• Korea journal of population studies
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• v.11 no.1
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• pp.97-116
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• 1988

This study examines the socioeconomic determinants of fertility behavior in Korea by developing a model which simultaneously takes into account both individual and community-level differences. It especially focuses on the micro-macro nexus of fertility behavior depending on social contexts. This study utilizes micro data obtained from the 1974 Korean National Fertility Survey(KNFS), and macro data obtained from Korean government statistics. The framework of the model is formalized as a set of structural equations modelling the fertility process. The model is formed on a cohort-specific processual basis and is restricted to five-year birth cohorts. Three cohorts of women are studied : those aged 30-34, 35-39, and 40-44. The model includes three fertility-process components : age at first birth, early fertility, and later fertility, which are defined by reference to the age of the mother. The results of this study indicate that socioeconomic development in Korea results in increased age at first birth and reduced numbers of children per couple. In addition to the developmental change, Korea's fertility decline is found to be facilitated by family planning programs. As expected, the effect of family planning on fertility is greater among better-educated women than among poorly educated women. The inconsistent but suggestive result, however, is that the effect of socioeconomic development on fertility is greater among less-privileged women than among more-previleged women.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.127-134
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• 2022

Objective: This study aimed to investigate the impact of hyperandrogenism (HA) on the outcomes of ovulation induction (OI) using gonadotropin and intrauterine insemination (IUI) in patients with polycystic ovary syndrome (PCOS). Methods: This was a retrospective cohort study including 415 patients undergoing OI using gonadotropin and IUI treatment between January 2018 and December 2020 at a single infertility center. Baseline characteristics, clinical and laboratory parameters, and pregnancy outcomes were investigated. Results: Among the study population, there were 105 hyperandrogenic (25.3%) and 310 non-hyperandrogenic patients (74.7%). The live birth rate was lower in the HA group than in the non-HA group, but this difference did not reach statistical significance due to the limited sample size (14.3% vs. 21.0%, relative risk=0.68; 95% CI, 0.41-1.14, p=0.153). No predictive factors for live birth were identified through logistic regression analysis. Conclusion: HA did not negatively affect the outcomes of OI using gonadotropin and IUI cycles in Vietnamese women with PCOS. The result may not be applicable elsewhere due to the large variation in the characteristics of women with PCOS across races and populations.

• Journal of Korean Academy of Nursing
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• v.47 no.3
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• pp.357-366
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• 2017

Purpose: The aim of this study was to determine the influence of various factors on preterm labor symptoms (PLS) and preterm birth (PB). Methods: This prospective cohort study included 193 women in the second stage of pregnancy. Multiple characteristics including body mass index (BMI), smoking, and pregnancy complications were collected through a self-report questionnaire. Pregnancy stress and PLS were each measured with a related scale. Cervical length and birth outcome were evaluated from medical charts. Multiple regression was used to predict PLS and logistic regression was used to predict PB. Results: Multiple regression showed smoking experience, pregnancy complications and pregnancy specific stress were predictors of PLS and accounted for 19.2% of the total variation. Logistic regression showed predictors of PB to be twins (OR=13.68, CI=3.72~50.33, p<.001), shorter cervix (<25mm) (OR=5.63, CI=1.29~24.54, p<.05), BMI >25 ($kg/m^2$) (OR=3.50, CI=1.35~9.04, p<.01) and a previous PB (OR=4.15, CI=1.07~16.03, p<.05). Conclusion: The results of this study show that the multiple factors affect stage II pregnant women can result in PLS or PB. And preterm labor may predict PB. These findings highlight differences in predicting variables for pretrm labor and for PB. Future research is needed to develop a screening tool to predict the risk of preterm birth in pregnant women.

