• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.2
• /
• pp.545-552
• /
• 2012

This study evaluated the validity and reliability of applying a newly developed dish-based, semi-quantitative food frequency questionnaire (FFQ) for Korean diet and cancer research. The subjects in the present study were 288 Korean adults over 30 years of age who had completed two FFQs and four 3-day diet records (DRs) from May 2008 to February 2009. Student's t-tests, Chi-square tests, and Spearman's rank correlation coefficients were used to estimate and compare intakes from different dietary assessment tools. Agreement in quintiles was calculated to validate agreement between the results of the second FFQ (FFQ-2) conducted in February 2009 and the DRs. Median Spearman's correlation coefficients between the intake of nutrients and foods assessed by the FFQ-1 and FFQ-2 were 0.59 and 0.57, respectively, and the coefficients between the intake of nutrients and foods assessed by the FFQ-2 and the DRs were 0.31 and 0.29, respectively. The quintile classifications of same or adjacent quintile for intake of nutrients and foods were 64% and 65%, respectively. Misclassification into opposite quintiles occurred in less than 5% for all dietary factors. Thus this newly-developed, Korean dish-based FFQ demonstrated moderate correspondence with the four 3-day DRs. Its reliability and validity are comparable to those reported in other studies.

• Nutrition Research and Practice
• /
• v.5 no.3
• /
• pp.260-265
• /
• 2011

The objectives of this study were to develop a food-frequency questionnaire (FFQ) for Vietnamese female immigrants in Korea and to evaluate the validity of the FFQ. A total of 80 food items were selected in developing the FFQ according to consumption frequency, the contribution of energy and other nutrients, and the cooking methods based on one-day 24 hour recall (24HR) from 918 Vietnamese female immigrants between November 2006 and November 2007. The FFQ was validated by comparison with 24HR of 425 Vietnamese female immigrants between November 2008 and August 2009. The absolute nutrient intake calculated from the FFQ was higher than that estimated by 24HR for most nutrients. The correlation coefficients between 24HR and FFQ ranged from 0.10 (vitamin C) - 0.36 (energy) for crude intake, 0.05 (vitamin E) - 0.32 (calcium) for per 1000 kcal, and 0.08 (zinc) - 0.34 (calcium) for energy-adjusted, respectively. More than 70% of subjects were classified into the same or adjacent agreement groups for nutrients other than fiber, sodium, vitamin A, vitamin C, and vitamin E, while less than 10% of subjects were classified into complete disagreement groups. We conclude that the FFQ appears to be an acceptable tool for estimating nutrient intake and dietary patterns of Vietnamese female immigrants in Korea. Future studies to validate the FFQ using various biomarkers or other dietary assessment methods are needed.

• Nutrition Research and Practice
• /
• v.10 no.4
• /
• pp.433-441
• /
• 2016

BACKGROUND/OBJECTIVES: The purpose of this study was to develop a dish-based semiquantitative food frequency questionnaire (FFQ) for Korean adolescents and evaluate its reproducibility and validity. SUBJECTS/METHODS: Based on 24-hour dietary recall data from the 4th Korean National Health and Nutrition Examination Survey (KNHANES), we developed a FFQ with 71 items. From a quota sample of 160 adolescents recruited using gender and age group as stratification variables, 153 participated in the complete data collection process. The FFQ was administered to each subject twice, at an interval of 3-4 weeks, to evaluate the test-retest reliability. The validity of the FFQ was assessed relative to 8-day food record data. RESULTS: The study findings demonstrated the FFQ's satisfactory reproducibility. Spearman correlation coefficients ranged from 0.64(for ${\beta}-carotene$) to 0.81(for protein). From cross-classification analyses, the proportion of subjects in the same intake quartile was highest for protein (65.4%) and lowest for vitamin A(47.1%). With regard to validity analysis, Spearman correlation coefficients ranged from 0.27(for vitamin A and fiber) to 0.90 (for energy). The proportions of subjects in the opposite categories between the first FFQ and the 8-day food record data were generally low within the range from 0.74% (for energy and carbohydrate) to 13.2% (for ${\beta}-carotene$). CONCLUSIONS: In conclusion, the dish-based semiquantitative FFQ developed in this study can be useful for grouping Korean adolescents according to major macro- and micronutrient intakes with reasonable reproducibility and validity.

