Calibration of a food frequency questionnaire in a Korean population

B57

Objective: The aim of this study was to assess how well a food frequency Questionnaire (FFQ) performed usual nutrient intakes in comparison with three-day dietary records (DRs) in Koreans who visited National Cancer Center, Korea.
 >Method: A total of 210 Koreans aged 25 years and above participated in the first phase from June till September, 2007, which was conducted using the three-day dietary record method. One hundred and ninety six of those who completed the first phase were then interviewed to test FFQ against dietary records as a reference. The mean absolute nutrient intakes estimated by the dietary records were statistically compared with those estimated by the FFQ using paired t-tests. We calculated log-transformed and de-attenuated Pearson's correlation coefficients and energy-adjusted, log-transformed and de-attenuated Pearson's correlation coefficients between intakes of nutrients based on the FFQ and DRs. Cross-classification was also calculated to evaluate the overall degree of agreement between the FFQs and DRs.
 >Result: The intakes of energy, carbohydrate and protein were higher in FFQ than in DRs, while fat intake was higher in DRs than in FFQ. The corrected correlations for attenuation varied from 0.13(ß-carotene) to 0.67(cholesterol) and the energy-adjusted and de-attenuated correlation coefficients ranged between 0.10(ß-carotene) and 0.67(cholesterol). The degree of good agreement by cross-classification between the DRs and the FFQ by quartile ranged from 65.8% (sodium) to 80.6% (caloric intake).
 >Conclusion: This calibration study indicates that the FFQ gives acceptable estimates of the usual dietary intakes among the study population. The results may verify that it is possible to use the FFQ with the benefit of being relatively easy and convenient in a large-scale epidemiological study of relationships between nutrient intakes of diseases in Korean population.