• Journal of Preventive Medicine and Public Health
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• v.43 no.6
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• pp.543-548
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• 2010

Objectives: The objective of this study was to calculate sample size and power in an ongoing cohort, Korea radiation effect and epidemiology cohort (KREEC). Method: Sample size calculation was performed using PASS 2002 based on Cox regression and Poisson regression models. Person-year was calculated by using data from '1993-1997 Total cancer incidence by sex and age, Seoul' and Korean statistical informative service. Results: With the assumption of relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, sample size calculation was 405 events based on a Cox regression model. When the relative risk was assumed to be 1.5 then number of events was 170. Based on a Poisson regression model, relative risk=1.3, exposure:non-exposure=1:2 and power=0.8 rendered 385 events. Relative risk of 1.5 resulted in a total of 157 events. We calculated person-years (PY) with event numbers and cancer incidence rate in the nonexposure group. Based on a Cox regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, 136 245PY was needed to secure the power. In a Poisson regression model, with relative risk=1.3, exposure:non-exposure=1:2 and power=0.8, person-year needed was 129517PY. A total of 1939 cases were identified in KREEC until December 2007. Conclusions: A retrospective power calculation in an ongoing study might be biased by the data. Prospective power calculation should be carried out based on various assumptions prior to the study.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7665-7671
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• 2014

Objectives: The association between body mass index (BMI) and ovarian cancer risk is unclear and requires further investigation. The present meta-analysis was conducted to assess the effect of overweight and obesity on ovarian cancer risk in the premenopausal and postmenopausal periods. Data sources: Major electronic databases were searched until February 2014 including Medline and Scopus. Reference lists and relevant conference databases were searched and the authors were contacted for additional unpublished references. Review Methods: All cohort and case-control studies addressing the effect of BMI on ovarian cancer were included, irrespective of publication date and language. The effect measure of choice was risk ratio (RR) for cohort studies and odds ratio (OR) for case-control studies. The results were reported using a random effects model with 95% confidence intervals (CIs). Results: Of 3,776 retrieved studies, 19 were ultimately analyzed including 10 cohort studies involving 29,237,219 person-years and 9 case-control studies involving 96,965 people. The results of both cohort and case-control studies showed being overweight and obesity increased the risk of ovarian cancer compared to women with normal weight during both premenopausal and postmenopausal periods: RR=1.08 (95%CI: 0.97, 1.19) and OR=1.26 (95%CI: 0.97, 1.63) for overweight and RR=1.27 (95%CI: 1.16, 1.38) and OR=1.26 (95%CI: 1.06, 1.50) for obesity. Conclusions: There is sufficient evidence that an increase in BMI can increase the risk of ovarian cancer regardless of the menopausal status, mimicking a dose-response relationship although the association is not very strong.

• Journal of International Area Studies (JIAS)
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• v.14 no.1
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• pp.309-330
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• 2010

This paper examines the life-cycle and birth cohort effect on East Asian supranational identity. This paper also explores how national identity is related with supranational identity among Koreans. Using the 2008 CCGA-EAI survey, we analyze the determinants of supranational East Asian identity. The results suggest several interesting findings. Age and national identity have positive effects on East Asian identity. Among generational cohorts, the democratization cohort were less likely than other cohorts to have East Asian identity. These findings suggest several implications. First, in Korea, unlike other countries in the Western world, the older tend to have stronger regional identity than the younger do. Second, unlike the existing literature, this paper finds that strong national identity (pride) is complementary, rather than substitutive, to supranational regional identity. This warrants further systematic research on the microfoundation on the relationship between regional integration and nationalism in Northeast Asia.

• Journal of the Korean Society of Food Culture
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• v.17 no.4
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• pp.435-445
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• 2002

The purpose of this study was to identify the pattern and perception of food consumption, mass restaurant use, drinking style, and food purchasing factors by cohort groups i. e., World Cup(W) generation, baby boom, and silent generation. Data were collected from 412 respondents including three generations by questionnaire method in April through May 2002. Analysis of variance and chi-square results indicate that there were significant differences among three generation groups for the pattern and perception of food consumption, the use of mass restaurant, preferred drinking style, and influencing factors for food purchasing. W generation are more likely to be influenced by sensibility factor than baby boom and silent generation. Considering food preference pattern, baby boom as well as silent generation prefer green vegetables than meats, and they must have Kimche when having meals. Similarities and differences in perceptional pattern types are discussed, and future implications for food and nutrition specialists and food marketers are provided.

• Journal of Digital Convergence
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• v.17 no.8
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• pp.429-437
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• 2019

This study examined diverse capital dynamics and the effect of the dynamics on the quality of life of Korean baby boomers living in Jeonju. Also this study investigated the moderating effect of birth cohort. A structural equation modeling conducted with 303 baby boomers for verification. The results are as follows: First, the human capital of baby boomer directly or indirectly affected psychological, economic, social capital, and quality of life. Second, economic capital directly or indirectly affected psychological, social capital, and quality of life. Third, psychological capital directly or indirectly affected social capital and quality of life. Fourth, social capital affected the quality of life. Fifth, the birth cohort moderated the impacts of economic capital on psychological capital and quality of life. The results provided an understanding of the quality of life of baby boomer and the direction of intervention.

