• Survey Research
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• v.1 no.1
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• pp.109-123
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• 2000

In order to make statistically valid inferences for survey data based on complex probability sample designs, survey researchers must incorporate the sample design in the data analysis If this in not the case the variance estimates of survey statistics derived under the usual simple random sampling assumptions from an infinite population generally underestimate the true variance, which results in high Type l error level. In this article we introduce new software packages dedicated to analyze complex survey data In particular, we summarize analysis capabilities on SUDAAN Version 7.5 and SAS Version 8.

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.786-794
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• 2006

The purpose of this study was to establish an association between the consumption of ready-to-eat cereal (RTEC), milk, and calcium within the context of the most current population dietary practice in Korea. Inadequate calcium intake among Korean children and adults is one of the important public health concern. Milk is one of the best calcium sources because or its bioavailability, and RTEC is one or the foods commonly consumed with milk. The most recent Korean National Health and Nutrition Survey, 2001 dataset was used as the source of data for this research. Subjects excluding pregnant women, were categorized according to gender and age ($1{\sim}5,\;6{\sim}11,\;12{\sim}19,\;20{\sim}49,\;50+$ years) and then by consumption of RTEC and milk. SAS and SUDAAN were used for statistical analyses. Sample weighted means, standard errors, and population percentages were calculated, and multiple regression model with adjustment for covariates were used to determine the predictability of total daily calcium intake from inclusion of RTEC and milk compared to the meal without RTEC and milk. RTEC was consumed by 2.4% or Korean people. Average calcium intake was 17 times greater when RTEC was consumed with milk than when RTEC was consumed without milk. Respondents who consumed RTEC with milk had significantly higher mean daily calcium and other nutrient intakes than respondents who consumed neither. in the multiple regression analysis, milk consumption with or without RTEC predicted total daily calcium intake after adjusting for age, income, and alcohol consumption (p<0.0001). The percentage of respondents below the estimated average requirement (EAR) level for calcium was lower for RTEC consumers than for RTEC non-consumers in all age-gender groups, especially significant differences were in children aged $1{\sim}5$, boys and girls aged $12{\sim}19$, men aged $20{\sim}49$, and women older than 50 years of age. RTEC consumption was not associated with intake in excess of the tolerable upper intake level (UL) for calcium. In conclusion, RTEC consumption was positively associated with both milk and calcium intakes in all age and gender groups in Korean population.

• Nutrition Research and Practice
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• v.6 no.4
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• pp.328-333
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• 2012

This study was performed to investigate the differences in food choice, nutrition labeling perceptions, and prevalence of obesity due to meal skipping in Korean elementary school children. A national survey was performed in 2010 to collect data on food intake frequency, understanding of nutrition labeling, and body mass index from 2,335 fifth grade students in 118 elementary schools selected from 16 metropolitan local governments by stratified cluster sampling. The data were analyzed using the SAS 9.1 and SUDAAN 10.0 packages. Students who consumed three meals for 6-7 days during the past week were classified into the regular meal eating (RM) group (n = 1,476) and those who did not were placed into the meal skipping (MS) group (n = 859). The daily intake frequency of fruits, vegetables, kimchi, and milk was significantly lower in the MS group compared to that in the RM group (P < 0.001), whereas the daily intake frequency of soft drinks and instant noodles (ramyeon) was significantly higher in the MS group than that in the RM group (P < 0.05). The MS group demonstrated a significantly lower degree of understanding with regard to nutrition labeling and high calorie foods containing low nutritional value than that in the RM group. The distribution of obesity based on the percentile criteria using the Korean growth chart was different between the MS and RM groups. The MS group (8.97%) had a higher percentage of obese subjects than that in the RM group (5.38%). In conclusion, meal skipping was related to poor food choice, low perception of nutrition labeling, and a high prevalence of obesity in Korean fifth grade children.

• Journal of the Korean Society of Food Culture
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• v.25 no.2
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• pp.109-116
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• 2010

Ramyen and Korean noodles (guksu) are popular foods in Korea and around the world. Since 1998, rice consumption in Korea has gradually decreased, whereas consumption of noodles has continuously increased. The purpose of this study is to assess the consumption of ramyen and Korean noodles of Koreans, using data from the Korean National Health and Nutrition Examination Survey (KNHANES) of 2007. Korean adults (>20) were selected to examine the associations between noodle consumption and food and nutrient intake and health status. SAS 9.1 and SUDAAN 9.1 were used for the data analysis. 10.3% of Korean adults consumed ramyen, and 15.4% consumed Korean noodles. The consumption of ramyen and Korean noodles were higher in men than in women, in lunch than in other meals, and in the lowest income quartile than the highest quartile. Ramyen and Korean noodle consumer groups consumed more grain products, seasonings, and oils than the nonconsumer group. The noodle group showed significantly lower systolic blood pressure than the non-consumer group. The noodle groups showed lower rates of hypertension and metabolic syndrome than the non-consumer group. From these results, we conclude that ramyen and Korean noodles may have positive health effects. More studies on the association between noodles and the health of Koreans and those in other countries should be done in the future.

• Korean Journal of Community Nutrition
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• v.21 no.6
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• pp.558-573
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• 2016

Objectives: The purpose of this study was to evaluate the main sources of dietary sodium and potassium intake in Koreans by gender, age and regions. Methods: We used the data from 2010-2012 KNHANES. A total of 20,387 subjects aged 8 years and older were included. Intakes were compared by gender, age (8-18, 19-49 and >50 years) and geographical regions in Korea. Dishes were classified into 28 dish groups based on cooking methods. Statistical analysis was performed by using the SAS 9.3 and SUDAAN 11.0.1 software. Results: The mean sodium intake of Koreans was $4866.5{\pm}35.9mg/day$, which was 2.4 times higher than the adequate intake (AI) of sodium for Koreans. We found that daily sodium intakes were significantly different by age, gender and regions. Men and aged over 50 years had significantly higher sodium intake than women and other age groups. The mean potassium intake in Koreans was $3002.2{\pm}19.4mg/day$ and daily potassium intakes were significantly different by age, gender and regions. Women and age 50 years and over had significantly higher potassium intakes than men and other age groups. The average Na/K ratio was $2.89{\pm}0.01$ and was highest in men and in the age group of 19-49 years. The major sources of dietary sodium were soup and stew, followed by Kimchi, noodles and dumpling, pickled vegetables and seasonings, which represented 63.1 % of total sodium intakes. Soup and stew or Kimchi were the primary sources of dietary sodium intake. The major sources of dietary potassium were cooked rice, followed by soup and stew, Kimchi, fruits and beverages. Conclusions: Sodium and potassium intakes and the major sources of those were significantly different by gender, age groups and regions. Therefore, different approaches based on gender, age and regions are needed to decrease sodium intake and increase potassium intake.