• Title/Summary/Keyword: Cohort Analysis

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Inference of Age Compositions in a Sample of Fish from Fish Length Data (개체군 체장자료를 이용한 연령조성 추정)

  • Kim, Kyuhan;Hyun, Saang-Yoon;Seo, Young Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.1
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    • pp.79-90
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    • 2018
  • Fish ages are critical information in fish stock assessments because they are required for age-structure models such as virtual population analysis and stochastic catch-at-age models, whose outputs include recruitment strengths, a spawning stock size (abundance or biomass), and the projection of a fish population size in future. However, most countries other than the developed countries have not identified ages of fish caught by fisheries or surveys in a consistent manner for a long time (e.g.,>20 years). Instead, data about fish body sizes (e.g., lengths) have been well available because of ease of measurement. To infer age compositions of fish in a target group using fish length data, we intended to improve the length frequency analysis (LFA), which Schnute and Fournier had introduced in 1980. Our study was different in two ways from the Schnute and Fournier's method. First we calculated not only point estimates of age compositions but also the uncertainty in those estimates. Second, we modified LFA based on the von Bertalanffy growth model (vB-based model) to allow both individual-to-individual and cohort-to-cohort variability in estimates of parameters in the vB-based model. For illustration, we used data about lengths of Korean mackerel Scomber japonicas caught by purse-seine fisheries from 2000-2016.

A Critical Analysis of the Characteristics and Causes of the Changes in Marriage Rates and Recommendations for Family Policy (혼인율 특성, 변화요인 분석과 가족정책 제언)

  • Chung, Hyun-Sook
    • Journal of Families and Better Life
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    • v.24 no.6 s.84
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    • pp.177-193
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    • 2006
  • This study analyzes marriage and fertility rates in Korea and makes recommendations for family policy. Based on the 'The Report of Marriage & Divorce Statistics in 2005' and data from the Korea Statistical Information System (KOSIS) of the National Statistics Organization, the trends, reasons for marriage rates changes, and future expectations were critically reviewed. In addition, the relationship between marriage and fertility rates was analyzed. The principle characteristics of marriage rates are as follows: 1) the M-shape of the longitudinal crude marriage rates; 2) the increased age of individuals entering their the first marriage; 3) the increase in remarriage rates; 4) the changes in the patterns of remarriage; 5) the increased in the age at which individuals remarry and; 6) the increase in marriage to non-Koreans. The marriage and fertility rates changes are a permanent normative shift because of 1) later marriage because of women's increased education and labor force participation 2) rational choices about birth control 3) reduced population because of the aging of baby boomers 4) structural changes in the marriage market and 5) egalitarian changes in women's attitudes toward marriage and family. The recommendations for future family policy were as follows: 1) the need for a realistic, long-term family policy because the current marriage patterns will continue; 2) the need to develop new statistics such as fertility rates that are based on marriage cohort or birth cohort because family behavior is a mixture of personal, social and political responses; 3) the need for impact analysis of current family policy about increasing fertility rates; 4) the need for a new family perspective that encompasses diverse marriage and family patterns; 5) the need to focus on men's role in families because of women's changing roles and family interaction patterns and; 6) the need for preventive family policies such as family life education.

Metabolic Syndrome and Sasang Constitution in Cohort Study (사상체질과 대사증후군 유발에 관한 코호트 연구)

  • Yun, Woo-Yeong;Yu, Jun-Sang;Park, Jong-Ku
    • Journal of Sasang Constitutional Medicine
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    • v.25 no.1
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    • pp.1-13
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    • 2013
  • Objectives This study is to investigate the related factors to contribute the metabolic syndrome according to Sasang Constitution. Methods Nine hundred twenty six persons out of 1774 persons, over 40 years old, participated in community-based cohort in Wonju City of South Korea from June 2006 to August 2009. The diagnosis of metabolic syndrome was carried out by NCEP-ATP III(National Cholesterol Education Program in Adult Treatment Panel III) and Asian Pacific Criteria for abdominal obesity. The related factors were checked using questionnaire and blood samples. Sasang Constitution was verified by a Sasang Constitution specialist using the results of PSSC(Phonetic System for Sasang Constitution), facial pictures and simplified Sasang Constitutional questionnaires. Metabolic syndrome incidence rate according to Sasang Constitution and binary logistic regression analysis were performed with SPSS 19.0. Results Metabolic syndrome incidence rate was 30.3% and the majority of newly categorized as metabolic syndrome was Taeeumin(40.7%). There were significant risk factors like systolic blood pressure, fasting blood sugar, triglyceride and female and a significant defense factor like HDL-cholesterol. In terms of constitutional view, there were significant risk factors like waist circumference, systolic blood pressure, triglyceride in Soyangin, female, waist circumference, systolic blood pressure, fasting blood sugar, triglyceride in Taeeumin, female, waist circumference, systolic blood pressure, triglyceride in Soeumin. And there was a significant defense factor like HDL-cholesterol in only Taeeumin. Conclusions Regimens on metabolic syndrome were considered to be changed according to Sasang Constitution. Taeeumin female and Soeumin female should be cautious of body weight and metabolic syndrome when elderly. There are more cautious risk factors in each constitution; systolic blood pressure and triglyceride in Soyangin and fasting blood sugar and serum lipids levels in Soeumin and Taeeumin.

