Estimating Trajectories of Energy Intake Through Childhood and Adolescence Using Linear-Spline Multilevel Models
Estimating Trajectories of Energy Intake Through Childhood and Adolescence Using Linear-Spline Multilevel Models
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DOI：
10.1097/ede.0b013e318295af33
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发表时间：
2013-07-01
期刊：
影响因子：
5.4
通讯作者：
Howe, Laura D.
中科院分区：
文献类型：
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作者：
Anderson, Emma L.;Tilling, Kate;Howe, Laura D.
背景：在整个生命courses.Methods的饮食摄入量的变化的评估方法：我们演示了使用线性样条多层次模型，总结通过儿童和青少年的能量摄入轨迹和他们的应用程序作为曝光，结果，或介质。雅芳家长和儿童纵向研究使用食物频率问卷（FFQ）和3天食物日记多次评估3至13岁儿童的饮食摄入量。我们使用线性样条多水平模型估计了12,032名儿童的能量摄入轨迹。然后，我们评估了这些轨迹与母亲的身体质量指数（BMI），后来的后代BMI，以及他们的作用，在调解母亲和后代BMIs.Results之间的关系：模型估计平均和个人的能量摄入量在3年，从3岁到7岁，从7岁到13岁的能量摄入量的线性变化。通过将暴露（在这个例子中，母亲的BMI）包括在多水平模型中，我们能够估计暴露水平之间的平均能量摄入轨迹。当能量摄入轨迹是后来结果的暴露（在这种情况下，后代BMI）或中介（母亲和后代BMI之间）时，结果是相似的，无论是使用两步过程（从多水平模型导出个体水平截距和斜率，并将其用于线性回归/路径分析），还是单步过程（多变量多水平模型）。轨迹是相似的FFQs和食物日记进行评估时，无论是单独的，或合并成一个model.Conclusions：线性样条多层次模型提供了有用的总结轨迹的饮食摄入量，可以用作曝光，结果，或调解人。
Background:Methods for the assessment of changes in dietary intake across the life course are underdeveloped.Methods:We demonstrate the use of linear-spline multilevel models to summarize energy-intake trajectories through childhood and adolescence and their application as exposures, outcomes, or mediators. The Avon Longitudinal Study of Parents and Children assessed children's dietary intake several times between ages 3 and 13 years, using both food frequency questionnaires (FFQs) and 3-day food diaries. We estimated energy-intake trajectories for 12,032 children using linear-spline multilevel models. We then assessed the associations of these trajectories with maternal body mass index (BMI), and later offspring BMI, and also their role in mediating the relation between maternal and offspring BMIs.Results:Models estimated average and individual energy intake at 3 years, and linear changes in energy intake from age 3 to 7 years and from age 7 to 13 years. By including the exposure (in this example, maternal BMI) in the multilevel model, we were able to estimate the average energy-intake trajectories across levels of the exposure. When energy-intake trajectories are the exposure for a later outcome (in this case offspring BMI) or a mediator (between maternal and offspring BMI), results were similar, whether using a two-step process (exporting individual-level intercepts and slopes from multilevel models and using these in linear regression/path analysis), or a single-step process (multivariate multilevel models). Trajectories were similar when FFQs and food diaries were assessed either separately, or when combined into one model.Conclusions:Linear-spline multilevel models provide useful summaries of trajectories of dietary intake that can be used as an exposure, outcome, or mediator.