• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.456-460
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• 2005

The purpose of this study is to develop a estimation model of migration with only population data using the cohort-survival model which has been used for forecasting future population. The fluctuation of population can be bisected to the natural change which can be occurred by birth and death and the social change which means migration. The factors of the social change are usually very important for establishing rural policies. However, researches using migration data has limitations because the usage of them are restricted. For verifying a estimation model of migration, comparing estimated population in 2000 year and migration quantity between 1996 and 2000 of 25 gu with real values, using population data and death ratio from 1995 to 2000 of the 25 gu in Seoul. Result shows a reliable data that R-square of forecating population model is 0.9755 and migration is 0.9180. So these model are worth to estimate a population and migration quantity to restricted migration data.

• Clinical and Experimental Pediatrics
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• v.55 no.8
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• pp.259-264
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• 2012

Wheezing is one of the most frequent complaints that lead to the use of medical resources in younger children. Generally, wheezing is caused by bronchiolitis and resolves spontaneously without recurrence, but sometimes, wheezing can progress into asthma. Early data on the natural history of childhood wheezing was mostly obtained from retrospective reviews of medical records or from questionnaires, which made it difficult to exclude biases. Now that many cohort studies are available, reviewing the results of birth cohort studies makes it possible to understand the natural course of early childhood wheezing and the risk factors for asthma. In this study, we have reviewed the various phenotypes of early childhood wheezing and their natural courses to help select the most appropriate management modalities for the different types of early childhood wheezing.

• Journal of Preventive Medicine and Public Health
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• v.52 no.3
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• pp.188-194
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• 2019

Objectives: Outbreaks of scarlet fever in Mexico in 1999, Hong Kong and mainland China in 2011, and England in 2014-2016 have received global attention, and the number of notified cases in Korean children, including in Jeju Province, has also increased since 2010. To identify relevant hypotheses regarding this emerging outbreak, an age-period-cohort (APC) analysis of scarlet fever incidence was conducted among children in Jeju Province, Korea. Methods: This study analyzed data from the nationwide insurance claims database administered by the Korean National Health Insurance Service. The inclusion criteria were children aged ${\leq}14years$ residing in Jeju Province, Korea who received any form of healthcare for scarlet fever from 2002 to 2016. The age and year variables were categorized into 5 groups, respectively. After calculating the crude incidence rate (CIR) for age and calendar year groups, the intrinsic estimator (IE) method was applied to conduct the APC analysis. Results: In total, 2345 cases were identified from 2002 to 2016. Scarlet fever was most common in the 0-2 age group, and boys presented more cases than girls. Since the CIR decreased with age between 2002 and 2016, the age and period effect decreased in all observed years. The IE coefficients suggesting a cohort effect shifted from negative to positive in 2009. Conclusions: The results suggest that the recent outbreak of scarlet fever among children in Jeju Province might be explained through the cohort effect. As children born after 2009 showed a higher risk of scarlet fever, further descriptive epidemiological studies are needed.

• Korea journal of population studies
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• v.14 no.1
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• pp.55-69
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• 1991

