Let's Move Together

Social network characteristics associated with mid-to-older aged adults' co-engagement in physical activity

OBJECTIVES

Physical activity is associated with a greater quantity and quality of social connections. Participating in physical activity with others (co-engagement) has dual physical and social benefits that can promote healthy ageing. We aimed to understand the social network characteristics of mid-to-older aged adults associated with co-engagement in physical activity.

METHODS

Adults aged 55-75 years completed a social network survey (3679 social contacts reported by 140 participants). Multilevel modelling was used to identify the characteristics of participants, social contacts, and relationships that were predictive of co-engagement in physical activity.

RESULTS

Network size and relationship quality were not associated with co-engagement. Similarity in age, greater interaction frequency, closer geographic proximity, and shorter relationship length were associated with higher odds of co-engagement.

DISCUSSION

For co-engagement, the quality and quantity of relationships were less important than the convenience and accessibility of relationships, particularly newer relationships. As such, co-engagement ties can be understood as part of a dynamic social convoy which fulfil a specific function at a specific life stage. An understanding of naturally occurring tendencies for co-engagement may be utilised to identify leverage points for the development of interventions.

Developing and assessing a kin keeping scale with application to identifying central influencers in African American family networks

Promoting family communication about inherited disease risk is an arena in which family systems theory is highly relevant. One family systems' construct that can support promotion of family communication regarding inherited disease risk is the notion of "kin keeping." However, kin keeping and whether it might be capitalized on to encourage family communication about inherited risk has been understudied. The goal of this report was to propose a broadened conceptualization of kin keeping that distinguishes between a structural functional perspective (role conceptualization) and transitional behaviors (skill conceptualization), and to develop and evaluate a scale that would enable this assertion to be tested among a sample of African American community health workers. We developed a scale using four steps: item development using concept analysis and content validity, scale development among a national sample (n = 312), scale evaluation using exploratory factor analysis (n = 52), and scale reduction. We then posed suppositions of associations that would indicate whether the developed kin keeping measure was assessing a specific family role or set of behaviors. Our results included the development of the first quantitative measure of kin keeping (9- and 15-item scales). Model fit for 9-item scale (CFI = 0.97, AFGI = 0.89, RMSEA = 0.09, SMRM = 0.06) and model fit for 15-item scale (CFI = 0.97, AFGI = 0.89, RMSEA = 0.06, SMRM = 0.05). These findings allow us to move toward more rigorous research about the role of kin keeping on information sharing and health decision making. Results also suggest that, contrary to the historical structural functional conceptualization of kin keeping as a role, kin keeping might also be conceptualized as a behavior or set of modifiable behaviors. Ultimately, the kin keeping scale could be used to operationalize kin keeping in various theoretical models and frameworks, guide intervention development to encourage or train for kin keeping behaviors, and test assumptions of whether families vary in the density of kin keeping.

Understanding the Process of Family Cancer History Collection and Health Information Seeking

PROBLEM ADDRESSED

To better understand the factors associated with family cancer history (FCH) information and cancer information seeking, we model the process an individual undergoes when assessing whether to gather FCH and seek cancer information and compare models by sociodemographics and family history of cancer. We used cross-sectional data from the Health Information National Trends Survey (HINTS 5, Cycle 2) and variables (e.g., emotion and self-efficacy) associated with the Theory of Motivated Information Management to assess the process of FCH gathering and information seeking. We completed path analysis to assess the process of FCH gathering and stratified path models.

RESULTS

Those who felt they could lower their chances of getting cancer (emotion) were more confident in their ability to complete FCH on a medical form (self-efficacy; B = 0.11, p < .0001) and more likely to have discussed FCH with family members (B = 0.07, p < .0001). Those who were more confident in their ability to complete a summary of their family history on a medical form were more likely to have discussed FCH with family members (B = 0.34, p < .0001) and seek other health information (B = 0.24, p < .0001). Stratified models showed differences in this process by age, race/ethnicity, and family history of cancer.

IMPLICATIONS FOR PUBLIC HEALTH RESEARCH AND PRACTICE

Tailoring outreach and education strategies to address differences in perceived ability to lower chances of getting cancer (emotion) and confidence in the ability to complete FCH (self-efficacy) could help encourage less engaged individuals to learn about their FCH and gather cancer information.

