Timing and mechanism for developing physical activity habits

描述（由申请人提供）：习惯性体力活动（PA）为儿童和青少年提供了许多健康益处。平均PA水平在青春期大幅下降，这会影响长期的健康状况和医疗保健费用。一些研究表明，PA行为可能是在不同的时间和不同的模式建立的儿童亚组。研究还检查了PA行为改变的决定因素。然而，大多数研究的分析方法并没有恰当地捕捉到假设影响PA行为的多个生物社会因素之间的复杂关系。知识差距和方法上的挑战可以通过一种创新的分析方法来解决，如潜在的阶级成长分析和潜在变量分析。本项目的目标是了解整个童年时期PA行为的发展以及PA发展的生物社会影响。我们假设，儿童PA行为的发展的特点是多个发展途径，代表不同群体的儿童人口。我们还假设，有潜在的生物社会特征，占PA的变化模式在童年和成年早期。为了检验这些假设，我们建议使用来自爱荷华州骨发育研究数据库的纵向数据库进行二次数据分析。该项目的三个具体目标是AMI 1）确定5至19岁MVPA行为的发展轨迹，AIM 2）确定与AIM 1中确定的MVPA行为的不同发展轨迹相关的生物社会特征，以及AIM 3）确定总体PA和久坐时间的轨迹，并确定其相关的生物社会特征。我们将使用潜在的类增长分析，以确定多个发展轨迹的PA。我们还将使用潜变量的方法来表征亚群遵循一定的PA轨迹。这项研究将扩大知识的模式和决定因素的PA行为。该项目的成功将加速在儿科PA研究中使用创新的潜在类方法。

DESCRIPTION (provided by applicant): Habitual physical activity (PA) provides numerous health benefits for children and adolescents. Average PA levels substantially decrease during adolescence, which influences long-term health conditions and healthcare costs. A few studies have suggested that PA behavior may be established in different times and in different patterns by child subgroups. Studies have also examined the determinant of PA behavior change. However, the analytic approach of the most studies has not appropriately captured the complex relationship among multiple bio-social factors hypothesized to affect PA behavior. The knowledge gap and methodological challenge can be addressed using an innovative analytic approach such as latent class growth analysis and latent variable analysis the objective of this project is to understand the development of PA behavior throughout childhood and bio- social influences of the PA development. We hypothesize that the development of child PA behavior is characterized by multiple developmental pathways representing distinct groups within the child population. We also hypothesize that there are underlying bio-social characteristics that account for PA change patterns during childhood and early adulthood. To test these hypotheses, we propose to conduct secondary data analysis using the longitudinal database from the Iowa Bone Development Study database. The three specific aims of this project are AMI 1) to determine developmental trajectories of MVPA behavior from age 5 to 19 years, AIM 2) to identify bio-social characteristics associated with different developmental trajectories of MVPA behavior identified in AIM 1, and AIM 3) to determine the trajectories for overall PA and sedentary time, and identify their associated bio-social characteristics. We will use latent class growth analysis to identify multiple developmental trajectories of PA. We will also use a latent variable approach to characterize the subpopulations following a certain PA trajectories. This study will expand knowledge on patterns and determinants of PA behavior. The success of this project will accelerate the use of the innovative latent class methodology in pediatric PA research.