The NIH Congressional Justification (CJ) is part of the annual President’s Budget Request to Congress. It serves to provide House and Senate Appropriations Committees with a detailed estimate and justification for research and research support activities (for example, infrastructure, administrative costs, etc.) that the NIH anticipates funding in the coming fiscal year. Each of the 27 Institutes and Centers at the NIH, and the Office of the NIH Director, has a separate appropriation for which CJ documentation is prepared. Funding for the National Children’s Study falls within the Office of the Director appropriation.
Congressional Justification FY 2013
The National Children’s Study is a longitudinal birth cohort observational study with the overall goal to improve the health and well-being of children and to identify antecedents of healthy adulthood by examining the effects of a broad range of environmental influences and biological factors. The National Children’s Study will produce an unprecedented amount of pertinent information and provide a foundation to analyze factors that contribute to growth, development, health, and disease to guide science and policy.
In developing plans to implement this study, early architects of the National Children’s Study decided to aim for a sampling strategy that would deliver a national sample of children from birth through age 21 years. Thus, the sample frame for the Vanguard and Main Study was initially based on a national probability sample using geography as the basis. The initial sampling plan was to select approximately 100 of the about 3,000 counties in the United States as the Primary Sampling Units and smaller geographic segments within the Primary Sampling Units as Secondary Sampling Units. The initial recruitment plan was to have field workers go door to door to contact women living in a Secondary Sampling Unit who were either pregnant or between 18 and 49 and might become pregnant.
The Vanguard Study launched in January 2009 and, by summer 2009, field experience suggested that the household contact recruitment protocol in use would not allow the National Children’s Study to meet a target of 100,000 newborns in a reasonable time or at a reasonable cost. Thus, in 2010 the National Children’s Study began a substudy designed to compare alternative protocols for recruiting a population-based sample. In mid 2011, the National Children’s Study Program Office developed and discussed with the National Children’s Study Federal Advisory Committee and the NIH leadership assessing a sampling frame based on provider location instead of participant residence. By late 2011, the National Children’s Study had sufficient data to evaluate the recruitment strategies examined in the 2010 substudy. Preliminary analyses suggested that a provider-based recruitment strategy could be the most efficient, but with efficiency limited due to the segmented Secondary Sampling Units. Specifically, at a particular provider location, many women had to be screened to identify the relatively few who resided in a designated geographic segment.
In assessing alternative sampling strategies, National Children’s Study and NIH leadership considered the overall scientific goals and which of these could be achieved with different strategies. Additional considerations were costs, based on Vanguard data, and the reality of flat or shrinking budgets for biomedical research. As a consequence, NIH now proposes that the Main Study sampling frame be based on provider location. One approach for developing such a sampling frame would be to use providers associated with specific health plans. Such an approach would have several advantages in terms of cost and feasibility, but would abandon the geographic based probability sample. Consequently, the enrolled population would no longer be a national probability sample but, instead, a well described cohort followed longitudinally.
The specific consequence of the change in the sampling frame includes reduced precision in describing prevalence rates and generalizing some of the relationships observed. However, the National Children’s Study would still enroll a nationally varied sample. The loss of a probability sample will most affect the statistical generalizability of some relationships among psychosocial and economic parameters and outcomes. However, the capacity to study biological relationships and pathways will remain robust from a scientific standpoint, even if not statistically generalizable.
Next steps include:
- Work with National Children’s Study contractors, survey statisticians from the National Center for Health Statistics, biostatisticians from the National Institutes of Health, and additional statisticians from other federal agencies and the private sector to develop further this proposed approach, evaluate alternative parameters for the sampling strategy, and articulate the implications of the approach with respect to the generalizability of different types of findings.
- Conduct a feasibility study of the proposed provider-based sampling approach, and develop protocols for this approach.
- Work with the National Children’s Study Federal Advisory Committee to understand the implications for the design of the Main Study of the pilot study results and the statistical evaluations described here.
The National Children’s Study leadership is committed to a data-driven, evidence-based, and community and participant informed model for decision making. The National Children’s Study Program Office intends to announce funding opportunities in FY 2012 for continuation of the Vanguard Study (for award in FY 2012) and for the Main Study (for award in FY 2013).
In addition, when Committees consider annual appropriations for each agency, they issue reports that accompany each of the 12 appropriations bills. These reports spell out in more detail how the Committees would like the federal agencies to spend the funds they are provided. Agencies must respond in writing to each of the “directives” in these reports, which are known as “significant items.”
Senate Appropriations Committee Report FY 2013
The Senate Appropriations Committee recommendation is sufficient to allow up to $189.215 million to be used for continuation of the National Children’s Study.