Shared Responsibility and Network Collaboration in Caregiving

Communal coping may benefit caregivers, but most communal coping research focuses on dyads. Using an egocentric network design, we examine caregivers' we-talk-a linguistic marker of shared responsibility-and caregiver reports of 1) network member involvement in collaborative care roles and 2) met/unmet expectations across typically developing and rare disease contexts. We-talk was linked to involvement in direct care and support, but links of we-talk to decision-making varied based on network member closeness; we-talk was linked to meeting expectations for decision-making only. There were no differences across context, suggesting shared responsibility is linked to collaborative roles across caregiving contexts.

Pasos Hacia La Salud II: study protocol for a randomized controlled trial of a theory- and technology-enhanced physical activity intervention for Latina women, compared to the original intervention

Background

Latinas are at increased risk for many lifestyle-related chronic diseases and are one of the least physically active populations in the US Innovative strategies are needed to help Latinas achieve the health benefits associated with physical activity (PA). This manuscript describes the study protocol of the Pasos Hacia La Salud II Study, which builds upon our previous research to test an enhanced individually-tailored, text-message and website-delivered, Spanish-language intervention (enhanced intervention), in comparison to the original web-based Pasos Hacia La Salud Intervention (original intervention).

Methods

Sedentary Latinas between the ages of 18–65 will be recruited and will complete an orientation and baseline assessments. Participants will be subsequently randomized to the original intervention, or the Enhanced Intervention, which has greater targeting of theoretical constructs such as self-efficacy, enjoyment, and social support, and which uses text messages and more dynamic and refined website features to encourage increased website use. Using a linear mixed effects regression model, we will simultaneously estimate the intervention effects on mean accelerometer-measured hours/week of moderate-to-vigorous PA (MVPA) at 6, 12, 18, and 24 months, with a subject-specific intercept (intent-to-treat sample). Change in self-reported MVPA, measured via the 7-day Physical Activity Recall, will be assessed as a secondary outcome using a similar model. We will investigate potential mediators of the intervention effect using a multiple mediation approach, and potential moderators by evaluating potential interactions. As an exploratory outcome, we will study the differences (among both study arms) in cost, in US dollars, per minute increases in weekly mean MVPA.

Discussion

The original Pasos PA intervention showed efficacy in helping Latinas increase PA; we expect the Enhanced Intervention to help a larger proportion of participants to increase and maintain their PA long term. This web- and text-based enhanced intervention could have great reach and dissemination potential, which could be capitalized on in the future to help to advance health equity. Adaptations made in response to the COVID-19 pandemic are also described in this manuscript.

Trial registration

Clinical Trial Number: NCT03491592. First posted April 9, 2018.

Remote acculturation and physical activity among adolescent-mother dyads in Jamaica: A developmental dyadic moderation

This study examined the associations between remote acculturation to European American culture, hereafter United States (U.S.) American culture, and physical activity levels among Jamaican mother-adolescent dyads. Remote acculturation, a modern type of globalization-facilitated acculturation to a distant non-native culture, is a demonstrated risk factor for some health outcomes, but the association with physical activity has not previously been examined. Mothers and adolescents (N = 660; 330 dyads) were recruited from schools in Kingston, Jamaica. Actor-Partner Interdependence Moderation Models tested hypotheses about actor and partner effects of U.S. cultural orientation on moderate and vigorous physical activity (MVPA), and the moderation of these effects by developmental stage, socioeconomic status (SES), and gender. We observed a contrast pattern of moderation, such that the signs of the actor and partner effects depended on adolescent developmental stage. The actor effect of adolescents' U.S. orientation on their own MVPA was negative for early adolescents (unexpected) and positive for mid-adolescents (expected); by contrast, the partner effect of mother's U.S. orientation on adolescents' MVPA was positive for early adolescents (expected) and negative for mid-adolescents (unexpected). SES and gender did not moderate the associations. This study contributes to an emerging body of literature on the health correlates of remote acculturation. Our results suggest that whether remote cultural orientation is a risk or protective factor varies based on the health domain in question, developmental stage, the remote culture, and the context.

