Abstract
INTRODUCTION: Currently, there are no validated food frequency questionnaires (FFQs) for evaluating nutrient intake in Ukrainian adults. This study aimed to adapt and validate the European Prospective Investigation into Cancer Food Frequency Questionnaire (EPIC-Norfolk FFQ) for this population group. METHODS: Adults aged 18-54 years (n=90) living in different regions of Ukraine completed the new Ukrainian version of the EPIC-Norfolk FFQ and provided information about their 24-hour dietary recall. Raw and energy-adjusted data were analysed using Spearman's correlation coefficients, Wilcoxon signed-ranks test, cross-classification method, weighted kappa and Bland-Altman analysis. RESULTS: Correlations ranged from 0.0738 (retinol equivalents) to 0.458 (total energy and phosphorus) and were statistically significant for all nutrients except cholesterol and vitamin A (as retinol and retinol equivalents). The percentage of participants classified into the same and adjacent quartiles ranged from 61.11% (vitamin A as retinol equivalents) to 81.11% (vitamin D). Gross misclassification into the opposite quartile ranged from 3.33% (magnesium) to 10% (cholesterol, vitamin A as retinol and retinol equivalents). Using the weighted kappa, most nutrients had a fair agreement (ĸ=0.21-0.40). Energy adjustment did not affect the results for most nutrients. Bland-Altman plots confirmed overestimation of the absolute intake of most nutrients and appeared to underestimate total sugars intake by FFQ; nevertheless, there was good agreement between the two methods. CONCLUSION: The new Ukrainian version of the FFQ demonstrated reasonable relative validity for ranking an individual's nutrient intake. The overestimation of the absolute intake of most nutrients is comparable to or even less than that in other FFQ validation studies. We cannot recommend the current Ukrainian version of the FFQ for the assessment of vitamin A (as retinol and retinol equivalents) consumption because of significant differences in results between the two methods.