The objective of the study is to figure out the status of reproductive health and general characteristics related to maternal health for Korean-Americans living in Los Angeles. We collected data from the married women who wanted no more additional child birth and were attending the Family Planning Clinic of Koryo Health Foundation in Los Angeles during 1988. There were 494 women met the eligibility requirement for this study. The results are summarized below. 1. In the age distribution of the women who desired no more additional child birth, women 30-34 age group constituted the largest proportion at 36.6 percent ; the mean age of women was 35.1915.55. The mean number of child birth was 1.77, and the proportion of the women by number of child birth were 35.2 percent for one children, 50.1 percent for two children 10.5 percent for three children, and 2.6 percent for four children. All of the women experienced pregnancy at least once, and mean number of pregnancy was 3.42. The mean number of total experience of induced abortion was 1.56. and 76.7 percent of these women had experience with induced abortions. To prevent further pregnancies, 90.1 percent of the women were utilizing the contraceptive methods, and the highest proportion by the contraceptive methods was condoms(53.7%), 9.3 percent in spermicides, 8.7 percent in IUDs, 8.7 percent in rhythm method, and 6.9 percent in oral pills. 2. The mean age of women at each stage of reproductive life cycle were 14.74 years at time of menarche, 24.55 years at time of marriage, 26.60 years at time of the first child birth, and 28.75 years at time of the last child birth. In age distribution of the women by birth cohort (Group I : birth cohort 1940-1954, Group H : birth cohort 1955-1970), the mean menar-cheal age of the women was 14.96 years in group I , and 14.53 years in group H . Mean age at time of marriage was 25.01 years in group I and 24.08 years in group H . Mean child birth age of the women by birth cohort was 27.19 years In group I and 26.01 years in Group II for the first child birth and 30.07 years in group I and 27.45 years in group II for the last child birth. The total length of reproductive life cycle from menarche to menopause (presumed to be at 49 of age years) was 34.26 years. The len-gth of phase I (from menarche to marriage) was 9.81 years, while phase H (marriage to first birth) was 2.05 years, and phase Ill (first birth to last birth) was 2. 15 years, and the last phase of reproductive life cycle, phase IV (last birth to menopause) was 20.25 years. The proportion of each phase 10 total length of reproductive life cycle was 28.6 percent, 6.0 percent 6.3 percent, and 59.t percent respectively. In the tendency of each phase in reproductive life cycle by birth cohort (group I , U ), the length of phase I, II , III of birth cohort group II was diminished in comparison with those of birth cohort group I , but the length of phase IV was extended by 2.38 years. 3. Among the women, the mean number of total pregnancy by birth cohort group was 2.01 in group I and 1.10 in Group II, and mean number of child birth was 1.97 in group I and 1.58 in group II. In terms of pregnancy was-tage rate by birth cohort group, among the total pregnancy of birth cohort group I , 51.8 percent of the cases resulted in induced abortions or spontaneous abortions whils 48.2 percent resulted in live births, and 42.2 percent or total pregnancy in group II resulted in pregnancy wastage and 57.8 percent of the cases resulted in live births.

• Nutritional Sciences
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• v.6 no.3
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• pp.173-184
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• 2003

Objective : This study was carried out to develop a semi-quantitative food frequency Questionnaire (SQFFQ) for estimating average dietary intake to determine the risk factor for lifestyle-related diseases in a conjoint cohort study. Design : We developed an SQFFQ for genomic epidemiological studies based on the data in the'98 Korea Health and Nutrition Examination Survey. A subset of data on informative food items was collected using the 24-hr recall method with 2,714 adults aged 40 or older living in middle-sized cities or in rural areas in Korea. The cumulative percent contribution and cumulative multiple regression coefficients of 17 nutrients (energy, fat, carbohydrate, protein, fiber, iron, potassium, sodium, calcium, phosphorus, vitamin A, retinol, $\beta$-carotene, vitamin $B_1$, vitamin $B_2$, niacin and vitamin C) of each food were computed. Results : Two hundred and forty-nine foods, which were selected based on their 0.9 cumulative percent contribution, and 254 foods, which were selected based on their 0.9 cumulative multiple regression coefficients, respectively, were grouped into 97 food groups according to their nutrient contents. Several popular Korean foods, which were missing from the list due to the seasonality of the survey, were included. The portion sizes were derived from the same data set. The SQFFQ covered 84.8 percent of the intake of 17 nutrients in the one day diet record data of our 326 cohort study subjects. Conclusions . The final list included 103 food items. The foods list in the SQFFQ described herein accounted for 84.8 percent of the average intake of 17 nutrients. Therefore, the list could be used for the assessment of the baseline dietary intakes of the conjoint cohort studies.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.749-754
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• 2016

Extended follow-up of Hodgkin lymphoma (HL) survivors indicates that these patients are at high risk of secondary malignant neoplasms (SMNs) contributing to increased morbidity and mortality. This study examined the characteristics of HL survivors who developed SMNs with the aim to report any correlation with radiotherapy (RT) dose. In this retrospective multi-center cohort study of HL patients treated between 1990 and 2011 at three major teaching hospitals in Lebanon, classification was into two groups including those treated with combined modality (RT and chemotherapy-CHT) and those treated with CHT alone. Approval from the University Institutional Review Board (IRB) was obtained. Of the 112 patients evaluated, 52.7% (59) received the combined modality while 47.3% (53) received CHT alone. There were 6 cases of SMNs in the combined modality cohort and 5 cases in the CHT cohort. The mean RT dose in the combined modality cohort was 34.5 Gray (Gy) ($SD{\pm}5.3$). A statistically significant increase (1.5 fold) in the risk of developing SMNs was observed among patients who received a dose higher than 41 Gy compared to a dose between 20 to 30 Gy (OR= 1.5; 95% confidence interval= 0.674 to 3.339, p=0.012). The risk of SMNs was not significantly higher among patients who received extended field compared to involved field RT (p=0.964). This study showed that the risk of developing SMNs is higher among patients treated with RT dose greater than 31 Gy, independent of the RT type used.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.275-279
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• 2013

