Gage Timothy B.
Department of Anthropology and Department of Epidemiology, University at Albany, State University of New York, Albany, New York.
Am J Hum Biol. 2000 Mar;12(2):181-191. doi: 10.1002/(SICI)1520-6300(200003/04)12:2<181::AID-AJHB3>3.0.CO;2-0.
As an antecedent of birthweight and in its own right, gestational age is an important proximate determinant of infant mortality. Recent analyses using mixture models of birthweight distributions suggest that substantial heterogeneity occurs within a birth cohort even when controlling for sex and ethnicity. This article extends the mixture model analysis to gestational age. The results indicate that, like birthweight, human gestational age distributions are heterogeneous, consisting of two, or perhaps more, subpopulations with separate means and variances. The possibility that birthweight and gestational age both identify the same underlying subpopulations cannot be rejected. Statistical analyses of the sex and ethnic differences indicate that, like birthweight, gestational age distributions vary significantly between the sexes and among ethnic groups. However, the pattern, and even the direction, of the variation often differs between the two indicators of birth outcome. The results suggest that a multivariate mixture model that combines birthweight and gestational age might be a useful extension of the univariate mixture models. Am. J. Hum. Biol. 12:181-191, 2000. Copyright 2000 Wiley-Liss, Inc.
作为出生体重的一个先决因素，并且就其本身而言，胎龄是婴儿死亡率的一个重要直接决定因素。最近使用出生体重分布混合模型的分析表明，即使在控制了性别和种族之后，出生队列中仍存在很大的异质性。本文将混合模型分析扩展到胎龄。结果表明，与出生体重一样，人类胎龄分布也是异质的，由两个或可能更多具有不同均值和方差的亚群组成。不能排除出生体重和胎龄都识别相同潜在亚群的可能性。对性别和种族差异的统计分析表明，与出生体重一样，胎龄分布在性别之间和种族群体之间存在显著差异。然而，出生结局的这两个指标之间的变化模式甚至方向往往不同。结果表明，结合出生体重和胎龄的多变量混合模型可能是单变量混合模型的一个有用扩展。《美国人类生物学杂志》12:181 - 191，2000年。版权所有2000年威利 - 利斯公司。
