Comparability of food frequency questionnaires between Korean Children's Environmental Health Study (Ko-CHENS) and Korean Genome and Epidemiology Study (KoGES) in pregnant women.

BACKGROUND/

OBJECTIVES

The Korean Children's Environmental Health Study (Ko-CHENS) developed a food frequency questionnaire (FFQ) to assess maternal dietary intake during pregnancy. This FFQ shares high structural similarity with the validated FFQ of the Korean Genome and Epidemiology Study (KoGES), a representative dietary assessment tool for the Korean adult population, which includes 97 of the 112 items in the Ko-CHENS FFQ. The comparability of the Ko-CHENS and KoGES FFQs among pregnant women was evaluated.

SUBJECTS/

METHODS

Ninety-four women recruited from Kangwon National University Hospital between December 2024 and February 2025 were included. The participants consecutively completed the Ko-CHENS and KoGES FFQs. The nutrient intakes were adjusted for the total energy intake using the residual method. Log-transformed intakes of energy, nutrients, and food groups were compared using the correlation coefficients, cross-classification percent agreement, weighted kappa statistics, and Bland-Altman plots.

RESULTS

The Ko-CHENS FFQ yielded higher absolute intake estimates for energy and the majority of nutrients and food groups than the KoGES FFQ. The Pearson or Spearman correlation coefficients ranged from 0.34 (vitamin E) to 0.68 (β-carotene) for energy and nutrients and from 0.15 (sugars and jams) to 0.77 (salted vegetables) for food groups, with median values of 0.55 and 0.61, respectively. The median proportions of the participants classified into the same or adjacent quartiles were 96.39% for energy and nutrients and 96.52% for food groups. The weighted kappa statistics ranged from 0.23 to 0.52 for energy and nutrients and from 0.06 to 0.59 for food groups, with median values of 0.38 and 0.45, respectively. The Bland-Altman plots for energy and macronutrients showed that the data points were primarily within the limits of agreement.

CONCLUSION

The Ko-CHENS and KoGES FFQs showed fair-to-moderate comparability, suggesting that the Ko-CHENS FFQ can be used for ranking Korean pregnant women based on their dietary intake levels.