COMPARISON OF A QUANTITATIVE DAIRY QUESTIONNAIRE WITH A DIETARY HISTORY IN YOUNG-ADULTS

Background. There is growing interest in the potential role of calcium in the prevention of osteoporosis. Therefore a quantitative dairy que stionnaire (DQ) was developed to estimate the calcium intake from dair y products. The aim of this study was to evaluate the relative validit y and reproducibility of the DQ in 27-29 year old males and females. M ethods. The DQ was validated against a cross-check dietary history met hod (DH) in 160 subjects, and the reproducibility was assessed in 29 s ubjects by repeating the administration of the DQ with a one-year inte rval. Results. In the validity study, the nutrient calcium and the foo d groups cheese and milk and milk products measured by the DQ tend to show higher intakes as compared to the results of the DH. However, onl y for the calcium intake was the difference between the DQ and DH (7%) significant. The Bland-Altman plot showed that this bias was constant over the range of calcium intakes. The Pearson correlation coefficien ts between the DQ and the DH varied from 0.58 to 0.65. On average, abo ut 52% of the subjects were classified in the same quartile in the DQ and the DH for the intake of calcium as well as dairy products. The we ighted kappas were between 0.60 and 0.67. In the reproducibility study , the Pearson correlation coefficient for the calcium intake assessed by the DQ one year apart was 0.78. Conclusions. These data indicate th at the DQ is reasonably accurate in young adults as a means of assessi ng the calcium intake from dairy products.