• Journal of Nutrition and Health
• /
• v.34 no.6
• /
• pp.688-700
• /
• 2001

Nutrient intakes estimated using a 24-hr recall, a dirt record and a food frequency questionnaire(FFQ) were compared in a group of ninety-four elderly people(21 males, 73 females) in Cheongju, a city in Chung-Buk province. Mean intakes for energy, protein, Ca, p, Na, K thiamin and niacin obtained from the diet record were higher than those from the 24-hr recall. Mean intakes for energy, protein, Ca, P, Na, K thiamin, niacin and vitamin C from the FFQ were higher than those obtained from the 24-hr recall or the diet record. Correlation coefficients between the nutrient intake values from the 24-hr recall and those from the diet record ranged from 0.84 to 0.95 and were significantly correlated(p < 0.001). About 80% of the subjects in the lowest quintile by the 24-hr recall were also in the lowest two quintiles by the diet record. While the percentage fallen into the opposite category ranged from 0% to 15%. For most nutrients, at least 65% of the subjects when classified by the 24-hr recall fell into the same quintile when classified by the diet record, and the mean kappa value was 0.7. About 52% of the subjects in the lowest category by the 24-hr recall fell into the lowest two categories by FFQ. The mean percentage of the subjects in the lowest quintile by the diet record or in the lowest two quintiles by the FFQ was 51%. For most nutrients, at least 24% of each of the subjects when classified by both the 24-hr recall and the diet record fell into the same category when classified by the FFQ. The kappa values between the 24-hr recall or the diet recall and the FFQ were 0.17. These data indicate that in elderly subjects the 24-hr recall can provide very similar information to that obtained from the diet record but the FFQ can not provide good information if the right FFQ method is not used for only elderly subjects.

• Korean Journal of Community Nutrition
• /
• v.17 no.2
• /
• pp.156-166
• /
• 2012

The aim of this study was to develop and evaluate the simple semi-quantitative food frequency questionnaire (FFQ) for assessing folate intake in women of reproductive age. We developed a 30-item FFQ, and tested the reliability and validity in 97 women aged between 20 and 39 yrs using the FFQs and 24-h recalls, which were carried out twice, respectively. Assessing the reliability, the correlation coefficients were 0.53 (Spearman's) and 0.49 (Pearson's) for folate. There was no significant difference of folate intake between FFQ1 and FFQ2. 36.1% subjects were classified into the same quartile and 83.5% into the same or adjacent quartile divided by folate intake. On determining the validity, the mean folate intake obtained from the FFQ (FFQ1) and 24h-recalls (2-d) were $306.6{\pm}167.2{\mu}g/d$ and $326.9{\pm}103.3{\mu}g/d$, respectively. There was no significant difference between folate intakes from the two methods. The correlation coefficients for folate were 0.24 (Spearman's) and 0.26 (Pearson's). 39.2% of the subjects were categorized into the same quartile and 70.1% were into the same or adjacent quartile. In addition, sensitivity (64.3%) and specificity (62.3%) were estimated to evaluate the adequacy of folate intake. These results suggest that this FFQ would be a useful and a valuable instrument to assess the intake of folate among the Korean women of child-bearing age.