• Korean Journal of Adult Nursing
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• v.18 no.1
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• pp.146-156
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• 2006

Purpose: 1) to construct cohorts according to risk scores calculated with the Gail Breast Cancer Risk Assessment Tool (Gail et al., 1989) (Gail) and the Breast Cancer Risk Appraisal (Lee et al,. 2003) (Lee) 2) to identify the distribution of risk factors and preventive behavior stages between the cohorts 3) to identify abnormal breast conditions in risk cohort. Method: Using convenience sampling, 775 rural women were selected. Risk appraisal was scored using Gail and Lee. Preventive behavior stages for BSE (Breast self examination) and mammography were measured using 4 stages of the Transtheoretical Model (Prochaska & DiClemente, 1983). Results: 1) The risk cohort according to Gail was 12.3% (n=95), and Lee, 3.1% (n=24). 2) There were significant differences in the distribution of risk factors (age, family history, age at 1st live birth, age at menarche, number of breast biopsy, history of breast disease, and breast-feeding) between cohorts. 3) There was a significant difference in the distribution of the stage of BSE according to Lee. 4) Six women in the risk group detected masses or nodules and physician consultation and ultrasonography were recommended. Conclusion: On the basis of the constructed cohorts, further longitudinal studies of cohorts are recommended with interventions according to characteristics of cohorts.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4501-4504
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• 2012

In recent decades, decreasing trends in esophageal cancer mortality have been observed across China. We here describe esophageal cancer mortality trends in Linzhou city, a high-incidence region of esophageal cancer in China, during 1988-2010 and make a esophageal cancer mortality projection in the period 2011-2020 using a Bayesian approach. Age standardized mortality rates were estimated by direct standardization to the World population structure in 1985. A Bayesian age-period-cohort (BAPC) analysis was carried out in order to investigate the effect of the age, period and birth cohort on esophageal cancer mortality in Linzhou during 1988-2010 and to estimate future trends for the period 2011-2020. Age-adjusted rates for men and women decreased from 1988 to 2005 and changed little thereafter. Risk increased from 30 years of age until the very elderly. Period effects showed little variation in risk throughout 1988-2010. In contrast, a cohort effect showed risk decreased greatly in later cohorts. Forecasting, based on BAPC modeling, resulted in a increasing burden of mortality and a decreasing age standardized mortality rate of esophageal cancer in Linzhou city. The decrease of esophageal cancer mortality risk since the 1930 cohort could be attributable to the improvements of socialeconomic environment and lifestyle. The standardized mortality rates of esophageal cancer should decrease continually. The effect of aging on the population could explain the increase in esophageal mortality projected for 2020.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.323-330
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• 2001

Objective : To examine the association between age at menopause and mortality in a population-based sample of women in Kangwha, Korea. Methods : From the Kangwha Cohort, followed-up from 1985 to 1999, the data of the over 55 year old female group(n=3,596) was used in this study to examine the association between age at menopause and mortality. We calculated the all causes mortality risk ratio and the cancer mortality risk ratio by age at menopause grouping using the Cox Proportional Hazards Model with adjustments for age, BMI, smoking, education, chronic disease, self-rated health status, alcohol consumption and age at first birth. Result and conclusion : Compared to women who had menopause at 45-49 years, the all causes mortality risk ratio was 1.24 for women with menopause at less than 40 years(95% CI=1.01-1.53) and 1.05 for women with menopause at over 50 years(95% CI=0.92-1.20). Also, compared to women who had menopause at 45-49 years, the cancer mortality risk ratio was 1.53 for women with menopause at less than 40 years(95% CI=0.78-2.98) and 1.17 for women with menopause at over 50 years(95% CI=0.77-1.80).

• 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 Preventive Medicine and Public Health
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• v.43 no.5
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• pp.369-376
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• 2010

Objectives: The purpose of this study was to examine the associations of current body weight and body mass index (BMI) at age three and birth weight in developing chronic respiratory illness in childhood and identify possible interaction underlying its mechanism. Methods: The study was carried out with 422 children who were enrolled in a hospital-based birth cohort. Birth related anthropometric data were collected at birth. At age 3 years, the presence of respiratory symptoms was evaluated by using the Korean version of core questionnaire for wheezing and asthma from the International Study of Asthma and Allergies in Childhood (ISAAC). Physical examination was carried out to measure the child's weight and height. Results: Children in the lowest birth weight tertile (aOR = 3.97, 95% CI = 0.94-16.68) or highest BMI tertile (aOR = 3.68, 95% CI = 1.24-10.95) at three years of age were at an increased risk of chronic respiratory illness. Children who were initially in the lowest birth weight tertile but now belong in the highest weight tertile had higher risk of chronic respiratory illness compared to those who had remained in the middle tertile (OR=16.35, 95% CI=1.66-160.57). Conclusions: Children with lower birth weight or higher BMI were at an increased risk of chronic respiratory illness. In addition, children who were initially in the lowest birth weight tertile but are now in the highest weight tertile had higher risk of chronic respiratory illness compared to those who remained in the middle tertile.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.4
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• pp.366-376
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• 2020