Factors Influencing Family Health History Collection among Young Adults: A Structural Equation Modeling

Family health history (FHH) can serve as an entry point for preventive medicine by providing risk estimations for many common health conditions. College is a critical time for young adults to begin to understand the value of FHH collection, and to establish healthy behaviors to prevent FHH-related diseases. This study seeks to develop an integrated theoretical framework to examine FHH collection behavior and associated factors among college students. A sample of 2670 college students with an average age of 21.1 years completed a web-based survey. Less than half (49.8%) reported actively seeking FHH information from their family members. Respondents’ knowledge about FHH were generally low. Structural equation modeling findings suggested an adequate model fit between our survey data and the proposed integrated theoretical framework. Respondents who were members of racial/ethnic minority groups exhibited higher levels of anxiety and intention to obtain FHH information but had lower confidence in their ability to gather FHH information than non-Hispanic White respondents. Therefore, educational programs designed to enhance the level of young adults’ FHH knowledge, efficacy, and behavior in FHH collection, and change subjective norms are critically needed in the future, especially for these who are members of racial/ethnic minority groups.

Optimization of an mHealth lifestyle intervention for families with hereditary cancer syndromes: Study protocol for a multiphase optimization strategy feasibility study

BACKGROUND

Individuals at increased hereditary risk of cancer are an important target for health promotion and cancer prevention interventions. Health-4-Families uses the Multiphase Optimization STrategy (MOST) framework and is designed to pilot digital delivery strategies for a distance-based, 16-week intervention to promote weight management, healthy diet, and increased physical activity among individuals with BRCA1/BRCA2 or DNA mismatch repair (MMR) pathogenic germline variants. This communication describes participant recruitment and the design of the Health-4-Families pilot study.

METHODS

Health-4-Families is a full-factorial (16 condition) randomized pilot study of four lifestyle intervention components: social networking, telephone or email coaching, text messaging, and self-monitoring. The primary outcome was feasibility and satisfaction with these study components. Participants with pathogenic germline variants were identified via clinic surveillance lists and advocacy organizations and were invited to participate with family members. All participants had to report meeting at least one of the following criteria: (1) having a BMI ≥ 25 kg/m2, (2) consuming <5 servings of fruit and vegetables per day, or (3) getting <150 min of moderate-to-vigorous intensity activity per week.

RESULTS

The majority of screened potential participants with pathogenic variants (83%) were eligible; 86% of those eligible provided informed consent and 79% (n = 104) completed baseline. A total of 206 family members were nominated by study participants and 49% (n = 102) completed baseline.

DISCUSSION

Recruitment data suggest that individuals with pathogenic germline variants, who are at increased risk for hereditary cancers, are motivated to participate in digital lifestyle interventions. This recruitment success highlights the importance of identifying and prioritizing effective and efficient intervention components for hereditary cancer families. We intend to use the outcomes of our pilot study to inform a fully-powered factorial study for this community.

Quantifying parent engagement in the randomized Fuel for Fun impact study identified design considerations and BMI relationships

BACKGROUND

Parent participation in children's health interventions is insufficiently defined and measured. This project quantified parent participation to enable future examination with outcomes in an intervention focused on 4th graders, aged 9-11 years, and their families living in northern Colorado.

METHODS

Indices were developed to measure type (Parent Participation Profile; PPP) and intensity (Parent Engagement Intensity; PEI) of engagement in Fuel for Fun (FFF), an asymmetric school-and family-based intervention for 4th graders. Study arm-specific participation opportunities were catalogued and summed to calculate the PPP. An algorithm considered frequency, effort, convenience, and invasiveness of each activity to calculate PEI. Indices were standardized (0-100%) using study arm-specific divisors to address asymmetric engagement opportunities. Parents who completed ≥75% of the PPP were defined as Positive Deviants. Youth height and weight were measured. Youth BMI percentile change was compared with parent Positive Deviant status using general linear modeling with repeated measures that included the participation indices.

RESULTS

Of 1435 youth, 777 (54%) had parent participation in at least one activity. Standardized means were 41.5 ± 25.4% for PPP and 27.6 ± 20.9% for PEI. Demographics, behaviors or baseline FFF outcomes did not differ between the Positive Deviant parent (n = 105) and non-Positive Deviant parents (n = 672); but more Positive Deviant parents followed an indulgent feeding style (p = 0.015). Standardized intensity was greater for Positive Deviant parents; 66.9 ± 20.6% vs 21.5 ± 12.7% (p < 0.001) and differences with non-Positive Deviant parents were related to activity type (p ≤0.01 for six of eight activities). Standardized participation intensity was associated with engagement in a greater number of standardized activity types. Among participating parents, standardized intensity and breadth of activity were inversely related to the youth BMI percentile (n = 739; PEI r = -0.39, p < 0.001; PPP r = -0.34, p < 0.001). Parent engagement was not associated with parent BMI change.

