) from four high schools in Los Angeles were used to examine associations between socio-ecological characteristics and adolescent alcohol use by gender. Results: Overall, 37.5% of participants reported past 30-day alcohol use. Among boys, alcohol use was associated with intrapersonal (not qualifying for reduced lunch), interpersonal (mother's education and peer drinking), and institutional (alcohol-prone school club membership) determinants. Among girls, alcohol use was associated with intrapersonal (academic achievement) and interpersonal (parent and peer alcohol use behavior) determinants. Conclusions: Prevention and intervention efforts need to take into consideration the gender differences in social-ecological risk and protective factors when designing educational or intervention programs and services targeted at Hispanic adolescents. This is crucial to addressing multi-component factors that influence their substance use behavior.

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 organizational influence, and the perceived CBPR effect on organizations. The results demonstrate that network structure is related to the selection and retention of interorganizational networks over time, and organizations of the same type are more likely to form partnerships with each other. It shows that the dynamics of the CBPR initiative presented in this article were driven by the structure of the interorganizational networks rather than their individual organizational attributes. Implications for sustaining CBPR partnerships are drawn from the findings.

ObjectiveThe purpose of this exploratory study was to validate and extend previous research on social support by identifying which dimensions of social support are most commonly exchanged on health-related social networking sites and how social network structure varies with each support dimension exchanged.MethodsThis research applies a multiple case study approach by examining two social networking sites that focus on pregnancy and prenatal health. For one month, support seeking and providing messages were content analyzed and a social network analysis examined the connections between members.ResultsThe sample size consisted of 525 support-seeking messages and 1965 support-providing messages. Findings indicate that participants requested informational and emotional support more than esteem and network support, with no requests for tangible support. Findings also suggest participants substituted emotional support for informational support when they were unable to provide the information sought. The social network analysis showed that network structure varied across support dimensions, with the informational and emotional support networks having the largest number of members and greatest density and reciprocity.ConclusionsThis study suggests that online support networks are fairly effective in meeting participants' needs. The support dimension sought was generally provided and when it was not another dimension of support may have been substituted; thus, participants may have benefitted in unintended ways. The data also suggest there may be an optimal network size to support member engagement, whereby too large of a network may facilitate diffusion of responsibility and too small a network may not facilitate enough momentum to support a well-connected community.

Injection drug-using men from the US and Mexico who purchase sex in Tijuana, Mexico are at risk for transmitting HIV to their contacts in both countries via syringe sharing. We used social network methods to understand whether place of residence (US vs. Mexico) moderated the effect of emotional closeness on syringe sharing. We interviewed 199 drug-using men who reported paying/trading for sex in Tijuana, Mexico using an epidemiological and social network survey and collected samples for HIV/STI testing. Seventy-two men reported using injection drugs with 272 network contacts. Emotional closeness was strongly associated with syringe sharing in relationship where the partner lives in the US, while the relationship between emotional closeness and syringe sharing was considerably less strong in dyads where the partner lives in Mexico. Efforts to reduce HIV risk behaviors in emotionally close relationships are needed, and could benefit from tailoring to the environmental context of the relationship.

This study evaluated the feasibility of measuring diffusion from a social networking community-level intervention. One year after completion of a randomized controlled HIV prevention trial on Facebook, 112 minority men who have sex with men (MSM) were asked to refer African-American and/or Latino sex partners to complete a survey. Results suggest that, compared to non-referrers, referrers spent more time online, controlling for age, race, education, and condition. Over 60% of referrals reported hearing about the intervention, and over half reported that the referrer talked to them about changing health behaviors. Results provide support and initial feasibility of using social networking for diffusing community-based HIV interventions.

