Schott J, Buricke B, Buricke F
Zentralbl Gynakol. 1979;101(10):656-65.
A record was taken 1973 of 22,466 single and 3,287 multiple live births, with premature deliveries being subdivided by age, birth order, coverture, and vocational backgrounds of the mothers concerned. The distributions thus established have produced evidence to the effect that all the above factors may have an impact upon premature delivery. Yet, multiple births were found to distort the distributions of all parameters used. --- Reference is made to possible interpretations of such studies in terms of large-scale trends, resources, risk hypotheses, and clusters, with examples being proposed for the latter.
1973年记录了22466例单胎活产和3287例多胎活产情况,早产按母亲年龄、生育顺序、婚姻状况及职业背景进行细分。由此确定的分布情况表明,上述所有因素可能对早产有影响。然而,发现多胎分娩会使所使用的所有参数的分布情况发生扭曲。——文中提到了根据大规模趋势、资源、风险假设和聚集情况对这类研究的可能解释,并为后者提出了示例。