MEASUREMENT ERROR IN DIETARY DATA - IMPLICATIONS FOR THE EPIDEMIOLOGIC-STUDY OF THE DIET-DISEASE RELATIONSHIP

Objectives: To examine the effect of measurement error in dietary data on the relationship between diet and body mass index (BMI). To correc t for the effect of measurement error on diet-BMI association by using replicate measurements of diet. The effect of measurement error on di et-BMI relationship was simulated, and its implications are discussed. Design: Prospective study design. Setting: The first and second China Health and Nutrition Survey conducted in 1989 and 1991, respectively. Subjects: Three thousand, four hundred and seventy-nine adults age 20 -45 y at the 1989 survey. Methods: Statistical methods were used to de monstrate the effect of measurement error in dietary data on the diet- BMI association. Results: By using the average of three replicate 24 h dietary recalls, the attenuation of diet-BMI association was reduced substantially. The regression coefficients of fat and energy intakes d iffered markedly from those computed by using only single measurement of diet. Conclusions: Measurement error in dietary data may significan tly attenuate the diet-disease association. Where appropriate, specifi c emphasis may be needed to address the problem of measurement error i n the study of diet-disease relationship.