Birth weight and mortality: Causality or confounding?
Birth weight and mortality: Causality or confounding?
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DOI：
10.1093/aje/kwj237
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发表时间：
2006-08-15
影响因子：
5
通讯作者：
Weinberg, Clarice R.
中科院分区：
文献类型：
--
作者：
Basso, Olga;Wilcox, Allen J.;Weinberg, Clarice R.
出生体重和死亡率之间的关联是流行病学中最强的关联之一。虽然早产会导致小婴儿和高死亡率，但这并不能解释这种联系。也有人提出了限制胎儿生长的建议，尽管它的特点尚不清楚，因为它缺乏一个独立于体重的定义。如果像一些假设那样，出生体重本身并不是导致死亡的原因，那么它与死亡率的关系将不得不通过降低出生体重和增加死亡率的混合因素来解释。在这篇论文中，作者探索了这些混杂因素所需的特征，以实现观察到的出生体重和死亡率之间的关联。通过一个简单的模拟，他们发现，观察到的足月小婴儿风险陡峭的梯度可能是由一种或多种罕见的条件(总患病率为0.5%)造成的，这种情况对胎儿生长(-1.7标准差)和死亡率(相对风险=160)都有深远的影响。候选条件可能包括畸形、胎儿或胎盘非整倍体、感染或印记障碍。如果这种罕见的因素是出生体重与死亡率之间的联系的基础，这将对胎儿生长受限和出生体重的研究以及预防婴儿死亡具有广泛的意义。
The association between birth weight and mortality is among the strongest seen in epidemiology. While preterm delivery causes both small babies and high mortality, it does not explain this association. Fetal growth restriction has also been proposed, although its features are unclear because it lacks a definition independent of weight. If, as some postulate, birth weight is not itself on the causal path to mortality, its relation with mortality would have to be explained by confounding factors that decrease birth weight and increase mortality. In this paper, the authors explore the characteristics such confounders would require in order to achieve the observed association between birth weight and mortality. Through a simple simulation, they found that the observed steep gradient of risk for small babies at term can be produced by a rare condition or conditions (with a total prevalence of 0.5%) having profound effects on both fetal growth (-1.7 standard deviations) and mortality (relative risk = 160). Candidate conditions might include malformations, fetal or placental aneuploidy, infections, or imprinting disorders. If such rare factors underlie the association of birth weight with mortality, it would have broad implications for the study of fetal growth restriction and birth weight, and for the prevention of infant mortality.