Pooling Designs for Outcomes under a Gaussian Random Effects Model

• Published in: Biometrics Vol. 68; no. 1; pp. 45 - 52
• Main Authors: Malinovsky, Yaakov, Albert, Paul S., Schisterman, Enrique F.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.03.2012; Wiley-Blackwell; Blackwell Publishing Ltd
• Subjects: Bioassays; Biological markers; Biomarkers; Biomarkers - blood; BIOMETRIC METHODOLOGY; Biometrics; biometry; correlation; Covariance structure; Design analysis; Design efficiency; Design evaluation; epidemiological studies; Epidemiology; Estimators; F2-Isoprostanes - blood; Female; Humans; Intraclass correlation coefficient; Likelihood Functions; longitudinal studies; Maximum likelihood estimation; Maximum likelihood method; Menstrual Cycle - blood; Modeling; Normal Distribution; Outcome Assessment, Health Care - methods; Oxidative stress; Pooling; Premenopause; Random effects model; Statistical variance; Stress, Psychological - blood; Stress, Psychological - diagnosis; Stress, Psychological - epidemiology; Treatment Outcome; variance; women
• ISSN: 0006-341X; 1541-0420; 1541-0420
• DOI: 10.1111/j.1541-0420.2011.01673.x

Due to the rising cost of laboratory assays, it has become increasingly common in epidemiological studies to pool biospecimens. This is particularly true in longitudinal studies, where the cost of performing multiple assays over time can be prohibitive. In this article, we consider the problem of estimating the parameters of a Gaussian random effects model when the repeated outcome is subject to pooling. We consider different pooling designs for the efficient maximum likelihood estimation of variance components, with particular attention to estimating the intraclass correlation coefficient. We evaluate the efficiencies of different pooling design strategies using analytic and simulation study results. We examine the robustness of the designs to skewed distributions and consider unbalanced designs. The design methodology is illustrated with a longitudinal study of premenopausal women focusing on assessing the reproducibility of F2‐isoprostane, a biomarker of oxidative stress, over the menstrual cycle.