Adherence
A semi-quantitative food frequency questionnaire (FFQ) with 190 items provides a reproducible and reasonably valid measure of long-term dietary intake for epidemiological studies in Greek populations.
For large-scale health studies, a well-designed food frequency questionnaire is a valid and reliable tool for assessing long-term dietary habits, especially when validated against biochemical markers. It is more practical and less burdensome than daily diet records for large cohorts.
These data indicate that the semi-quantitative FFQ is reproducible and provides a reasonably reliable measure of intake. Significant correlations between diet and an independent biochemical marker further corroborate the relative validity of our questionnaire in this Greek population.
Why this rating
The study uses a robust validation design with 98 participants, repeated measures, 24-hour recalls, and biochemical markers (plasma/urine), though the sample size is small.
Source
Reproducibility and relative validity of an extensive semi-quantitative food frequency questionnaire using dietary records and biochemical markers among Greek schoolteachers
Klea Katsouyanni · International Journal of Epidemiology · 1997
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