Analyzing Dietary Intake Data with PC-SIDE

• Activity Number: 53
• Type: Invited
• Date/Time: Sunday, August 11, 2002 : 6:00 PM to 8:00 PM
• Sponsor: ASA
• Author(s): Kevin Dodd*+ and Todd Krueger and Alicia Carriquiry
• Affiliation(s): National Cancer Institute and Iowa State University and Iowa State University

Abstract

Researchers at Iowa State University developed statistical methods for estimating the distributions of usual food and nutrient intakes for populations and subpopulations. These distributions are required to determine the proportions of the population who are at risk for inadequate intake of essential nutrients or for excessive intake of undesirable dietary constituents, including pesticide, antibiotic, or chemical residues. The approach is based on the assumption that individuals can more accurately recall the types and amounts of foods they ate yesterday than they can recall intake over a longer period of time. When at least two days of dietary information are available for some individuals in the sample, it is possible to estimate long-term average intake by removing the within-person variation in intake in order to obtain better estimates of the distribution of usual, or long-term average intake. Methods for estimating distributions of usual food intakes have been developed for the case when the probability of consumption is independent of the amount consumed.

Many statistical procedures are based on the assumptions that the data under investigation are normally distributed