Current status of the National Children's Study.

The commentary by David Savitz and Roberta Ness reflects their interest in public health research and their perspective as former investigators in the National Children’s Study. However, the National Institutes of Health (NIH) has made substantive changes in the design, operations, and governance of the National Children’s Study beginning in the third quarter of 2009, which represent a departure from prior practice. We therefore welcome the opportunity to outline some of the major new strategic initiatives. The National Children’s Study is an unprecedented project that will follow a cohort of children from before birth to 21 years of age to examine relationships among the environment (broadly defined), genetics, growth, development, and health. What makes the study unique is the goal of collecting numerous environmental samples and biospecimens, as well as a wide range of anthropometric, behavioral, dietary, and health data (initially from mothers and then from their children). Experience from other studies can be useful to frame the parameters of this study, but the most reliable method for designing and implementing a public project of such scope and complexity is to be as data-driven and evidence-based as possible. Following the recommendations of a National Academy of Sciences review panel, a pilot or “Vanguard Phase” was instituted in January 2009 with 2 locations, and then expanded the pilot to 5 additional locations by April 2009. By August 2009, pilot data indicated that the original study assumptions regarding the prevalence of pregnant women (and women likely to become pregnant, based on a screening instrument) were overly optimistic. In addition, the rate of identified pregnant women who consented to participate in the study, although a respectable 60%, was less than the 75% initially projected. On the basis of these early data, the overall efficiency of recruitment would have resulted in a prolonged recruitment phase with excessive costs. Consequently, the Vanguard Study protocol was rewritten to emphasize the operational aspects of the feasibility, acceptability, and costs of recruitment, logistics, and study visit assessments. The recruitment assumptions were re-evaluated and 3 alternate recruitment strategies were designed. These strategies are based on experience from published studies, expert advice, consultations with other federal agencies that have programs in demographic research or public-health surveys, and input from the multiple oversight bodies of the National Children’s Study. The strategies are as follows: (1) an enhanced household recruitment approach; (2) a provider-based approach; and (3) a 2-tier, high-intensity/low-intensity approach. Each recruitment strategy will be deployed in 10 locations for a total of 30 new locations, and will receive approximately equal resources to examine their potential efficiencies, limitations, logistics, and costs. The provider-based approach reflects the “point-of-care” recruitment strategy raised by Savitz and Ness. We agree that this recruitment strategy has potential strengths, but we feel it must be tested empirically