Accounting for length-bias and selection effects in estimating the distribution of menstrual cycle length.

ABSTRACT: 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 le

SUBMITTER: Lum KJ 

PROVIDER: S-EPMC4263226 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature