Carrie D. Heitzler

Influence of limit-setting and participation in physical activity on youth screen time.

OBJECTIVES: To examine the associations of demographics, rules associated with television-viewing, and physical activity with daily screen time (including television, non–school-related computer use, and video games) in children and adolescents. METHODS: We analyzed data from a telephone survey of 7415 youth aged 9 to 15 years from the Youth Media Campaign Longitudinal Survey. We used logistic regression models to calculate odds of exceeding recommended screen-time limits (>120 minutes/day) according to demographics, rules, and physical activity. RESULTS: Odds that children would exceed recommended screen-time limits were positively associated with age and black race/ethnicity and negatively associated with income level. Children and adolescents who reported that they really agreed that their parents had rules about time spent watching television and playing video games were less likely to exceed recommended limits than those who strongly disagreed that their parents had rules. Similarly, when parents reported always or very often having limits on television watching (versus rarely or never) and when parents correctly identified the recommended limits, children were less likely to exceed recommended limits. Children whose parents reported consistent limits and who themselves reported consistent rules about time spent watching television had the lowest prevalence of exceeding recommended limits. Odds that children would exceed recommended limits decreased as physical activity in the previous week increased. CONCLUSIONS: Parental rules regarding screen time and participation in physical activity play a role in the amount of screen time among children and adolescents. Programs that encourage limit-setting by parents and promote physical activity may reduce screen time among youth.

Testing a hierarchy-of-effects model: pathways from awareness to outcomes in the VERB campaign 2002-2003.

BACKGROUND The McGuire hierarchy-of-effects (HOE) model, used extensively in mass-media interventions to describe the mechanisms for understanding effects, has not been tested in physical activity campaigns. DESIGN Data collected at baseline (2002) and follow-up (2003) surveys in the VERB evaluation were used in structural equation modeling to test pathways and hierarchies of campaign effects. SETTING/PARTICIPANTS Population-based cohort of youth aged 9-13 years (N=2364) for whom complete baseline and follow-up data were available. MAIN OUTCOME MEASURES Awareness of the VERB campaign, understanding of the VERB message, attitude toward being active, outcome expectations, and physical activity participation. RESULTS Among youth aged 9-13 years (tweens) in the study cohort, significant paths were identified between awareness and understanding (0.72, p<0.001) and between understanding and being physically active (0.11, p<0.05). At baseline there was a high prevalence of positive attitudes and outcome expectations, and these were not influenced by change in understanding or awareness. Among inactive tweens only, the same paths were identified except that, in this subgroup, attitude was related to physical activity (0.13, p<0.05), and awareness was more strongly related to physical activity than it was for the whole sample (0.14, p<0.01). CONCLUSIONS These findings provided limited support for the HOE model and suggest that increased awareness and understanding were the key proximal effects that led to behavior change. A distinct sequence of effects, which bypassed attitudes and outcome expectations, was found for these U.S. young people. The findings could inform the design of future campaigns to address youth physical activity.

Evaluating a model of youth physical activity.

OBJECTIVE To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. METHODS Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a sample of youth aged 10-17 years (N = 720). RESULTS Peer support, parent physical activity, and perceived barriers were directly related to youth activity. The proposed model accounted for 14.7% of the variance in physical activity. CONCLUSIONS The results demonstrate a need to further explore additional individual, social, and environmental factors that may influence youths regular participation in physical activity.

Overview of Formative, Process, and Outcome Evaluation Methods Used in the VERB™ Campaign

Evaluation was an integral part of the VERB campaign. This paper describes the array of evaluation methods used to support the development, implementation, and assessment of campaign activities. The evaluation of VERB consisted of formative, process, and outcome evaluations and involved both qualitative and quantitative methods. Formative evaluation allowed staff to test ideas for messages and to gauge their appropriateness for the intended audiences. Process evaluation allowed staff to test and monitor the fidelity of the campaigns implementation to objectives and to make changes while the campaign was under way. Outcome evaluation allowed staff to determine the campaigns effects on the target audience. Because a comprehensive approach was used, which included formative and process evaluation, the VERB teams ability to interpret the results of the outcome evaluation was enhanced.

Bringing “Play” to Life: The Use of Experiential Marketing in the VERB™ Campaign

Given the abundance of advertising and media that children and adolescents are exposed to today, it is increasingly important to incorporate nontraditional channels and venues in strategies designed to reach them. One such channel that the CDCs VERB campaign employed was experiential marketing, which is defined here as a live event or experience that gives the target audience the opportunity to see a product and experience it for themselves. Experiential marketing and the tactics that the VERB campaign used to reach children aged 9-13 years (tweens) with health messages about physical activity are described, including a discussion about how other public health campaigns might use experiential marketing and other commercial marketing techniques to reach the public with public health messages.

Association of the home environment with cardiovascular and metabolic biomarkers in youth

OBJECTIVE To examine the relationship between the home environment and biomarkers associated with the cardiovascular and metabolic risks in adolescents. METHODS Three hundred fifty-eight adolescents (185 males and 173 females) living in the Twin Cities Metropolitan Area, Minnesota, between the ages of 10-17 years agreed to participate. Data were collected from August 2006 through March 2008. A fasting blood sample was drawn and assayed for insulin, glucose and lipids. Resting blood pressure, percent body fat (PBF) and body mass index were also measured. The home environment was assessed using a self-report of physical activity (PA) and media inventory (PAMI) completed by the parents. Density of PA and media equipment was calculated by summing the number of items present in the home and dividing by the total number of locations in the home. PA and screen media density were modeled as independent variables. RESULTS Our results found that the density of PA equipment was negatively associated with insulin levels, low-density lipoprotein (LDL), total cholesterol, insulin resistance, and PBF. Media density was positively associated with insulin, LDL, total cholesterol, and PBF. CONCLUSIONS The results of this study suggest that the home environment is associated with metabolic and cardiovascular health in adolescents.