Novel Genetic Associations Between Lung Cancer and Indoor Radon Exposure

  • Choi, Jung Ran;Koh, Sang-Baek;Park, Seong Yong;Kim, Hye Run;Lee, Hyojin;Kang, Dae Ryong
    • Journal of Cancer Prevention
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    • v.22 no.4
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    • pp.234-240
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    • 2017
  • Background: Lung cancer is the leading cause of cancer-related death worldwide, for which smoking is considered as the primary risk factor. The present study was conducted to determine whether genetic alterations induced by radon exposure are associated with the susceptible risk of lung cancer in never smokers. Methods: To accurately identify mutations within individual tumors, next generation sequencing was conduct for 19 pairs of lung cancer tissue. The associations of germline and somatic variations with radon exposure were visualized using OncoPrint and heatmap graphs. Bioinformatic analysis was performed using various tools. Results: Alterations in several genes were implicated in lung cancer resulting from exposure to radon indoors, namely those in epidermal growth factor receptor (EGFR), tumor protein p53 (TP53), NK2 homeobox 1 (NKX2.1), phosphatase and tensin homolog (PTEN), chromodomain helicase DNA binding protein 7 (CHD7), discoidin domain receptor tyrosine kinase 2 (DDR2), lysine methyltransferase 2C (MLL3), chromodomain helicase DNA binding protein 5 (CHD5), FAT atypical cadherin 1 (FAT1), and dual specificity phosphatase 27 (putative) (DUSP27). Conclusions: While these genes might regulate the carcinogenic pathways of radioactivity, further analysis is needed to determine whether the genes are indeed completely responsible for causing lung cancer in never smokers exposed to residential radon.

Study on the prevalence and incidence of urolithiasis in Korea over the last 10 years: An analysis of National Health Insurance Data

  • Jung, Joon Se;Han, Chang Hee;Bae, Sangrak
    • Investigative and Clinical Urology
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    • v.59 no.6
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    • pp.383-391
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    • 2018
  • Purpose: We aimed to analyze the incidence and prevalence of urolithiasis in Korea over the last decade using the National Health Insurance (NHI) sample cohort data. Materials and Methods: From January 2002 to December 2013, we enrolled sample cohort data from the NHI. Patients diagnosed with international classification of diseases code N20 or N13.2 were included. The incidence and prevalence rate was counted from the same period and patients previously diagnosed with urolithiasis were excluded. We compared the incidence and prevalence of urolithiasis by region, age, and sex, and identified the changes. Results: Total 1,111,828 subjects were included. Of these subjects, 36,857 had urolithiasis. The male-to-female ratio was 1.57:1, and total incidence rate was 3.27 per 1,000 person-years (1,000p-yrs). The annual incidence was lowest in 2013 (3,138 patients) and highest in 2005 (3,751 patients). Incidence rate by diagnostic code was highest in ureter stone only (2.49 per 1,000p-yrs) and was lowest in kidney and ureter stone both (0.17 per 1,000p-yrs). Prevalence gradually increased from 3,172 in 2002 and 5,758 in 2013. Jeollanam-do had the highest incidence rate of 3.70 persons per 1,000p-yrs, and Jeju had the lowest rate of 2.84 persons per 1,000p-yrs. In gender analysis, Daegu had the highest incidence (4.56) in males, Jeollanam-do had the highest incidence (3.20) in females. Conclusions: Annual incidence remained stable, whereas prevalence gradually increased. The incidence in male was 1.57 times higher than female, and the peak incidence age was 45-49 years, with the highest incidence occurring in Jeollanam-do and the lowest in Jeju.