• 한국노년학
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• v.30 no.4
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• pp.1225-1237
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• 2010

This study aims to analyze the factors affecting consumption inequality in the 10 years following the financial crisis, applying the cohort method on the data for the first to the eleventh wave of the Korean Labor and Income Study produced by the Korean Labor Institute. The study found that consumption inequality increased rapidly immediately following the financial crisis, and then decreased gradually until increasing again from 2005 onward. Analyzed in terms of age-time-cohort effects, there was a significant change in consumption inequality around the age of mid-forties, and the decrease in consumption inequality was smaller in the younger generations than in the older ones. This suggests that as the current younger generations age over time, consumption inequality may become greater. Also, when the factors in population-cohort-age effects from 1998 onward are analyzed, the age effect in consumption inequality becomes smaller, whereas the role of the rising average age due to demographic shifts seems to be increasing. This means that consumption inequality may become a serious problem in the rapidly aging society. Therefore, there is a need to consider ways to bolster social security and to provide further public assistance in the low-income retiree.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2991-2995
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• 2012

Background: India shows some of the highest rates of cervical cancer worldwide, and more than 70% of the population is living in rural villages. Prospective cohort studies to determine the risk factors for cervical cancer are very rare from low and medium resource countries. The aim of this study was to quantify the effect of risk factors related to cervical cancer in a rural setting in South India. Material and methods: Sociodemographic and reproductive potential risk factors for cervical cancer were studied using the data from a cohort of 30,958 women who constituted the unscreened control group in a randomised screening trial in Dindigul district, Tamilnadu, India. The analysis was accomplished with the Cox proportional hazard regression model. Results: Women of increasing age (HR=2.4; 95% CI: 1.6, 3.8 in 50-59 vs 30-39), having many pregnancies (HR=7.1; 1.0, 52 in 4+ vs 0) and no education (HR=0.6; 0.2, 0.7 in high vs none) were found to be at significantly increased risk of cervical cancer. Conclusion: This cohort study gives very strong evidence to say that education is the fundamental factor among the sociodemographic and reproductive determinants of cervical cancer in low resource settings. Public awareness through education and improvements in living standards can play an important role in reducing the high incidence of cervical cancer in India. These findings further stress the importance of formulating public health policies aimed at increasing awareness and implementation of cervical cancer screening programmes.

• Health Policy and Management
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• v.24 no.1
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• pp.35-46
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• 2014

Background: This paper describes the relationship and effect of health examination on personal medical cost by identifying the difference of the cost for medical care in physician visit between the population without and with health examination. Methods: After classifying into three cohorts in which, independent variables were designed according to the Andersen's behavioral model, the association of personal medical cost for medical care and prescription drugs which is dependent variable was analyzed by t-test and Mann-Whitney test for description and gamma regression model for inference. Results: In personal average medical cost, the population with health examination paid significantly more than without health examination, 11.6% more in cohort 2008, 26.6% more in cohort 2009, and 48.0% more in combined cohort. The odds ratio on medical expenditure of outpatients with health examination was 1.067, 1.126, 1.398 significantly in cohort 2008, 2009, and combined cohort respectively, comparing to the group without health examination. In independent variables, that is female, the elderly, never married, non-working, non-metropolitan, the higher family income, the smaller family size, people with disability, the people with chronic disease, and people with health examination have significantly being paid more tendency showing positive association with medical cost. Conclusion: This result showed that medical expenditure in physician visit has been increased after taking a health examination. Therefore reasonable limitation of getting preventive medical service is suggested to avoid medical shopping around and reduce being repeated health examination by unifying control to find out easily the clinical results from various medical facilities.

• Journal of Periodontal and Implant Science
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• v.42 no.3
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• pp.67-72
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• 2012

Purpose: Rheumatoid arthritis (RA) is a chronic multi-systemic disease that causes damage to the bone and connective tissues. This study was conducted in order to accurately measure the correlation between RA and periodontitis, and to obtain an unbiased estimate of the effect of RA on periodontal indices. Methods: In this historical cohort study, which was conducted from February to May 2011 in Hamadan city, Iran, 53 exposed people (with RA) were compared with 53 unexposed people (without RA) in terms of clinical periodontal indices (the outcomes of interest) including 1) plaque index (PI), 2) bleeding on probing (BOP), and 3) clinical attachment loss (CAL). Results: A sample of 106 volunteers were evaluated, 53 rheumatoid versus 53 non-rheumatoid subjects. There was a statistically significant correlation between RA and BOP (P<0.001) and between RA and CAL (P<0.001). However, there was no statistically significant correlation between RA and any of the periodontal indices. No correlation was seen between gender and any of the indices either. There was a strong positive correlation between age and all three periodontal indices (P<0.001). Conclusions: The present study indicated a potential effect of RA on periodontal indices. However, much more evidence based on a prospective cohort study is needed to support the cause and effect relationship between RA and periodontal indices.

• Journal of Distribution Science
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• v.16 no.9
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• pp.79-99
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• 2018

Purpose - Food consumption in Korea has changed in paradigm as it has grown qualitatively in the past in quantitative shortages. Consumer food consumption patterns are rapidly changing due to changes in economic, social and population conditions, scientific and technological development, climate change, and market opening. At the same time, there is a need to actively respond to these changes in terms of the food industry, market, and government policy. The purpose of this study is to examine the changes and characteristics of food consumption expenditure of Korean consumers in-depth and depth in order to provide implications for agriculture, food market and policymakers. Research design, data, and methodology - We analyzed various food consumption changes from the 1980s to 2015 through Household Income and Expenditure Survey raw data from MDIS(Microdata Integrated Service) of Statistics Korea. and conducted the age effect, generation effect, and year effect by cohort analysis. We also conducted comparisons with OECD countries on several indicators. Results - Food consumption spending was slow, and there was no significant change in home consumption, while eating out consumption increased about 20 times in 2015 compared to 1980. Income, age, residential area, number of household members showed significant changes in food consumption. According to the cohort analysis, the changes in the food consumption structure are largely due to age effect, and the year, age, and generation effects are different for each food item. Conclusions - Food consumption has a significant impact on not only the nutritional status of consumers but ultimately the public health. Therefore, they should be regarded as a strategic policy area of central government rather than a matter of size and change of food consumption expenditure.