a1 School of Population Health, University of Western Australia, Crawley, Western Australia 6009, Australia
a2 Menzies School of Health Research, Casuarina, Northern Territory 0811, Australia
a3 Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia 6009, Australia
Objectives: To compare a widely used Australian food-frequency questionnaire (FFQ) with diet records and consider the results in relation to its use in nutrition surveillance.
Design: Inter-method reliability study.
Setting: A randomised trial in subjects with past asbestos exposure.
Subjects: Seventy-two adults living in Western Australia.
Methods: A semi-quantitative FFQ developed by the Commonwealth Scientific Industrial Research Organisation in South Australia was administered after the completion of four 7-day diet records (DRs).
Results: Mean agreement between methods was not significantly different from 100% for many nutrients, but the limits of agreement indicated that, at the individual level, the FFQ over- or underestimated the DR by at least 50%. Mean agreement between methods decreased significantly with increasing intakes for the majority of nutrients. Pearson's correlation coefficients were less informative indicators of agreement compared with the limits of agreement.
Conclusions: These results indicate poor agreement between the FFQ and DR when estimating absolute intakes. Therefore, comparing intakes collected using this FFQ with specific cut-off points such as Recommended Dietary Intakes for nutrition surveillance may lead to seriously flawed conclusions about population intakes.
(Received April 09 2002)
(Accepted October 21 2002)