Reproducibility and validity of an FFQ developed for the Korea National Health and Nutrition Examination Survey (KNHANES)

Abstract

Objective: We aimed to evaluate the reproducibility and validity of the newly developed FFQ for the Korean National Health and Nutrition Examination Survey (KNHANES) and to estimate the measure's calibration factors. Design: The 109-item FFQ was administered twice, approximately 9 months apart. We also collected four seasonal 3 d dietary records (DR) as a reference method. Correlation coefficients and joint classification were computed to compare intakes of energy, thirteen nutrients and eleven food groups between the two FFQ to evaluate reproducibility. For validity, de-attenuated and energy-adjusted correlation, joint classification and Bland-Altman statistics were calculated for energy and nutrients between the first FFQ and the DR. To calibrate the FFQ, we performed a linear regression analysis in which the DR were the dependent variables and FFQ, age and sex were the independent variables. Setting: Seoul metropolitan area, Republic of Korea. Subjects: A total of 126 adults aged 20-65 years. Results: The average correlation coefficients measuring reproducibility were 0·54 for nutrients and 0·57 for food groups. The mean correlation coefficient measuring validity was 0·40 for all nutrients between the first FFQ and the DR. On average, 75 % of the participants were classified into the same or adjacent quartiles, while 5 % of the participants were grossly misclassified. The mean energy and nutrient intakes estimated by the calibrated FFQ were similar to the means estimated by the DR. Conclusions: The newly developed FFQ for assessing dietary intake in the KNHANES has acceptable reproducibility and modest validity compared with a 12 d DR collected over a 9-month period.

Estimating change in cardiovascular disease and diabetes burdens due to dietary and metabolic factors in Korea 1998–2011: a comparative risk assessment analysis

“…Therefore, there is a possibility that intake amounts have been overestimated or underestimated. Nevertheless, the FFQ in KNHANES has substantial reproducibility and validity,53 and has been used to measure the long-term dietary pattern in a specific target population 54. Second, we could not distinguish fruit from fresh fruit and fruit juice or vegetables from pickled vegetables and fresh vegetables, as KNHANES did not investigate those items separately.…”

Selected Food Consumption Mediates the Association between Education Level and Metabolic Syndrome in Korean Adults

“…Dietary data were collected from the KNHANES using food frequency questionnaire (FFQ) which was validated [22,23]. Consumption of specific food groups was determined using a FFQ from the KNHANES 2008-2011.…”

Association between socioeconomic status and oral health behaviors: The 2008–2010 Korea national health and nutrition examination survey

“…Daily food intake was assessed using the 24-h recall method, and a food frequency questionnaire was used to determine food consumed the previous day. Energy and fat intake were calculated using a food database developed for the KNHANES and the food composition table published by the National Rural Living Science Institute under the Rural Development Administration (18).…”