Objective: To examine the utility of a shorter FFQ compared with a longer FFQ, both of which are commonly used in Australia. Design: Comparative study. Setting: Community setting. Subjects: One hundred and fifty-nine men (mean 55 (SEM 7) years) screened for participation in an intervention study completed both the Commonwealth Scientific and Industrial Research Organisation FFQ and the Cancer Council of Victoria FFQ. Agreement between both questionnaires was assessed according to Bland-Altman plots and limits of agreement (LOA) and ordinary least products regression to test for the presence of fixed and proportional bias. Results: There was good relative agreement between the methods for energy and macronutrients (Pearson's correlation coefficients: energy r 5 0?7, protein r 5 0?6, fat r 5 0?8, carbohydrate r 5 0?7, alcohol r 5 0?8; P , 0?01). Mean group-level agreement for the majority of nutrients (70 %) fell between 80 % and 110 %. According to the criteria used (maximum LOA was 50-200 % and no significant proportional bias), there was acceptable agreement between the FFQ for energy and total saturated and monounsaturated fat, but not for protein, carbohydrate and fibre. Micronutrients that did not meet the agreement criteria including calcium, iron, thiamin, niacin, riboflavin and folate. When the data were analysed according to quintiles, the majority of subjects were either in exactly the same quintile or within one quintile for most nutrients, and 1-2 % were grossly misclassified by three or four quintiles. Conclusions: We conclude that there is sufficient agreement between the instruments for group-level comparisons in men, but they are not interchangeable for estimation of individual intakes.
Keywords
Food frequency questionnaireDietary intake FFQ are widely used to assess dietary intake (1,2) . They are relatively low cost, are easy to administer and can assess dietary intake over a long period of time (3) . In Australia, there are two FFQ that are frequently used to assess dietary intake: the Commonwealth Scientific and Industrial Research Organisation (CSIRO) FFQ and the Cancer Council of Victoria (CCV) FFQ (4,5) . The characteristics of each instrument are different. The CCV FFQ is a seventyfour-item self-administered FFQ, which is optically scannable to provide an analysis of dietary intake. It is quick and easy to use and has been validated in relation to 7 d weighed food records in premenopausal women. However, it is thought to underestimate carbohydrate intake; it has a truncated upper range of frequency categories and does not include some common foods (6) . The CSIRO FFQ contains 200 items, has serving sizes that can be altered by the respondent and can be modified, i.e. extra questions can be added according to the particular focus of the study. However, it is a booklet that takes 45 min to complete and has to be manually coded before the manual data entry, increasing both the respondent burden and the resources required to analyse the FFQ. The CSIRO FFQ had been validated by ourselve...