CONCLUSIONS

An activity-specific intensity schema operationalized measurement of parent engagement in a complex, unbalanced research design and can serve as a template for more sensitive assessment of parent engagement. Positive deviance in parent engagement was not a function of personal, but rather activity characteristics. PPP and PEI increased with fewer requirements and convenient, novel, and personalized activities. Parent engagement indices affirmed lower engagement by parents of overweight/obese youth and concerns about target reach.

Family Health History-Based Interventions: A Systematic Review of the Literature

CONTEXT

National efforts have advocated for the need to deliver family health history-based interventions to the lay public for more than a decade. Yet, the numbers, characteristics, and outcomes of such interventions are unknown. This first-of-its-kind systematic literature review examines the characteristics and effectiveness of the existing family health history-based interventions.

EVIDENCE ACQUISITION

The research team systematically searched peer-reviewed articles published between January 2003 and July 2020 in MEDLINE, Embase, CINAHL, and Google Scholar.

EVIDENCE SYNTHESIS

A total of 35 articles met the inclusion criteria. These studies assessed various behaviors, including family health history collection/communication with family members, family health history communication with healthcare providers, healthy diet adoption, physical activity level, uptake of medical screenings and genetic tests, and being proactive in healthcare matters. The average methodologic quality score of the studies was 9.9 (SD=1.6) of a theoretical range from 2 to 16.

CONCLUSIONS

Many family health history-based interventions exist to examine a variety of behaviors. Yet, there is room for improvement in methodology because few studies used a randomized or quasi-experimental design. In addition, most included studies did not report objective or longer-term outcome data to examine the effectiveness of family health history-based interventions.

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.

Social and behavioral science at the forefront of genomics: Discovery, translation, and health equity

This special issue highlights the unique role that social and behavioral science has to play at the forefront of genomics. Through the introduction of papers comprising this special issue, we outline priority research areas at the nexus of genomics and the social and behavioral sciences. These include: Discovery science; clinical and community translation, and equity, including engagement and inclusion of diverse populations in genomic science. We advocate for genomic discovery that considers social context, neural, cognitive, and behavioral endophenotypes, and that is grounded in social and behavioral science research and theory. Further, the social and behavioral sciences should play a leadership role in identifying best practices for effective clinical and community translation of genomic discoveries. Finally, inclusive research that engages diverse populations is necessary for genomic discovery and translation to benefit all. We also highlight ways that genomics can be a fruitful testbed for the development and refinement of social and behavioral science theory. Indeed, an expanded ecological lens that runs from genomes to society will be required to fully understand human behavior.

Activating Communal Coping Related to Diabetes Risk in Mexican-Heritage Families

We investigate how interpersonal ties influence communication about type 2 diabetes risk and encouragement to maintain or adopt a healthy lifestyle between family members of Mexican heritage, after a family history-based risk assessment intervention. Results suggest that individuals are more likely to initiate risk communication with another family member if they are close to, already seek advice from, or discuss health with him or her. Risk communication precedes encouragement, which is initiated by the older generation of the family. Understanding the role of interpersonal relationships in Mexican-heritage families can help identify who best to target in future health behavior interventions.

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).

Perceived weight and barriers to physical activity in parent-adolescent dyads

OBJECTIVE

Family-based physical activity interventions have the potential to reduce obesity, but more information is needed regarding physical activity in the family context. This study used an actor-partner interdependence model to estimate the dyadic association between perceived weight status and barriers to physical activity in dyads of adults and their adolescent children. It was hypothesized that greater perceived weight would be associated with greater barriers perceived by both one's self and one's partner.

METHOD

Data from 1,568 dyads in the Family Life, Activity, Sun, Health, and Eating study were used to examine the dyadic association between perceived weight status (i.e., greater perceived weight category) and barriers to physical activity. Models were stratified by actual weight (an overweight or obese dyad member vs. two normal weight dyad members) and adjusted for parent education, parent and adolescent age, gender, and race.