Ownership of Long-Term Care Facility and Incidence of Pressure Ulcers among Republic of Korea

  • Chun, Sung-Youn;Park, Hyeki;Kim, Woorim;Joo, Yeong-Jun;Lee, Tae-Hoon;Park, Eun-Cheol
    • Health Policy and Management
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    • v.30 no.4
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    • pp.522-530
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    • 2020
  • Background: In 2008, Korea implemented a new type of social insurance known as "long-term care insurance". We examined the association between ownership of long-term care facilities and the incidence of pressure ulcers after the implementation of "long-term care insurance". This study is a population-based retrospective cohort study from 2006 to 2013. Methods: We used medical claims data from the Korean National Health Insurance Corporate Elderly Cohort Database from 2006 to 2013. These data comprise a nationally representative sample. To avoid confounders, only patients admitted to one long-term care facility and who stayed for >70% of the follow-up time were included; as a result, 3,107 individuals were enrolled. The main independent variable was the operating entity of the long-term care facility (local government, corporate bodies, and private for-profit owners), and the dependent variable was the 1-year incidence of pressure-ulcers. Survival analysis (Cox proportional hazard model) was used as an analysis method. Results: Compared to patients admitted to local government long-term care facilities, patients admitted to private long-term care facilities had a significantly higher 1-year risk of pressure ulcers (hazard ratio [HR], 1.94; 95% confidence interval [CI], 1.29-2.91); the risk was especially high among patients who were cognitively dependent (HR, 2.34; 95% CI, 1.25-4.37). Conclusion: Patients admitted to private for-profit long-term care facilities were more likely to have pressure ulcers compared to those in local government and corporate body long-term care facilities. Appropriate assessment tools and publicly available information, as well as more restricted legal requirements, are needed to improve the care quality and outcomes of patients in long-term care facilities.

Association between breastfeeding and breast, thyroid, and cervical cancer among Korean adult women based on the Korean Genome and Epidemiology Study: a cohort study

  • Jin, Eunju;Kang, Hyunju;Son, Mia
    • Women's Health Nursing
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    • v.27 no.4
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    • pp.368-378
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    • 2021
  • Purpose: The purpose of this study was to explore the association between breastfeeding and the prevalence of breast, thyroid, and cervical cancer among Korean adult women. Methods: The study was a secondary analysis of data from the Korea Genome and Epidemiology Study. The final samples were 113,944 Korean women among 173,205 urban-based cohort participants collected between 2004 and 2013 for adults aged forty and over. To determine the association between female cancers and breastfeeding experience, the number of childbirth, and total breastfeeding duration, logistic regression analysis was done. The demographic characteristics, health behavior, and female history were adjusted. Results: The prevalence of breast cancer was 1.37 times higher in the non-breastfeeding group than in the breastfeeding group. Compared to having breastfed for more than 36 months, the prevalence of thyroid cancer was 1.68 times higher at breastfeeding for 13 to 36 months, 1.67 times higher at breastfeeding for 6 to 12 months, and 2.06 times higher at breastfeeding less than 6 months. Also, the prevalence of cervical cancer was 1.54 times higher at breastfeeding for 13 to 36 months, compared to breastfeeding for more than 36 months. Conclusion: The study found that breastfeeding experience and a longer breastfeeding duration are associated with reduced risk of breast, thyroid, and cervical cancer in Korean women. It can be used as a basis for encouraging breastfeeding, and suggests further research on modifiable factors that reduce cancer risks.

Vitamin D Deficiency and Comorbidities as Risk Factors of COVID-19 Infection: A Systematic Review and Meta-analysis