• Nutrition Research and Practice
• /
• v.16 no.6
• /
• pp.789-800
• /
• 2022

BACKGROUND/OBJECTIVES: The aim of this study was to examine the validity and reproducibility of a food frequency questionnaire (FFQ) developed in Korea for breast cancer survivors. SUBJECTS/METHODS: Ninety-nine breast cancer survivors who completed an FFQ twice and three 3-day dietary records (DRs) between 2016-2017 were included. Energy and 14 nutrient intakes were calculated from FFQs and DRs. To determine the validity of the FFQ, energy-adjusted de-attenuated Pearson correlations between two FFQ assessments and the average of the three 3-day DRs were calculated, and to determine reproducibility, energy-adjusted Pearson correlations and degrees of agreement were calculated between the first and second FFQ assessments. RESULTS: Correlation coefficients of validity ranged from 0.29 (protein) to 0.47 (fat) (median value = 0.36) for the FFQ assessment and from 0.20 (riboflavin) to 0.53 (calcium) (median value = 0.37) for the second. Correlation coefficients of reproducibility ranged from 0.22 (sodium) to 0.62 (carbohydrate) (median value = 0.36). Regarding FFQ reproducibilities, percentage classifications of exact agreements for energy-adjusted nutrients ranged from 27.3% (sodium) and 45.5% (fat). A median 76.8% of participants were classified into the same or adjacent quartiles, while a median of 5.6% of participants were classified in extreme quartiles. Bland-Atman plots for the majority of data points of three macronutrients, calcium and vitamins A and C fell within limits of agreement. CONCLUSIONS: These results indicated that the newly developed FFQ for Korean breast cancer survivors has acceptable validity and reproducibility as compared with three 3-day DRs collected over a one-year period.

• Journal of Nutrition and Health
• /
• v.28 no.9
• /
• pp.914-922
• /
• 1995

A food frequency questionnaire (FFQ), which can be used in studies investigating relationship between diet and chronic diseases in a rural area of Korea, was developed and validated. Food items were selected from two sources ; (1) preliminary survey in a rural area by 24-hour recalls and (2) National Nutritional Survey of 1991. Sixty-five food items were finally selected based on the frequency of consumption and contributions to major nutrient intakes. Portion size of each food item was determined considering the mean and median values of the amounts consumed by subjects in the preliminary survey. Frequency of consumption was asked in nine categories ranging from 'more than three times a day' to 'almost never'. The newly developed FFQ was administered in 24-hour recalls conducted in different seasons in the same area after the administration of FFQ. Sixty-one subjects completed both FFQ and all three repeated 24-hour recalls. The results of the two different survey methods showed that mean daily intake levels of energy, carbohydrate, vitamin A and vitamin C were significantly higher in FFQ compared to 24-hour recalls(p<0.05). Intake levels of energy, protein, fat, carbohydrate and iron were significantly correlated by Pearson's correlation coefficients(p0.05). Ranking on nutrient intake of the subjects by two method were significantly correlated(Spearman's correlation coefficients) in all above nutrients plus Ca and vitamin A. Percentage of subjects in the lowest or in the highest quintile by 24-hour recalls who belong to the nearest two categories by FFQ ranged from 46% to 83%, while the percentage falling into the opposite category were below 10% in most of the nutrients. The proportion of subjects classfied into the same quintiles by the two methods were between 23% and 33%, with an average of 28%. From the results, FFQ developed in this study seems to be useful in evaluating nutrient intake pattern of 1 year in adults living in rural area of Kyonggi province.

