• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1547-1555
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• 2015

We study the problem of nonignorable nonresponse in a two-way contingency table and there may be one or two missing categories. We describe a nonignorable nonresponse model for the analysis of two-way categorical table. One approach to analyze these data is to construct several tables (one complete and the others incomplete). There are nonidentifiable parameters in incomplete tables. We describe a hierarchical Bayesian model to analyze two-way categorical data. We use a nonignorable nonresponse model with Bayesian uncertainty analysis by placing priors in nonidentifiable parameters instead of a sensitivity analysis for nonidentifiable parameters. To reduce the effects of nonidentifiable parameters, we project the parameters to a lower dimensional space and we allow the reduced set of parameters to share a common distribution. We use the griddy Gibbs sampler to fit our models and compute DIC and BPP for model diagnostics. We illustrate our method using data from NHANES III data to obtain the finite population proportions.

• Journal of Integrative Natural Science
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• v.5 no.3
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• pp.157-162
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• 2012

Measurement error is one of main source of error in survey. It is generally defined as the difference between an observed value and an underlying true value. An observed value with error may be expressed as a function of the true value plus error term. In some cases, the measurement error variance may be also a function of the unknown true value. The error variance function can be rewritten as a function of true value multiplied by a scale factor. This research explore methods for estimation of the measurement error variance based on the data from complex sampling design. We consider the case in which the variance of mesurement error is a linear function of unknown true value, and the error variance scale factor is small. We applied our results to the U.S. Third National Health and Nutrition Examination Survey (the U.S. NHANES III) data for empirical analyses, which has replicate measurements for relatively small subset of initial respondents's group.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.53-59
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• 2013

Purpose: This study calculated the prevalence of cataract in Korean and examined corrected eyesight with different types of opacification of crystalline lens. Methods: Using the data of the national health and nutrition examination survey (NHANES), population-based and cross-sectional research were designed in this study. After dividing total 4,977 persons into different groups by age, from 40 to 95 and by sex, the prevalence of cataract with different types of opacification was investigated. The average age of the total subjects was $58.28{\pm}12.07$, and the number of men and women were 2,142(43.0%) and 2,835(57.0%), repectively. Eyesight was calculated when it was less than 0.63. Results: Among total 4,977 subjects, 40.6% (men 17.5%, women 23.1%) had cataract. Different prevalence rates were found with different types of cataract; nuclear cataract (56.3%), cortical cataract (23.4%), mixed cataract (16.2%), anterior subcapsular(3.0%), and posterior subcapsular (1.1%) in order. There was no difference among men and women by the types. And those in their 40's showed a higher prevalence of cortical cataract than those in the other age groups. Most of subjects whose corrected eyesight is less than 0.63 had anterior subcapsular cataract. Conclusions: The type of cataract having the highest prevalence was nuclear opacity. Moreover, epidemiologic investigation and prevention policy with different type of lens opacity seems to be required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.617-626
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• 2015

This study examined the relationship between the physical activity levels and health care utilization in Korean elderly based on the data from The fifth Korean National Health and Nutrition Examination Survey (K-NHANES V). As a result, physically active participants were 0.54 times (OR;95% CI, p<0.001) less likely to use inpatient health care and 0.73 times (OR;95% CI, p=0.040) less likely to use outpatient health care and 0.75 times (OR;95% CI, p<0.007) less likely to use drugstores than physically inactive participants, and the frequency of health care use was lower. In addition, physically minimal active participants were 0.64 times (OR;95% CI, p<0.001) less likely to use inpatient health care than physically inactive participants; the frequency of other health care facilities was lower. In conclusion, the relationship between being physically active and lower health care utilization among Korean elderly identified in this study. This suggests that being physically active is helpful to the elderly, not only in health promotion and improving quality of life, but also in reduced medical expenditure.

