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

Abstract

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(b-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 À0.08 (lycopene) to 0.44 (a-carotene). For the residuals the correlation coefficients ranged from À0.004 (lycopene) to 0.47 (a-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.

Validity and Reliability of a Dish-based, Semi-quantitative Food Frequency Questionnaire for Korean Diet and Cancer Research

“…Many studies have reported an increase in correlation coefficients after adjusting for energy (Ahn et al, 2007;Brunner et al, 2001;Shim et al, 2002;Watson et al, 2009;Willett, 1998), but we found no increase in correlation coefficients after energy adjustment. Our finding was supported by other studies, which reported either a decrease or no improvement in correlation coefficients (Du et al, 2009;Fumagalli et al, 2008;Quandt et al, 2007;Toft et al, 2008). Quandt et al (2007) postulated that this result comes from respondents' underreporting of some macronutrients.…”

“…However, the correlation coefficient for carrots was low; this may be because carrots are not usually consumed in isolation from other foods. The Spearman's correlation coefficient for calcium was similar or higher compared to other studies (Fregapane & Asensio-Garcia, 2000;HackerThompson et al, 2009;Jaceldo-Siegl et al, 2010;Lyu et al, 2007;Toft et al, 2008;Watson et al, 2009;Zemel et al, 2010). The correlation coefficient for sodium was low, but this result was also found in many other studies (Carithers et al, 2009;Fumagalli et al, 2008;Jaceldo-Siegl et al, 2010).…”

Differential relationship between physical activity and progression to diabetes by glucose tolerance status: the Inter99 Study

“…A family history of diabetes was defined as having a first-degree relative with diabetes. Dietary intake was assessed by a validated food-frequency questionnaire of dietary intake during the previous month [28,29].…”

Improved Glucose Tolerance after High-Load Strength Training in Patients Undergoing Dialysis

“…Physical activity outside the training was assessed using a question in The Danish Health and Morbidity Survey 2005 Questionnaire [8]. Food intake was assessed using a modified 7-day version of the Inter99 food frequency questionnaire [9] and the energy intake was determined with the aid of Master Diætist data software (Anova Data A/S, Holte, Denmark).…”