• Journal of Nutrition and Health
• /
• v.33 no.3
• /
• pp.314-324
• /
• 2000

Evaluation of nutritional status of the elderly imposes different problem from the other age groups. It is essential to use right instrument to assess food consumption. In Korea, the food frequency questionnaire has not been applied widely to elderly people. The purpose of this study is to assess the possibility of employing a semi-quantitative food frequency questionnaire(FFQ) for the Korean elderly to estimate nutrient and/or food intakes. In this study the FFQ for the elderly was developed and validated. The subjects were 144 free-living old women aged from 65 to 90. The FFQ was designed with 4 items for cereals and 86 items for other foods and with frequency of 12 intervals. Three portion sizes were given to select : 1/2 of standard amount, standard amount, and 11/2 of standard amount. ach subject was interviewed with newly developed FFQ form and same subjects were also involved to complete 3-day diet record. Nutrient intake was calculated using software program developed by our group. The nutrient intakes by the FFQ was validated by comparing the results with 3-day diet record. The FFQ estimated significantly higher mean intakes of energy, carbohydrate, protein, fats and vitamin C than did the diet reconrds(p<0.05). Pearson's correlation coefficients between two methods ranged from 0.21 for vitamin Q to 0.69 for alcohol(mean r=0.53). From 32% to 42% of the subjects were classified in the same quintile of nutrient intake by two methods, and 63% to 84% were classified in the same or adjacent quintile. On average, only 4% of the subjects were misclassified into extreme quitiles. The results indicate that the FFQ developed for the elderly in this study is useful for classifying individuals by rank and identifying groups at extremes of nutrient intakes.

• Korean Journal of Community Nutrition
• /
• v.7 no.2
• /
• pp.277-285
• /
• 2002

The purpose of this study was to develop a semi-quantitative food frequency questionnaire (SQ-FFQ) for subjects aged 50yr and over and to evaluate the validity of this SQ-FFQ. Dietary intake was assessed using SQ-FFQ that included 98 commonly consumed flood items selected from the results of the Korean Health and Nutritional Survey, 1998. Subjects (n = 2,660) aged 50yr and over were recruited from 7 metropolitan cities and 8 small cities. Each subject was interviewed using this SQ-FFQ developed in our laboratory and 24hr-recall method. Excluding incomplete data, Data from 1,149 subjects were used in this validity study. The nutrient intakes assessed by this SQ-FFQ were validated by comparing with the results from 1 day 24-hour recalls. Pearson's correlation coefficients between two methods were 0.71, 0.64, 0.53, and 0.43 for energy, carbohydrate, protein, and fat, respectively for all subjects. Spearman's correlation coefficients were higher than those of Pearson's correlation coefficients. Kappa values for energy, carbohydrate, protein, and fat were 0.79, 0.72, 0.70, and 0.64, respectively. The percentage for misclassification of the lowest quartile into the highest quartile or vice versa was 1.25-1.39% for all nutrients. Therefore, this SQ-FFQ seems to be useful in assessing the nutritional status of the middle-aged and elderly subjects in Korea.

• Korean Journal of Community Nutrition
• /
• v.21 no.5
• /
• pp.440-450
• /
• 2016

Objectives: We previously developed a dish-based semi-quantitative food frequency questionnaire (FFQ) for Korean adolescents and reported that it had reasonable reliability and validity. The objective of the current study was to construct a web-based dietary evaluation system applying the FFQ for Korean adolescents and examine its applicability in the context of reliability and validity. Methods: A web-based food frequency questionnaire system was designed using a comprehensive approach, incorporating not only dietary data survey but also up-to-date nutrition information and individualized eating behavior guidelines. A convenience sample of 50 boys and girls aged 12~18 years agreed to participate in the study and completed the FFQ twice and 3 days of dietary recall on the developed website during a two-month period. The FFQ's reliability and validity was examined using correlation and cross classification analysis. We also measured participants' subjective levels of the web site's usability, visual effect, understanding, and familiarity. Results: Spearman correlation coefficients for reliability ranged from 0.74 (for vitamin A) to 0.94 (for energy). From cross-classification analyses, the proportion of subjects in the same intake quartile was highest for energy (82.0%) and lowest for vitamin A (56.0%). With regard to validity analysis, Spearman correlation coefficients ranged from 0.34 (for fiber) to 0.79 (for energy). The proportions of subjects in the opposite categories between the first FFQ and 3-day diet recall data were generally low from 0.00% (for fat) to 36.2% (for sodium). Average subjective levels of the website's usability, visual effect, understanding, and familiarity were all found to be over 4 points out of 5 points. Conclusions: The web-based dietary evaluation system developed can serve as a valid and attractive tool for administering FFQ to Korean adolescents.