Accounting for length-bias and selection effects in estimating the distribution of menstrual cycle length.
Accounting for length-bias and selection effects in estimating the distribution of menstrual cycle length.
复制标题
在估计月经周期长度分布时考虑长度偏差和选择效应。
DOI：
10.1093/biostatistics/kxu035
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Louis,ThomasA
中科院分区：
文献类型：
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作者：
Lum,KirstenJ;Sundaram,Rajeshwari;Louis,ThomasA
前瞻性妊娠研究是月经周期长度纵向数据的宝贵来源。然而，在推断此类更新过程时需要小心。例如，考虑抽样计划对于对研究人群的月经周期长度分布进行无偏估计是必要的。如果夫妇在得知这项研究后就可以报名，而不是等待新的月经周期开始，那么由于长度偏差，报名周期将随机大于一般周期，这是流行队列研究的典型特征。此外，登记的概率可能取决于女性自末次月经以来的时间长度（向后复发时间），从而产生选择效应。我们专注于考虑登记月经周期长度可能性中的长度偏差和选择效应，使用递归两阶段方法，其中我们首先估计登记概率作为向后递归时间的函数，然后将其用于考虑长度偏差和选择效应的抽样权重的可能性。为了扩大我们方法的适用性，我们增强了我们的模型，以纳入特定于夫妇的随机效应和与时间无关的协变量。当适当考虑抽样计划特征时，模拟研究量化了两种注册概率场景的性能。此外，我们还估计了生育力纵向调查和环境研究的研究人群的入组概率和月经周期长度的分布。
Prospective pregnancy studies are a valuable source of longitudinal data on menstrual cycle length. However, care is needed when making inferences of such renewal processes. For example, accounting for the sampling plan is necessary for unbiased estimation of the menstrual cycle length distribution for the study population. If couples can enroll when they learn of the study as opposed to waiting for the start of a new menstrual cycle, then due to length-bias, the enrollment cycle will be stochastically larger than the general run of cycles, a typical property of prevalent cohort studies. Furthermore, the probability of enrollment can depend on the length of time since a woman’s last menstrual period (a backward recurrence time), resulting in selection effects. We focus on accounting for length-bias and selection effects in the likelihood for enrollment menstrual cycle length, using a recursive two-stage approach wherein we first estimate the probability of enrollment as a function of the backward recurrence time and then use it in a likelihood with sampling weights that account for length-bias and selection effects. To broaden the applicability of our methods, we augment our model to incorporate a couple-specific random effect and time-independent covariate. A simulation study quantifies performance for two scenarios of enrollment probability when proper account is taken of sampling plan features. In addition, we estimate the probability of enrollment and the distribution of menstrual cycle length for the study population of the Longitudinal Investigation of Fertility and the Environment Study.