Purpose: To assess the association between birth weight and the development of functional gastrointestinal disorders (FGIDs) in the first year of life. Methods: This is a secondary analysis of a prospective cohort multicenter study including neonates, consecutively enrolled at birth, and followed up for one year. At birth all infants were classified by birth weight as extremely low (ELBW), very low, or low when <1,000, <1,500, and <2,500 g, respectively, and by birth weight for gestational age as appropriate (AGA, weight in the 10-90th percentile), small (SGA, weight <10th percentile), and large (LGA, weight >90th percentile) for gestational age. FGIDs were classified according to the Rome III criteria and assessed at 1, 3, 6, and 12 months of life. Results: Among 1,152 newborns enrolled, 934 (81.1%) completed the study: 302 (32.3%) were preterm, 35 (3.7%) were ELBW, 104 (11.1%) were SGA, 782 (83.7%) were AGA, and 48 (5.1%) were LGA infants. Overall, throughout the first year of life, 718 (76.9%) reported at least one FGID. The proportion of infants presenting with at least one FGID was significantly higher in ELBW (97%) compared to LBW (74%) (p=0.01) and in LGA (85.4%) and SGA (85.6%) compared to AGA (75.2%) (p=0.0001). On multivariate analysis, SGA was significantly associated with infantile colic. Conclusion: We observed an increased risk of FGIDs in ELBW, SGA, and LGA neonates. Our results suggest that prenatal factors determining birth weight may influence the development of FGIDs in infants. Understanding the role of all potential risk factors may provide new insights and targeted approaches for FGIDs.

• Clinical and Experimental Pediatrics
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• v.62 no.10
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• pp.386-394
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• 2019

Background: Preterm infants have difficulty maintaining body temperature after birth. However, clinical guidelines advocate that neonatal body temperature should be maintained at 36.5℃-37.5℃. Purpose: We aimed to investigate the incidence of admission hypothermia in very low birth weight (VLBW) infants and to determine the association of admission temperature with in-hospital mortality and morbidities. Methods: A cohort study using prospectively collected data involving 70 neonatal intensive care units (NICUs) that participate in the Korean Neonatal Network. From registered infants born between January 2013 and December 2015, 5,343 VLBW infants born at less than 33 weeks of gestation were reviewed. Results: The mean admission temperature was 36.1℃±0.6℃, with a range of 31.9℃ to 38.4℃. Approximately 74.1% of infants had an admission hypothermia of <36.5℃. Lower birth weight, intubation in the delivery room and Apgar score <7 at 5 minutes were significantly related to admission hypothermia. The mortality was the lowest at 36.5℃-37.5℃ and adjusted odd ratios for all deaths increased to 1.38 (95% confidence interval [CI], 1.04-1.83), 1.44 (95% CI, 1.05-1.97) and 1.86 (95% CI, 1.22-2.82) for infants with admission temperatures of 36.0℃-36.4℃, 35.0℃-35.9℃, and <35.0℃, respectively. Admission hypothermia was also associated with high likelihoods of bronchopulmonary dysplasia, pulmonary hypertension, proven sepsis, pulmonary hemorrhage, air-leak, seizure, grade 3 or higher intraventricular hemorrhage and advanced retinopathy of prematurity requiring laser therapy. Conclusion: A large portion of preterm infants in Korea had hypothermia at NICU admission, which was associated with high mortality and several important morbidities. More aggressive interventions aimed at reducing hypothermia are required in this high-risk population.