ContextFew U.S. women use an IUD, despite the method's efficacy and ease of use. While studies have found that misconceptions about IUDs are prevalent, few have examined the influence of women's social networks on perceptions of the method.MethodsTwenty-four interviews and three focus groups (comprising 14 participants) were conducted in 2013 with a diverse sample of women aged 15-45 recruited from family planning clinics and the community in San Francisco. Half of participants had used IUDs. Women were asked about their social communication concerning contraceptives, particularly IUDs, and about the content of the information they had received or given. Transcripts were analyzed using a modified grounded theory approach to identify themes of interest.ResultsWomen reported that communication with female friends and family members was a valued means of obtaining information about contraceptives, and that negative information (which often was incorrect) was more prevalent and memorable than positive information in such communication. Women heard about negative experiences with IUDs from social contacts and television commercials; clinicians were a major source of positive information. Women who had never used IUDs expressed interest in learning about potential side effects and how IUDs feel, while users reported emphasizing to friends and family the method's efficacy and ease of use.ConclusionsMisinformation and negative information about IUDs are prevalent in social communication, and the information transmitted through social networks differs from the information never-users wish to receive. Findings support the creation of peer-led interventions to encourage IUD users to share positive personal experiences and evidence-based information.

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. Highlights: This study examined how victimization and perpetration cluster within adolescents' social networks.Utilization of social network analyses allowed us to understand interactions between youth and their peers over time.Longitudinal findings provide support for the importance of victims' peer networks over time. [ABSTRACT FROM AUTHOR]

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 named individual or location, the greater potential interviewer and respondent burden accrues to the naming of more names. Interviewers may be inclined to limit the number of names elicited to reduce the amount of time required to complete the interviews. We tested whether such bias occurred from data collected in northwest Ghana by contrasting group learning with individual learning. The results provided mixed evidence for both group and individual learning and stress the need to take actions such as increased training, change in incentives, and/or monitoring responses to guard against such results.

BackgroundGiven the importance of influence networks in the implementation of evidence-based practices and interventions, it is unclear whether such networks continue to operate as sources of information and advice when they are segmented and disrupted by randomization to different implementation strategy conditions. The present study examines the linkages across implementation strategy conditions of social influence networks of leaders of youth-serving systems in 12 California counties participating in a randomized controlled trial of community development teams (CDTs) to scale up use of an evidence-based practice.MethodsSemi-structured interviews were conducted with 38 directors, assistant directors, and program managers of county probation, mental health, and child welfare departments. A web-based survey collected additional quantitative data on information and advice networks of study participants. A mixed-methods approach to data analysis was used to create a sociometric data set (n = 176) to examine linkages between treatment and standard conditions.ResultsOf those network members who were affiliated with a county (n = 137), only 6 (4.4%) were directly connected to a member of the opposite implementation strategy condition; 19 (13.9%) were connected by two steps or fewer to a member of the opposite implementation strategy condition; 64 (46.7%) were connected by three or fewer steps to a member of the opposite implementation strategy condition. Most of the indirect steps between individuals who were in different implementation strategy conditions were connections involving a third non-county organizational entity that had an important role in the trial in keeping the implementation strategy conditions separate. When these entities were excluded, the CDT network exhibited fewer components and significantly higher betweenness centralization than did the standard condition network.ConclusionAlthough the integrity of the RCT in this instance was not compromised by study participant influence networks, RCT designs should consider how influence networks may extend beyond boundaries established by the randomization process in implementation studies.Trial registrationNCT00880126.

ObjectivesWe sought to determine whether a community-based initiative designed to reduce cancer disparities among Pacific Islanders in Southern California increased communications between community-based organizations and university researchers.MethodsWe conducted network analysis among 11 community-based organizations (CBOs) and 5 universities by interviewing 91 and 56 members of these organizations, respectively, at 2 points in time. We estimated random effects probit regression and stochastic actor-oriented network dynamic models.ResultsWe found that, during the 2-year study period, CBOs increased their connectedness with one another (b= 0.44; P < .05) and to the universities (b = 0.46; P < .05), but that university researchers did not increase their connectedness to each other or to CBOs.ConclusionsCancer awareness, cancer education, and access to cancer services are low among Pacific Island groups, and this study provides an initial attempt to reduce these disparities. Community-based initiatives can strengthen a CBO network, creating the potential for increased community-informed cancer research and improved community access to cancer research resources.