From the Department of Public Health, Erasmus University Medical Centre Rotterdam, Rotterdam, The Netherlands.
Department of Public Administration and Sociology, Erasmus University Rotterdam, Rotterdam, The Netherlands.
Epidemiology. 2020 Jul;31(4):578-586. doi: 10.1097/EDE.0000000000001210.
We investigated to what extent social inequalities in childhood obesity could be reduced by eliminating differences in screen media exposure.
We used longitudinal data from the UK-wide Millennium Cohort Study (n = 11,413). The study measured mother's educational level at child's age 5. We calculated screen media exposure as a combination of television viewing and computer use at ages 7 and 11. We derived obesity at age 14 from anthropometric measures. We estimated a counterfactual disparity measure of the unmediated association between mother's education and obesity by fitting an inverse probability-weighted marginal structural model, adjusting for mediator-outcome confounders.
Compared with children of mothers with a university degree, children of mothers with education to age 16 were 1.9 (95% confidence interval [CI] = 1.5, 2.3) times as likely to be obese. Those whose mothers had no qualifications were 2.0 (95% CI = 1.5, 2.5) times as likely to be obese. Compared with mothers with university qualifications, the estimated counterfactual disparity in obesity at age 14, if educational differences in screen media exposure at age 7 and 11 were eliminated, was 1.8 (95% CI = 1.4, 2.2) for mothers with education to age 16 and 1.8 (95% CI = 1.4, 2.4) for mothers with no qualifications on the risk ratio scale. Hence, relative inequalities in childhood obesity would reduce by 13% (95% CI = 1%, 26%) and 17% (95% CI = 1%, 33%). Estimated reductions on the risk difference scale (absolute inequalities) were of similar magnitude.
Our findings are consistent with the hypothesis that social inequalities in screen media exposure contribute substantially to social inequalities in childhood obesity.
本研究旨在探究消除屏幕媒体暴露差异在多大程度上可以减少儿童肥胖的社会不平等。
我们使用了来自英国全国家庭纵向研究（n=11413）的纵向数据。研究在儿童 5 岁时测量了母亲的教育水平。我们将屏幕媒体暴露定义为 7 岁和 11 岁时的电视观看和计算机使用的综合。我们通过人体测量指标来确定 14 岁时的肥胖情况。我们通过拟合逆概率加权边际结构模型来估计母亲教育与肥胖之间无中介关联的反事实差异度量，同时调整了中介-结果混杂因素。
与母亲受过大学教育的孩子相比，母亲仅受过 16 年教育的孩子肥胖的可能性高 1.9 倍（95%置信区间[CI] = 1.5，2.3），而母亲未受过任何教育的孩子肥胖的可能性高 2.0 倍（95% CI = 1.5，2.5）。如果消除 7 岁和 11 岁时屏幕媒体暴露的教育差异，与受过大学教育的母亲相比，在 14 岁时肥胖的估计反事实差异在母亲接受 16 年教育时为 1.8（95% CI = 1.4，2.2），母亲未受过任何教育时为 1.8（95% CI = 1.4，2.4），在风险比尺度上，相对儿童肥胖不平等程度将降低 13%（95% CI = 1%，26%）和 17%（95% CI = 1%，33%）。风险差尺度（绝对不平等）上的估计减少量也具有相似的幅度。
我们的发现与假设一致，即屏幕媒体暴露的社会不平等在很大程度上导致了儿童肥胖的社会不平等。
