39 Pooling biospecimens for exposure assessment for case-cohort analyses in cohort studies

Oregon Convention Center 

For case-control studies that assess risk from expensive-to-measure exposures like dioxin, mixing together ("pooling") biospecimens from sets of participants before assay saves money and conserves biospecimens. Large cohort studies can reduce assay costs through case-cohort analyses, where specimens from a random sample of all cohort participants, called the "subcohort", plus a random sample of cases not in the subcohort are assayed. Use of pooling for case-cohort analyses promises further savings but remains unstudied. This paper develops and evaluates a pooling strategy and a corresponding data-analysis method for using biospecimen pooling for case-cohort analyses in large cohort studies that relate biospecimen-based exposure measures to risk of disease. Our proposed strategy constructs pooling sets for cases not in the subcohort after grouping them according to time of diagnosis, and constructs pooling sets separately for members of the subcohort, grouping them on age at entry. We performed simulation studies to evaluate the performance of our approach for for cohorts and subcohorts of various sizes.

pooling

case-cohort study

cohort study 

Section on Statistics in Epidemiology