RESULTS

Among dyads with at least 1 overweight/obese member, greater perceived weight status was positively associated with one's own perceived barriers (significant actor effects, βs = 1.17 and 1.03, ps < 0.01) and one's partner's perceived barriers (significant partner effects, βs = 0.38 and 0.62, ps < 0.01). No statistically significant relationships were found for dyads with only normal weight members.

CONCLUSIONS

Among dyads with at least 1 overweight or obese member, significant partner effects for parents and adolescents demonstrate that the weight perception of 1 dyad member correlates with the barriers of the other member. These dyadic associations highlight the potential importance of family-based interventions for physical activity. (PsycINFO Database Record

Social and behavioral science priorities for genomic translation

This commentary highlights the essential role of the social and behavioral sciences for genomic translation, and discusses some priority research areas in this regard. The first area encompasses genetics of behavioral, social, and neurocognitive factors, and how integration of these relationships might impact the development of treatments and interventions. The second area includes the contributions that social and behavioral sciences make toward the informed translation of genomic developments. Further, there is a need for behavioral and social sciences to inform biomedical research for effective implementation. The third area speaks to the need for increased outreach and education efforts to improve the public's genomic literacy such that individuals and communities can make informed health-related and societal (e.g., in legal or consumer settings) decisions. Finally, there is a need to prioritize representation of diverse communities in genomics research and equity of access to genomic technologies. Examples from National Institutes of Health-based intramural and extramural research programs and initiatives are used to discuss these points.

Developing Shared Appraisals of Diabetes Risk Through Family Health History Feedback: The Case of Mexican-Heritage Families

Background

Collecting complete and accurate family health history is critical to preventing type 2 diabetes.

Purpose

We seek to identify the optimal risk feedback approach that facilitates risk communication between parents and their adult children and helps them develop shared appraisals of family history of type 2 diabetes.

Methods

In a sample of parent-adult child dyads from 125 Mexican-heritage families residing in Houston, Texas, we examine change in parent-child dyadic (dis)agreement with respect to their shared family health history from baseline to 10 months after receipt of risk feedback generated by Family Healthware. A 2 × 2 factorial design is applied to test how the recipient (one parent or all family members) and the content (risk assessment with or without behavioral recommendations) of the feedback affect (dis)agreement through interpersonal ties, particularly dyadic risk communication.

Results

Providing risk assessment without behavioral recommendations to the parent, but not the adult child, shifts the dyads toward agreement (relative risk ratio [RRR]= 1.78, 95% confidence interval [CI] [1.18-2.67]), by activating reciprocal risk communication between parents and children (RRR =2.70, 95% CI [1.81-4.03]). Dyads with close interpersonal ties are more likely to shift toward agreement (RRR = 3.09, 95% CI [1.89-5.07]).

Conclusion

Programs aimed at improving family health history knowledge and accuracy of reports should tailor risk feedback strategically for better intervention effect and leverage a network approach in disease prevention among at-risk minority and/or immigrant populations.

Trial Registration Number

NCT00469339.

Heart disease risk information, encouragement, and physical activity among Mexican-origin couples: Self- or spouse-driven change?

Family health history is an accessible, clinically-recommended genomic tool that improves health risk evaluation. It captures both genetic and modifiable risk factors that cluster within families. Thus, families represent a salient context for family health history-based interventions that motivate engagement in risk-reducing behaviors. While previous research has explored how individuals respond to their personal risk information, we extend this inquiry to consider how individuals respond to their spouse's risk information among a sample of Mexican-Americans. One hundred and sixty spouse-dyads within Mexican-heritage households received a pedigree or a pedigree and personalized risk assessments, with or without behavioral recommendations. Analyses of Covariance (ANCOVAs) were conducted to assess the relationship between risk feedback, both personal and spouse, and self-reported physical activity levels at 3-month and 10-month assessments, controlling for baseline levels. The effect of being identified as an encourager of spouse's healthy weight was also evaluated. Personal feedback had no effect on participants' physical activity at either 3- or 10-month assessments. However, husbands' risk information was associated with wives' physical activity levels at 3-month assessment, with women whose husbands received both increased risk feedback and behavioral recommendations engaging in significantly higher physical activity levels than all other women. At 10-month follow-up, physical activity levels for both husbands and wives differed depending on whether they encouraged their spouse's healthy weight. Spousal risk information may be a stronger source of motivation to improve physical activity patterns than personal risk information, particularly for women. Interventions that activate interpersonal encouragement among spouses may more successfully extend intervention effects.

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.