Modeling effects of age at and time since delivery on subsequent risk of cancer
Modeling effects of age at and time since delivery on subsequent risk of cancer
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DOI：
10.1097/00001648-199911000-00015
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发表时间：
1999-11-01
期刊：
影响因子：
5.4
通讯作者：
Kvåle, G
中科院分区：
文献类型：
--
作者：
Heuch, I;Albrektsen, G;Kvåle, G
我们描述了一个简单的模型来检验分娩对癌症风险的时间效应，考虑了来自队列或病例对照研究设计的单产和未分娩妇女的数据。对于单产妇女，风险的表达包括分娩时的年龄和分娩后的时间。由于对单胎的影响有了适当的定义，未分娩的妇女不需要与分娩有关的术语。如果假设纯年龄效应在所有妇女中都是相同的，那么分娩年龄和分娩开始时间的影响都是可估量的，尽管单产妇女的年龄与达到年龄呈线性相关。省略自分娩以来的时间，并考虑到单一生育年龄特定影响的异质性，提供了对自分娩以来的时间影响的有效检验，尽管风险估计是有偏见的。在最近的病例对照研究中，基于分娩年龄和达到年龄的线性交互作用项的检验不适合于调查分娩后时间的影响。我们展示了我们的基本模型如何应用于挪威一项乳腺癌研究的病例对照数据分析。然后我们将这些结果与其他模型的结果进行比较。
We describe a simple model for examining the temporal effects of childbirth on cancer risk, considering data on uniparous and nulliparous women, from either a cohort or case-control study design. For uniparous women, the expression for risk includes terms for age at delivery and time since delivery. With a suitable definition of the effect of uniparity, no terms relating to delivery are needed for nulliparous women. If the pure age effect is assumed to be the same in all women, the effects of age at delivery and time since delivery are both estimable, despite the linear dependence involving attained age in uniparous women. Omitting terms for time since delivery and considering the heterogeneity of age-specific effects of uniparity provides a valid test for the effect of time since delivery, although risk estimates are biased. Tests based on linear interaction terms for age at delivery and attained age, as applied in recent case-control studies, are not appropriate for investigating the effect of time since delivery. We show how our basic model may be applied to the analysis of case-control data from a Norwegian study of breast cancer. We then compare these results with those from other models.