REPRODUCIBILITY OF NUTRIENT INTAKE IN A FOOD FREQUENCY QUESTIONNAIRE USED IN A GENERAL-POPULATION

This study evaluates the reproducibility of nutrient intake in a 45-it em food frequency questionnaire (FFQ). The FFQ was mailed in 1980 to p ersons eligible to participate in a large cohort study on diet and can cer risk, a follow-up version with 75 food items was mailed in 1988 to selected original participants. A random sample of 500 men and 500 wo men from the New York State general population was selected from indiv iduals who responded to both waves of the study. The subjects' 1988 re sponses were compared with their original 1980 responses; Pearson's co rrelations ranged from 0.25 for retinol to 0.55 for vitamin C with or without supplements and vitamin E with supplements in women. Reproduci bility of nutrient intake in this questionnaire indicates that brief F FQs may be a useful tool to study nutrient intake and chronic disease relationships, although they are subject to substantial measurement er ror and dietary change.