Challenges in converting an interviewer-administered food probe database to self-administration in the National Cancer Institute automated self-administered 24-hour recall (ASA24)

Abstract

The National Cancer Institute (NCI) is developing an automated, self-administered 24-hour dietary recall (ASA24) application to collect and code dietary intake data. The goal of the ASA24 development is to create a web-based dietary interview based on the US Department of Agriculture (USDA) Automated Multiple Pass Method (AMPM) instrument currently used in the National Health and Nutrition Examination Survey (NHANES). The ASA24 food list, detail probes, and portion probes were drawn from the AMPM instrument; portion-size pictures from Baylor College of Medicine's Food Intake Recording Software System (FIRSSt) were added; and the food code/portion code assignments were linked to the USDA Food and Nutrient Database for Dietary Studies (FNDDS). The requirements that the interview be self-administered and fully auto-coded presented several challenges as the AMPM probes and responses were linked with the FNDDS food codes and portion pictures. This linking was accomplished through a “food pathway,” or the sequence of steps that leads from a respondent's initial food selection, through the AMPM probes and portion pictures, to the point at which a food code and gram weight portion size are assigned. The ASA24 interview database that accomplishes this contains more than 1100 food probes and more than 2 million food pathways and will include about 10,000 pictures of individual foods depicting up to 8 portion sizes per food. The ASA24 will make the administration of multiple days of recalls in large-scale studies economical and feasible.

Introduction

Although interviewer-administered 24-hour recalls (24HRs) are an important tool for assessing dietary intake in population studies, the expense involved in collecting and coding each recall has prohibited the use of this methodology for many large-scale dietary studies. A 24HR interview can take approximately 30–45 min to conduct and additional time to code (Thompson and Subar, 2008). Dietary interviewers must be highly trained and experienced to collect quality interviews that provide enough information for accurate coding. Similarly, dietary coders require extensive training in order to accurately code dietary recalls to provide nutrient consumption. As a single 24HR is not considered representative of an individual's usual diet, multiple 24HRs are desired for many studies of nutrient intake. These factors contribute to the desire to simplify the process of collecting 24HRs.

USDA is the leader in 24HR methodology, having used the 24HR interviews as the primary dietary assessment method in nationwide surveys of food consumption since 1965 (Raper et al., 2004). USDA developed the multiple pass method of conducting the 24HR interview, which relies on having the interviewer question the respondent about food intake using several “passes” or reviews of the day's intake. This method has been shown to improve the ability of respondents’ recall of foods consumed (Conway et al., 2003). In 2001, USDA developed an automated 24HR tool called the Automated Multiple Pass Method (AMPM) where the computer presents questions for each food according to specifications established by USDA, thus providing standardization across interviewers (Raper et al., 2004). In addition, USDA also automated a process to assign FNDDS food codes to many of the pathways in the interview, which improved the consistency of the food coding process and decreased the coding time. Dietary coders still review each assigned food code, make corrections if needed, and assign food codes to any unmatched responses. The AMPM has been used since 2001 to collect What We Eat in America data in the National Health and Nutrition Examination Survey (WWEIA NHANES).

Although self-administered dietary interviews have been developed for the computer and the Internet (Kohlmeier et al., 2007), to date none have utilized the USDA AMPM as the source of the interview questions. In 2005, the National Cancer Institute (NCI) initiated a collaboration to develop an automated self-administered 24-hour recall (ASA24) that would employ computer technology to collect 24HRs through the Internet. The result of this collaboration is a computer-assisted 24HR that is fully auto-coded and linked to a comprehensive nutrient database. As in the AMPM interview, the ASA24 interview begins by asking the respondent to pick from a list of foods (called Food List Terms) the foods and beverages they consumed. After their list is complete, the ASA24 presents questions, referred to as probes, which the respondent must answer about each food. The resulting information (known as a “food pathway”) provides enough information to assign a food code, portion size, and nutrient data, all of which are taken from USDA's Food and Nutrient Database for Dietary Studies (FNDDS). Respondents can use Baylor College of Medicine's photographs of varying quantities of the food as aids in answering the ASA24's portion-size questions. The ASA24 interview database contains all the foods, probes and responses, and portion photographs needed for the interview.

This paper describes the collaboration and process used to develop the ASA24 interview database and discusses the challenges encountered in converting an interviewer-administered instrument to a self-administered instrument and the methods by which those challenges were resolved.