Objectives: A number of studies have shown that chronic hepatitis B virus infection is implicated in susceptibility to pancreatic cancer. However, the results are still controversial. This meta-analysis aimed to quantitatively assess the relationship between chronic hepatitis B virus infection and incidence of pancreatic cancer of cohort and case-control studies. Methods: A literature search was performed for entries from 1990 to 2012 using PUBMED and EMBASE. Studies were included if they reported odds ratios (ORs) and corresponding 95% CIs of pancreatic cancer with respect to the infection of hepatitis B virus. Results: Eight studies met the inclusion criteria, which included five case-control studies and three cohort studies. Compared with individuals who have not infection of hepatitis B virus, the pooled OR of pancreatic cancer was 1.403 (95%CI: 1.139-1.729, P=0.001) for patients with hepatitis B virus infection. Sub-group analysis by study design showed that the summary OR was 1.43 (95%CI: 1.06-1.94, P=0.021) when pooling case-control studies and 1.31 (95%CI: 1.00-1.72, P=0.05) when pooling cohort studies. Conclusion: Findings from this meta-analysis suggest that chronic hepatitis B virus infection may increase the risk of pancreatic cancer. This relationship needs to be confirmed by further follow-up studies.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.390-399
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• 1991

The purpose of this study is to examine the relationship between pesticide use and mortality, and cancer mortality which are recognized as health hazards of pesticides. Data were analyzed from a cohort of 6,066 people aged fifty-five or over and who have been residing in the main island of Kangwha county. Death certificates, computerized citizenship registers searches, and household interview survey lead to get more than ninety-seven percents follow-up rate for the first five year observation period. Important findings are as follows : 1. Age specific mortality rates of pesticide users are significantly lower than those of pesticides nonusers. The SMR of male is 0.80, and 0.58 for females respectively probably due to healthy worker effects. But, age specific cancer mortality rates are significantly higher than those of pesticide nonusers (SMR=1.59) in males. This finding is not observed in females (SMR=0.85), however. 2. Logistic regression analyses showed that self-reported health status, drinking, and smoking histories in male are significantly associated with total mortality rate. The histories of pesticide use are also calculated to be highly associated with cancer mortality as in univariate analyses in males. In female, self-reported health status, age of first delivery are found to be significantly related to total mortality rate. Only drinking history is calculated to be associated with cancer mortalities in females. Data from further observation of 'Kangwha cohort' and indepth analyses of these are highly expected.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.120-128
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• 1987

To assess the proportion of spectacles-wearing and an aspect of familial aggregation of myoptic spectacles-wearing and to observe the birth cohort for myoptic spectacles-wearing, a nationwide self-administered questionnaire survey was conducted from March 11 to September 19, 1985 A probability sample of 13,346 persons was taken from 180 enumerated districts designated by the fifth nationwide tuberculosis prevalence survey from Korean Institute of Tuberculosis. The major findings of this survey are as follows: 1) Total of 62.5% of the study population lived in urban area whereas 37.5% lived in Eup-Myun area. There was statistically significant difference in age and sex distribution between two residential area. 2) The percentage of spectacles-wearing was 8.3% and among these, myoptic and hyperoptic spectacles were 6.0%, 2.3%, respectively. A total of 8.5% of the male study population wore spectacles and this was slightly higher than the female (8.0%). 3) Among the occupational groups, students were the highest myoptic spectacles-wearing group whereas professionals were the highest hyperoptic spectacles-wearing group. 4) The proportion of myoptic spectacles-wearing was higher in female students than in male students respectively 11.6%, 8.7%. There was an increasing tendency of spectacles-wearing as age increased. 5) The age-sex adjusted prevalence rate of myoptic spectacles-wearing by residential areas was 2 times higher in urban area than Eup-Myun area 6) A wearing of the myoptic spectacles in early age was observed in recent birth cohort than remote birth cohort. 7) There was a tendency of familial aggregation for myoptic spectacles-wearing. The proportion of myoptic spectacles-wearing was 6 times higher for those who had parents wearing spectacles. 8) 60.9% of the total myoptic spectacles-wearing persons received the eye-specialist's order and 44. 9% for the hyperoptic spectacles wearing.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3413-3418
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• 2015

Background: Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem. Objectives: The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection. Materials and Methods: The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires. Results: O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively. Conclusions: Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.