As we outlined in the previous paper in this series, our nation needs foundational data in order to understand how social, physical, chemical, and nutritional environments interact to impact how Americans grow, live, and prosper. To satisfy this need, we propose a nationally representative birth cohort study beginning in the prenatal period and following the children through adulthood. Existing research efforts are inadequate because their data are not sufficiently comprehensive and representative to identify both positive and negative factors affecting children’s health or to fully understand health inequities in the United States.
A crucial element of the proposed study is a well-designed national probability sample from which conclusions can be drawn to the larger population from which the sample was randomly selected. In contrast, self-selection sampling consists of volunteers who elected to be part of a study. This technique introduces self-selection bias and can lead to a sample that is not representative of the population being studied. In fact, a report by the National Research Council and the Institute of Medicine, The National Children’s Study 2014: An Assessment, endorsed a probability sample design for a future national longitudinal birth cohort study. In this paper, we provide an overview of a feasible sample design, methods for stakeholder engagement, tools for data collection, and approaches for providing access to the data that would maximize its value.