Completing a National Birth Cohort in the United States.

Opinion VIEWPOINT Anne W. Riley, PhD Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland. Greg J. Duncan, PhD School of Education, University of California–Irvine. Corresponding Author: Anne W. Riley, PhD, Department of Population, Family, and Reproductive Health, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Office E4539, Baltimore, MD 21205 (ariley1@jhu.edu). jamapediatrics.com Completing a National Birth Cohort in the United States Not only is life expectancy in the United States shorter than in other high-income nations, but the US popula- tion also ranks comparatively worse across 9 key health areas: (1) infant mortality and low birth weight; (2) injuries and homicides; (3) adolescent pregnancy and sexually transmitted infections; (4) human immu- nodeficiency virus and AIDS; (5) drug-related deaths; (6) obesity and diabetes; (7) heart disease; (8) chronic lung disease; and (9) disability. 1 Unfortunately, policy makers and the health community lack a complete ex- planation for the US health disadvantage. Researchers know that persistent racial, ethnic, socioeconomic, and geographic disparities in health are part of the explana- tion, but they do not fully understand them or know how best to address them. 2 Especially in a country as increas- ingly diverse as the United States and during a time when the social environment is rapidly changing as a result of digital technologies, it is crucial to fully understand how factors, such as geographic location and family, social, economic, physical, nutritional, and community envi- ronments, produce disparate health outcomes. In the late 1990s, scientists and researchers throughout the United States highlighted the need for information that ultimately would lead to improve- ments in the health, development, and well-being of chil- dren. This led to the creation of the National Children’s Study (NCS) through the National Children’s Health Act of 2000. The NCS was designed as a birth cohort study to follow up a nationally representative birth cohort of 100 000 children until the age of 21 years. The NCS was to be a definitive study of children’s health. However, in the wake of criticisms of the study’s management in the National Research Council/Institute of Medicine report 3 and the assessment by a National Institutes of Health (NIH) advisory committee to the director that the plans for the study were not feasible, 4 the study was can- celled in December 2014. To identify whether a US longitudinal birth cohort study is still needed and, if so, to suggest methods for its design and implementation, 2 expert meetings were convened in 2016 by the National Academies of Sci- ences, Engineering, and Medicine, with funding from the Robert Wood Johnson Foundation. In these meetings, a group of 16 experts from academia, philanthropy, in- dustry, and government discussed current NIH initia- tives to understand children’s health and develop- ment, the weaknesses of the NCS, and the questions of whether a national birth cohort study is still needed and feasible. The experts also considered whether the stud- ies that are now planned by the NIH in lieu of the NCS are capable of providing comprehensive explanations for the relatively poor health of the US population. A synthesis of the group’s discussions and conclusions was published on May 31 as part of the National Acad- emy of Medicine Perspectives series (http://nam.edu /LifelongHealth). 5,6 The series’ articles contend that a nationally repre- sentative birth cohort study—beginning in the prenatal stage and following up children into adulthood—is not only feasible but remains crucial to building effective US health policy. Although selective cohort or cross- sectional studies are certainly less expensive to imple- ment, they cannot provide the more comprehensive un- derstanding of the effects of the family, social, economic, physical, nutritional, and community environments on health that is needed. These kinds of studies are lim- ited in that they only examine populations in specific lo- cations that do not represent the diversity of the United States, focus on a small number of factors, or involve a limited period of human development. Therefore, they will not allow for an understanding of the full comple- ment of environmental and social factors that interact to affect health over the life course. To remedy some of these issues, the NIH has begun a new effort, the Environmental Influences on Child Health Outcomes (ECHO) Study. The ECHO Study is proposed to be a collection of existing cohort studies. By merging existing cohorts, the ECHO Study will have increased statistical power to detect associations between the environment and health when compared with a single cohort. However, given that the ECHO cohorts were not designed to be merged, they cannot provide data that generalize to the full range of diverse population subgroups and geographic locations in the United States. In contrast, studies based on a national probability sampling frame can support the kinds of generalizable statistical inferences that are crucial for understanding how children grow into healthy adults and live up to their full developmental potential across all of the variations in social, physical, nutritional, and chemical exposures. They also provide a much stronger basis for health policy formulation than results from studies that do not represent diversity across the United States. The research community has learned much about the conduct of birth cohort studies from a decade of planning for the NCS, from the approximately 6000 NCS Vanguard Study families who participated, and from other birth cohort studies in the United States and abroad. It will be feasible, efficient, and cost-effective to conduct a new national birth cohort study from the pre- natal period to adulthood if researchers adhere to the following principles: • A hospital/birth center–based sampling frame and re- cruitment of pregnant participants through sampled settings that represent clinicians across the nation. (Reprinted) JAMA Pediatrics September 2016 Volume 170, Number 9 Copyright 2016 American Medical Association. All rights reserved. Downloaded From: http://jamanetwork.com/ by a University of California - Irvine User on 11/20/2016