A COMPUTERIZED DIET HISTORY QUESTIONNAIRE FOR EPIDEMIOLOGIC STUDIES

Objective To describe methods used to computerize the diet history que stionnaire developed for the Coronary Artery Risk Factor Development i n Young Adult (CARDIA) study and to describe quality-control procedure s used in conjunction with dietary assessment. Design The computerized diet history is being used in a case-control study. Because of the co mputerized nature of the questionnaire, we developed quality-control p rocedures that incorporate listening to an audiotape of the interview while visually reviewing recorded data. Setting Three centers involved in a population-based epidemiologic study of colon cancer. Subjects M en and women between the ages of 30 and 79 years. Results Quality-cont rol results showed that 100% of the computerized forms would be free o f errors if the data were subjected to visual review only. Probing err ors, which accounted for 47.3% of all errors, were the most commonly e ncountered errors. In probing errors the interviewer did not probe in a nondirective manner, or the interviewer failed to verify responses t hat might be considered questionable. Applications The CARDIA diet his tory was computerized for use in epidemiologic studies of the associat ion between diet and disease. Review of the audiotapes of the intervie ws showed that most errors made in obtaining a dietary assessment were not detectable from visual review of the data. Although the quality-c ontrol procedures were developed for a computerized diet history quest ionnaire, they are applicable to other dietary assessment methods.