• Journal of the Korean Dietetic Association
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• v.19 no.1
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• pp.46-58
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• 2013

Calcium intake has been insufficient in all age groups in previous Korean national surveys. This study was conducted to investigate calcium intake in Korean and American populations at different ages. We analyzed two national survey data: the 2007~2009 Korean National Health and Nutrition Examination Survey (KNHANES) and the 2007~2008 National Health and Nutrition Examination Survey (NHANES). Statistically, survey procedures were applied using the weight, cluster, and strata variables. The mean calcium intake of Koreans at ages of 1~2 y, 3~5 y, 6~11 y, 12~18 y, 19~64 y, and 65+y was lower than American populations at those ages. The sufficient proportions based on Korean Estimated Average Requirement (EAR) of 1~2 y, 3~5 y, 6~11 y, 12~18 y, 19~64 y, and 65+y in Koreans were 45.5%, 33.1%, 24.3%, 16.6%, 32.7%, and 19.0%. While the sufficient rates based on American EAR of 1~3 y, 4~8 y, 9~13 y, 14~18 y, 19~30 y, 31~50 y, 51~70 y, and 71+y in US population were 88.5%, 54.4%, 35.2%, 35.8%, 55.3%, 55.2%, 40.6%, and 24.5%. Overall, the major foods contributing to calcium intakes in Koreans were milk, baechukimchi, and anchovies, whereas, milk products, pasta, or bread were major contributions to calcium in American populations. The calcium supplement intakes in the American population were 5.5 mg (1~2 y), 15.5 mg (3~5 y), 13.9 mg (6~11 y), 35.7 mg (12~18 y), 150.3 mg (19~64 y) and 334.4 mg (${\geq}65$ y). These results suggest that Korean adolescents and older adults are the most insufficient in dietary calcium intakes among Koreans. In order to accurately estimate calcium intakes in Korean populations, calcium supplements and calcium-fortified foods should be considered.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.493-498
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• 2014

Purpose: This study utilized the Geographic Information System (GIS) which is one of the representative methods for describing visual distribution, to show the distribution of visions of middle and high school students in 16 cities or provinces in Korea. Method: The data of National Health and Nutrition Examination Survey (NHANES) were analysed from 2009 to 2011 and designed a population-based cross-sectional study. The subjects were total 1,049 students at the age of 13 to 18 and uncorrected vision was provided. Male subjects were 549 (52.3%) and female subjects were 500 (47.7%). Subjects were divided into 16 cities or provinces and average vision of regions were analysed. the differentials of vision among the regions were analysed by as a spatial analysis method. Results: The average uncorrected vision were significant difference by sex (p=0.001). However male and female student groups' average vision indicated no statistically significant difference by region in those 16 cities and provinces. In order to show the differentials of middle and high school students' vision by region with a visual distribution method, the GIS was utilized for mapping. Conclusions: The differentials of vision among regions by GIS provide a visually effective distribution map.

• Journal of Nutrition and Health
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• v.38 no.10
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• pp.856-863
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• 2005

Dietary Variety Score (DVS) or Nutrient Adequacy Ratio (NAR) offers a way of comparing eating habits across populations and across countries. This study compared nutrients intakes, food intakes, DVS, and NAR between Korean and US adults using the large national survey data. 4662 Korean adults (men: 2201, women: 2461) aged 20-49 years were selected from the 'Korean National Health and Nutrition Survey,2001' and 4199 US adults (men: 2127, women: 2072) aged 20-49 years were selected from the 'US National Health and Nutrition Examination Survey (NHANES IV,1999-2002)'. The total plant food intakes were high in Korean adults, but the total animal food intakes were high in US adults. Intakes of legumes and nuts, vegetables and mushrooms were higher in Korean than in US adults. On the other hand, intakes of meats, milk and dairy products of US adults were higher than Korean. Beverage intakes were 8 - 10 times higher in US adults than in Korean. The mean DVS of Korean men and women were higher than US men and women. Intakes of fat, calcium and vitamin $B\_{2}$ of US adults were 1.5 - 2 times higher than those of Korean, which could probably related to larger consumption by US adults on milk and dairy product. While the intakes of carbohydrate and vitamin C of the Korean were higher than the US adults, which could presumably related to higher grain and vegetable consumption. Percent energy intakes from carbohydrate, protein, and fat were $64.1\%$, $15.8\%$, and $20.1\%$ for Korean men, $52.4\%$, $15.0\%$, and $32.6\%$ for US men, $65.9\%$, $14.9\%$, $19.2\%$ for Korean women, and $52.1\%$, $14.7\%$, $33.2\%$ for US women respectively, which showed higher $\%$energy from carbohydrate in Korean and higher $\%$energy from fat in US adults. Most nutrient intakes except energy and vitamin C expressed as $\%$RDA were higher in US than in Korean adults. Mean Adequacy Ratio (MAR) of US men and Korean men were both 0.85, while the MAR was 0.81 for Korean women,0.79 for US women. The Korean women's diet showed more diverse and adequate than the US women's diet.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.416-423
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• 2022

