Computer-assisted self-interviewing: a multimedia approach to dietary assessment.

Currently available dietary assessment tools have limited ability to obtain valid data within the resource constraints of large-scale studies. Many obstacles to gathering data can be overcome with computer-assisted self-interviewing (CASI). Computers can conduct personalized, in-depth interviews without interviewers; provide standardized data collection with appropriate levels of probing; automate data entry; encourage subjects to review and correct inconsistent data; and ensure that responses are complete. Interactive multimedia tools can motivate subjects and improve participation. Visual and aural cues may stimulate recall and improve data quality. CASI is appropriate for use in populations in which literacy is low and in multiple ethnic groups. A prototype CASI diet-history program was developed for use in the United States. The diet-history approach was selected to improve cognitive support and capture information on usual diet. Scripts were based on recorded interviews with dietitians and interviewers from the National Health and Nutrition Examination Survey. At the end of the interview, participants are given information on how their reported nutrient intakes compare with current recommendations for their age and sex. The prototype was tested in focus groups of mixed age, sex, ethnicity, and education, with encouraging results. The development of multimedia-based dietary assessment tools seems a logical next step in improving dietary assessment methods.