Dynamic and Static Correlates of Adolescent Physical Activity: A Latent Trajectory Analysis

<p>BACKGROUND: Adolescence is a critical period for the study of physical activity as significant declines are often reported throughout the adolescent years. The reduction in physical activity is of great concern, due to its strong association with increasing levels of obesity among today’s youth. Understanding the trajectory of change in physical activity and the influences of change has potential for informing future interventions and policy. </p><p>PURPOSE: The purpose of this research was to examine trajectories of physical activity across adolescence and then compare correlates derived from Sallis’ framework (demographics, self-efficacy, screen time and peer support). The correlates were examined as baseline predictors as well as potential dynamic factors, examining how change in influential factors may be simultaneously associated with changes in physical activity. </p><p>METHODS: The data are derived from a school-based behavioral intervention trial involving an ethnically diverse sample of 1543 seventh graders from three urban schools in the Midwest. Latent trajectory models were used to model individual developmental change in physical activity, as well as dynamic correlates across adolescence. These models were then combined to compare the changes in correlates with the changes in physical activity. </p><p>RESULTS: While the change in the group mean for physical activity was small, the latent trajectory analyses revealed significant individual change over time. Age, gender and race were each found to be associated with these trajectories. All hypothesized dynamic correlates (i.e., self-efficacy, screen time) were also found to change across time; however, only the trajectories of self-efficacy and peer support were simultaneously associated with changes in physical activity. </p><p>CONCLUSIONS: The unique and dynamic changes in both physical activity and its correlates in adolescence underscore the importance of studying them longitudinally. Further, latent trajectory analyses produce richer results than group level analyses due to studying the individual differences. Children who establish patterns of high physical activity are more likely to retain these patterns through adolescence. However, developmental changes in perceived efficacy and peer behavior clearly play a strong role as well. This study can inform both family and school practices by establishing regular opportunities for physical activity in the years leading up to adolescence.</p>

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Epidemiology and Biostatistics

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Charvat, Jacqueline M.

Contributors dc:contributor

• Borawski, Elaine

• Epidemiology
• physical activity
• adolescents
• longitudinal
• latent trajectory modeling

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1355503803

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1355503803