TY - JOUR

T1 - Relative validity of a food frequency questionnaire used in the Inter99 study

AU - Toft, Ulla Marie Nørgaard

AU - Kristoffersen, Lis

AU - Ladelund, S

AU - Bysted, A

AU - Jakobsen, J

AU - Lau, Cathrine

AU - Jørgensen, Torben

AU - Borch-Johnsen, Knut

AU - Ovesen, L

N1 - Keywords: 4-Aminobenzoic Acid; Adult; Biological Markers; Carotenoids; Denmark; Diet; Diet Records; Diet Surveys; Female; Fruit; Humans; Male; Middle Aged; Nitrogen; Nutrition Assessment; Questionnaires; Reproducibility of Results; Sensitivity and Specificity; Statistics, Nonparametric; Vegetables

PY - 2007

Y1 - 2007

N2 - OBJECTIVE: To evaluate the validity of the Inter99 food frequency questionnaire (FFQ) compared with a 28-days' diet history and biomarkers. SUBJECTS: A random sample of 13 016 individuals were drawn from a general population and invited for a health screening programme. Participation rate was 52.5%. All high-risk individuals were re-invited for assessment after 1 and 3 years and completed a 198-item FFQ at all three occasions. Participants attending for 3 years follow-up were invited to participate in the validation study, including a 28-days' diet history, a 24-h urine collection and a fasting blood sample. Overall, 264 subjects participated. RESULTS: Spearman's rank correlation coefficients between the two dietary methods ranged from 0.31(beta-carotene) to 0.64 (fruits) in men and from 0.31 (polyunsaturated fat and sodium) to 0.64 (fruits) for women. The proportion of individuals classified in the same or adjacent quintiles were, on average, 72% for men and 69% for women. Gross misclassification was found on average in 2%. The correlation coefficients of the residuals ranged from 0.27 (sodium) to 0.61 (fruits) for men and from 0.21 (sodium) to 0.62 (B12-vitamin) for women. Correlation coefficients between fruit and vegetable intake and carotenoids ranged from -0.08 (lycopene) to 0.44 (alpha-carotene). For the residuals the correlation coefficients ranged from -0.004 (lycopene) to 0.47 (alpha-carotene). CONCLUSION: The Inter99 FFQ and the residuals of the intake provide acceptable classification of individuals according to their dietary intakes and the FFQ gives a good quantitative measurement of key dietary components.

AB - OBJECTIVE: To evaluate the validity of the Inter99 food frequency questionnaire (FFQ) compared with a 28-days' diet history and biomarkers. SUBJECTS: A random sample of 13 016 individuals were drawn from a general population and invited for a health screening programme. Participation rate was 52.5%. All high-risk individuals were re-invited for assessment after 1 and 3 years and completed a 198-item FFQ at all three occasions. Participants attending for 3 years follow-up were invited to participate in the validation study, including a 28-days' diet history, a 24-h urine collection and a fasting blood sample. Overall, 264 subjects participated. RESULTS: Spearman's rank correlation coefficients between the two dietary methods ranged from 0.31(beta-carotene) to 0.64 (fruits) in men and from 0.31 (polyunsaturated fat and sodium) to 0.64 (fruits) for women. The proportion of individuals classified in the same or adjacent quintiles were, on average, 72% for men and 69% for women. Gross misclassification was found on average in 2%. The correlation coefficients of the residuals ranged from 0.27 (sodium) to 0.61 (fruits) for men and from 0.21 (sodium) to 0.62 (B12-vitamin) for women. Correlation coefficients between fruit and vegetable intake and carotenoids ranged from -0.08 (lycopene) to 0.44 (alpha-carotene). For the residuals the correlation coefficients ranged from -0.004 (lycopene) to 0.47 (alpha-carotene). CONCLUSION: The Inter99 FFQ and the residuals of the intake provide acceptable classification of individuals according to their dietary intakes and the FFQ gives a good quantitative measurement of key dietary components.

U2 - 10.1038/sj.ejcn.1602815

DO - 10.1038/sj.ejcn.1602815

M3 - Journal article

C2 - 17538538

VL - 62

SP - 1038

EP - 1046

JO - European Journal of Clinical Nutrition

JF - European Journal of Clinical Nutrition

SN - 0954-3007

IS - 8

ER -