This study was a secondary data analysis study to determine the relationship between mental health counseling and the current prevalence of depression in the Korean adult population. Data were extracted from raw data of the 7th 3rd year (2018) of the National Health and Nutrition Examination Survey (NHANES) conducted by the Korea Centers for Disease Control and Prevention. The subjects of this study were 6,238 adults aged 19 years or older who participated in the NHANES conducted from January to December 2018. The collected data were analyzed by frequency analysis and logistic regression analysis of the complex sample by the SPSS/WIN 27.0 version program. The mental health counseling statistically significant associated with variables such as sex, marital status, economic activities, and family income level, respectively (p<0.05). The prevalence of depression statistically significant associated with age group (p<0.0001). The odds-ratio of current prevalence of depression was 5.09 times (OR, 5.085; p<0.0001) lower in subjects who had undergone mental health counseling for the past year compared to subjects who did not. These findings could be useful as evidence-based data for the prevention and management of depression by predicting the vulnerable factors for mental health in the Korean adult population.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.1
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• pp.27-39
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• 2024

Purpose : Smoking is a major factor in chronic obstructive pulmonary disease (COPD), but the effect of electrical cigarette smoking on COPD development is still uncertain. This study aimed to compare the functions of airways and lungs exposed to combustible cigarettes and electrical cigarettes based on the pulmonary function test (PFT) results from the Korean National Health and Nutrition Examination Survey (NHANES). Methods : This study used data from 8,942 participants with PFT results out of 47,309 total subjects from the 6th to 8th Korean NHANES (2014-2015, 2016-2018, and 2019, respectively). Individuals with diseases such as cancer, ex-smokers, and dual tobacco users were excluded. The PFT results were analyzed according to the COPD diagnostic criteria. After adjusting for confounding variables, a complex sample generalized linear model ANOVA test was performed to investigate the association between PFT results and combustible smoker or electrical cigarette user groups. Results : In an analysis based on the obstructive ventilatory disorders (forced expiratory volume in 1 second[FEV₁]/forced vital capacity[FVC]<.7), combustible cigarette smokers showed a 3.46 times higher risk of COPD compared to non-smokers, while electrical cigarette smokers exhibited no significant difference in terms of COPD-related risks compared to non-smokers. FEV₁ showed a negative relation with combustible cigarette smokers as reported elsewhere (B=-.07, p<.001). FEV₁/FVC was negatively related to both combustible cigarette smokers (B=-.03, p<.001) and electrical cigarette smokers (B=-.02, p<.001). Conclusion : FEV₁/FVC decreases were observed in the long-term exposure to both combustible and electrical cigarettes. The lower FEV₁ in the combustible cigarette group implies the worsening of the severity of COPD, suggesting more damage to the airways and lungs in the short term. Therefore, the temporary electrical cigarettes use for the transition period in order to smoking cessation potentially aids to reduce the harmful effect of combustible cigarettes in COPD development.

• Proceedings of the Korean Association for Survey Research Conference
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• 2003.06a
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• pp.34-41
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• 2003

In many cases, the measurement error variances may be functions of the unknown true values or related covariates. This paper develops estimators of the parameters of a linear measurement error variance function based on wi thin-unit sample variaoces. This paper devotes to: (1) define measurement error scale factor $\delta$: (2) develop estimators of the parameters of the 1inear measurement error variance function under stratified multistage sampling design and small error conditions; (3) use propensity methods to adjust survey weights to account for possible selection effects at the replicate level. The proposed methods are applied to medical examination data from the U S Third National Health and Nutrition Examination Survey(NHANES III)