  • Mishra, Pinki;Parveen, Rizwana;Bajpai, Ram;Agarwal, Nidhi
    • Journal of Preventive Medicine and Public Health
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    • v.55 no.4
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    • pp.321-333
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    • 2022
  • Objectives: Extensive evidence links low vitamin D status and comorbidities with coronavirus disease 2019 (COVID-19) outcomes, but the results of published studies are contradictory. Therefore, we investigated the association of lower levels of vitamin D and comorbidities with the risk of COVID-19 infection. Methods: We searched MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for articles published until August 20, 2021. Sixteen eligible studies were identified (386 631 patients, of whom 181 114 were male). We included observational cohort and case-control studies that evaluated serum levels of vitamin D in COVID-19-positive and COVID-19-negative patients. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated. Results: Significantly lower vitamin D levels were found in COVID-19-positive patients (MD, -1.70; 95% CI, -2.74 to -0.66; p=0.001), but with variation by study design (case-control: -4.04; 95% CI, -5.98 to -2.10; p<0.001; cohort: -0.39; 95% CI, -1.62 to 0.84; p=0.538). This relationship was more prominent in female patients (MD, -2.18; 95% CI, -4.08 to -0.28; p=0.024) than in male patients (MD, -1.74; 95% CI, -3.79 to 0.31; p=0.096). Male patients showed higher odds of having low vitamin D levels (odds ratio [OR], 2.09; 95% CI, 1.38 to 3.17; p<0.001) than female patients (OR, 1.17; 95% CI, 0.74 to 1.86; p=0.477). Comorbidities showed inconsistent, but generally nonsignificant, associations with COVID-19 infection. Conclusions: Low serum vitamin-D levels were significantly associated with the risk of COVID-19 infection. This relationship was stronger in female than in male COVID-19 patients. Limited evidence was found for the relationships between comorbidities and COVID-19 infection, warranting large population-based studies to clarify these associations.

The Impact of a Traditional Culture Seminar on the Output of College Students' Chinese Creative Writing

  • Hou, Nai-ming;Cui, Xiang-zhe
    • International journal of advanced smart convergence
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    • v.11 no.4
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    • pp.206-215
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    • 2022
  • For a long time, traditional culture has been regarded as one of the sources of the inspiration, method and language of Chinese writing. In this article, we studied the medium- and long-term impact of a traditional Chinese culture seminar attended by college students on the output of creative writing. The seminar included traditional Chinese philosophy, history, literature, art, etc. It spanned three years (22 months) and held lectures lasting for approximately two hours once a week. The subjects of the prospective cohort study included 130 first-year college students who participated in the seminar and 130 controls. From September 2016 to June 2018, 72 lectures were held. We measured the creative writing output from the first lecture (September 2016) to December 2021 (64 months in total), including novels, essays, poems, and plays. Two indicators, the total number of words (TNW) and the quality of yield (QY), were evaluated by a 15-member panel. Although the TNW and QY of the participants and their controls were similar before the seminar, we found that the participants have higher TNW and QY than the controls after participating in the seminar. The difference in TNW became significant after month 51 (p<0.05), and the difference in QY became significant after month 46 (p<0.05). After these dates, the differences stabilized. In addition, text analysis indicates that by month 64, traditional cultural elements in the works of the participating group had a higher frequency (p<0.001). The research shows that the traditional culture seminar not only enhanced the yield of college students' creative writing but also improved the quality of their work. The traditional cultural elements enriched the works of the seminar participants.

Risks for Readmission Among Older Patients With Chronic Obstructive Pulmonary Disease: An Analysis Using Korean National Health Insurance Service - Senior Cohort Data

  • Yu Seong Hwang;Heui Sug Jo
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.6
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    • pp.563-572
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    • 2023
  • Objectives: The high readmission rate of patients with chronic obstructive pulmonary disease (COPD) has led to the worldwide establishment of proactive measures for identifying and mitigating readmissions. This study aimed to identify factors associated with readmission, as well as groups particularly vulnerable to readmission that require transitional care services. Methods: To apply transitional care services that are compatible with Korea's circumstances, targeted groups that are particularly vulnerable to readmission should be identified. Therefore, using the National Health Insurance Service's Senior Cohort database, we analyzed data from 4874 patients who were first hospitalized with COPD from 2009 to 2019 to define and analyze readmissions within 30 days after discharge. Logistic regression analysis was performed to determine factors correlated with readmission within 30 days. Results: The likelihood of readmission was associated with older age (for individuals in their 80s vs. those in their 50s: odds ratio [OR], 1.59; 95% confidence interval [CI], 1.19 to 2.12), medical insurance type (for workplace subscribers vs. local subscribers: OR, 0.84; 95% CI, 0.72 to 0.99), type of hospital (those with 300 beds or more vs. fewer beds: OR, 0.77; 95% CI, 0.66 to 0.90), and healthcare organization location (provincial areas vs. the capital area: OR, 1.66; 95% CI, 1.14 to 2.41). Conclusions: Older patients, patients holding a local subscriber insurance qualification, individuals admitted to hospitals with fewer than 300 beds, and those admitted to provincial hospitals are suggested to be higher-priority for transitional care services.