Abstract  This two-disk CD-ROM contains microdata on food and nutrient intakes from The Supplemental Children's Survey (CSFII 1998) to the 1994-96 Continuing Survey of Food Intakes by Individuals (CSFII 1994-96). CSFII 1998 was conducted in response to the Food Quality Protection Act of 1996, which required the U. S. Department of Agriculture to provide data from a larger sample of children for use by the Environmental Protection Agency in estimating exposure to pesticide residues in the diets of children. The CSFII 1998 adds intake data from 5,559 children birth through age 9 years to the intake data collected from 4,253 children of the same ages participating in the CSFII 1994-96. The CSFII 1994-96 included the collection of data from persons of all ages (1-day dietary intake data for 16,103 individuals). The 1998 survey was designed so that the data could be combined with those from the 1994-96 survey, thus the approaches to sample selection, data collection, data file preparation, and weighting in CSFII 1998 were consistent with those used in the CSFII 1994-96. The survey data files on these disks contain data from both the CSFII 1994-96 and CSFII 1998; all 4 years of data are nationally representative surveys conducted by the Agricultural Research Service of the U.S. Department of Agriculture. The data set may be analyzed in a variety of ways: the combined 1994-96, 1998 data; the 1998 data separately; the 3-year CSFII 1994-96 data; or any of the 3 years of the CSFII 1994-96 separately. The seven data files include: household, household member, sample person, food line item, daily intake (food group amounts), daily intake (nutrients), and Diet and Health Knowledge Survey (from the 1994-96 survey only).

Abstract  Below is a summary of the recommendations reached by the Methodological Subcommittee of the HNIS/NCHS Analytic Working Group on the issues of variance estimation and statistical reporting standards. Specific recommendations are underlined, whereas suggested practices are italicized. The implementation of these recommendations and suggestions will vary from survey to survey and, perhaps, from estimate to estimate. Nevertheless, official agency publications should contain a "statistical notes" section describing the variance estimation and statistical reporting standards used therein. The design-based approach to the estimation and analysis of survey data is assumed here. Unlike model-dependent alternatives, the design-based approach makes few assumptions about the nature of the data being summarized and/or analyzed. Two aspects of the sampling design must be taken into account when using this approach: the sample weights and the complex sample design (stratified, multi-stage sampling). Weights are used in the this approach when estimating mean, medians, and other descriptive statistics as well as analytical statistics like regression coefficients. Both weights and indicators of stratum and primary sampling unit (PSU) membership are used when estimating variances and testing for statistical significance. In general, using statistical weights that reflect the probability of selection and propensity of response for sampled individuals will affect parameter estimates, while incorporating the attributes of the complex sample design (i.e., clustering and stratification) will affect estimated standard errors and thereby test statistics and confidence intervals. The recommendations for presentation of statistical data that follow arise from the issue of sampling variability, and reflect the random way (in the rigorous statistical sense) in which the sample was selected. Although beyond the scope of this report, a consideration of nonsampling issues such as measurement error, nonresponse bias, and other methodological biases are necessary for any thorough interpretation and evaluation of the validity of survey findings.

Abstract  This report provides a set of early-life stage age groups for U.S. Environmental Protection Agency (EPA, or the Agency) scientists to consider when assessing children's exposure to environmental contaminants and the resultant potential dose. These recommended age groups are based on current understanding of differences in behavior and physiology that may impact exposures in children. A consistent set of early-life age groups, supported by an underlying scientific rationale, is expected to improve Agency exposure and risk assessments for children by increasing the consistency and comparability of risk assessments across the Agency, improving accuracy and transparency in assessments for those cases where current practice might too broadly combine behaviorally and physiologically disparate age groups, and fostering a consistent approach to future exposure surveys and monitoring efforts to generate improved exposure factors for children.

Abstract  The consumption of food by the general population is a significant route of potential exposure to hazardous substances that are present in the environment. For this reason, a thorough analysis of the dietary habits of the American public would aid in the identification of potential exposure pathways. To that end, the EPA developed per capita food intake rates for various food items and food categories using databases developed by the United States Department of Agriculture (USDA). These intake rates were incorporated into EPA's 1997 Exposure Factors Handbook. Since that time, EPA has recommended that the food intake study be updated and expanded to include a more comprehensive analysis of food intake. That analysis is presented in this document.