Bias due to left truncation and left censoring in longitudinal studies of developmental and disease processes.

ABSTRACT: In longitudinal studies of developmental and disease processes, participants are followed prospectively with intermediate milestones identified as they occur. Frequently, studies enroll participants over a range of ages including ages at which some participants' milestones have already passed. Ages at milestones that occur prior to study entry are left censored if individuals are enrolled in the study or left truncated if they are not. The authors examined the bias incurred by ignoring these issues when estimating the distribution of age at milestones or the time between 2 milestones. Methods that account for left truncation and censoring are considered. Data on the menopausal transition are used to illustrate the problem. Simulations show that bias can be substantial and that standard err

SUBMITTER: Cain KC 

PROVIDER: S-EPMC3121224 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature