• Safety and Health at Work
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• v.11 no.2
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• pp.173-177
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• 2020

Background: Indoor air dampness microbiota (DM) is a big health hazard. Sufficient evidence exists that exposure to DM causes new asthma or exacerbation, dyspnea, infections of upper airways and allergic alveolitis. Less convincing evidence has yet been published for extrapulmonary manifestations of dampness and mold hypersensitivity syndrome). Methods: We investigated the prevalence of extrapulmonary in addition to respiratory symptoms with a questionnaire in a cohort of nurses and midwives (n = 90) exposed to DM in a Helsinki Obstetric Hospital. The corresponding prevalence was compared with an unexposed cohort (n = 45). Particular interest was put on neurological symptoms and multiple chemical sensitivity. Results: The results show that respiratory symptoms were more common among participants of the study vs. control cohort, that is, 80 vs 29%, respectively (risk ratio [RR]: 2.56, p < 0.001). Symptoms of the central or peripheral nervous system were also more common in study vs. control cohort: 81 vs 11% (RR: 6.63, p < 0.001). Fatigue was reported in 77 vs. 24%, (RR: 3.05, p < 0.001) and multiple chemical sensitivity in 40 vs. 9%, (RR: 3.44, p = 0.01), the so-called "brain fog", was prevalent in 62 vs 11% (RR: 4.94, p < 0.001), arrhythmias were reported in 57 vs. 2.4% (RR: 19.75, p < 0.001) and musculoskeletal pain in 51 vs 22% (RR: 2.02, p = 0.02) among participants of the study vs. control cohort, respectively. Conclusion: The results indicate that the exposure to DM is associated with a plethora of extrapulmonary symptoms. Presented data corroborate our recent reports on the health effects of moist and mold exposure in a workplace.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4667-4669
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• 2013

We evaluated cigarette smoking as a risk factor for prostate cancer in a prospective, population-based cohort study. The subjects were 14,450 males among the participants in the Seoul Male Cancer Cohort Study who had at least 1-year follow-up. They were followed up between 1993 and 2008. During the 16-year follow-up period, 87 cases of prostate cancer occurred over the 207,326 person-years of the study. The age-adjusted relative risks of past and current smokers at entry were 0.60 (95%CI: 0.34-1.06) and 0.70 (95%CI: 0.43-1.13), respectively, suggesting that cigarette smoking may not be a risk factor for prostate cancer. The relationship between prostate cancer and other modifiable factors, such as Westernized diet, should be studied with the goal of establishing prevention programs for prostate cancer.

• Biomedical Science Letters
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• v.27 no.3
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• pp.187-194
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• 2021

Platelets are derived from fragments formed in the cytoplasm of bone marrow megakaryocytes. Platelet count (PLT) can be altered by factors such as platelet production, destruction, and inflammation. In a previous study, the significant single nucleotide polymorphisms (SNP) were reported by the genome-wide association study (GWAS) for PLT in Koreans. In this study, it was confirmed whether significant SNPs were replicated in the HEXA (The Health Examinees) cohort. As a result, the SNPs of the THPO (rs6141), BAK1 (rs210314, rs9296095), GGNBP1 (rs75080135), ACAD10 (rs6490294), and ABCC4 (rs4148441) were significantly correlated with PLT (P < 10^-8). At the same time, it was confirmed that the direction of influence was the same according to the genotype. In conclusion, it can be seen that common SNPs are associated with the platelet count regardless of the cohort for Koreans.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1023-1029
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• 2014

Background: The purpose of our study was to elucidate the joint effects of combined smoking and alcohol intake on esophageal cancer mortality in Japanese men through a large cohort study with a 20-year follow-up period. Materials and Methods: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study) was established in the late 1980s, including 46,395 men and 64,190 women aged 40 years and older and younger than 80. Follow-up of these participants was conducted until 2009. We used the Cox proportional hazards model to analyze data for 42,408 people excluding female participants, 411 people with histories of malignant neoplasms, and 3,576 with unclear smoking and drinking data. Results: The joint effects of age at start of smoking and amount of alcohol consumed per day were compared with non-smokers and non-drinkers or those consuming less than one unit of alcohol per day. The mortality risk was 9.33 (95% confidence interval, 2.55-34.2) for those who started smoking between ages 10 and 19 years and drinking at least three units of alcohol per day. Regarding the joint effects of cumulative amount of smoking and alcohol intake, the risk was high when both smoking and alcohol intake were above a certain level. Conclusions: In this Japanese cohort study, increased cancer mortality risks were observed, especially for people who both started smoking early and drank alcohol. Quitting smoking or not starting to smoke at any age and reducing alcohol consumption are important for preventing esophageal cancer in Japan.

• Journal of Environmental Science International
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• v.17 no.5
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• pp.517-524
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• 2008

The purpose of this study was to investigate the characteristics of air quality using data from which obtain local air quality monitoring system for cohort study in Chungju, Korea. We analyzed the concentration data of $NO_2,\;SO_2$, and $PM_{10}$ in Chungju and industrial cities in 2006. We compared a industrial area with a cohort study area using by bicluster algorithm. In the case of $SO_2$, the rate of the cluster time was $10{\sim}60%$ and the cluster time number of two areas was similar. In the case of $NO_2$ and $PM_{10}$, the number of cluster time between a industrial area and cohort study area was clearly different.

• Safety and Health at Work
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• v.8 no.2
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• pp.169-174
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• 2017

Background: We assessed the cancer risks of four different Finnish asbestos-exposed cohorts. We also explored if the cohorts with varying profiles of asbestos exposure exhibited varying relative risks of cancer. Methods: The incident cancer cases for the asbestos-exposed worker cohorts were updated to the end of 2012 using the files of the Finnish Cancer Registry. The previously formed cohorts consisted of asbestos mine workers, asbestosis patients, asbestos sprayers, and workers who had taken part in a screening study based on asbestos exposure at work. Results: The standardized incidence ratio (SIR) for mesothelioma varied from about threefold to > 100-fold in the different cohorts. In the screening cohort the SIR for mesothelioma was highest in 2003-2007, In other cohorts it was more constant in 5-year period inspection. The SIR for lung cancer was about twofold to tenfold in all except the screening cohort. Asbestos sprayers were at the highest risk of mesothelioma and lung cancer. Conclusion: The SIR for mesothelioma is high in all of the cohorts that represent different kinds of asbestos exposure. The smaller SIR for mesothelioma in the screening cohort with lowest level of asbestos exposure might suggest dose-responsiveness between asbestos exposure and mesothelioma. It does seem that the highest risk of lung cancer in these cohorts except in the youngest of the cohorts, the screening cohort, is over. The highest SIR for lung cancer of the asbestosis patient and sprayers cohort is explained by their heavy asbestos exposure.

• Journal of Preventive Medicine and Public Health
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• v.53 no.5
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• pp.313-322
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• 2020

Objectives: This study was conducted to determine the incidence and risk factors of myocardial infarction (MI) and stroke in farmers compared to the general population and to establish 5-year prediction models. Methods: The farmer cohort and the control cohort were generated using the customized database of the National Health Insurance Service of Korea database and the National Sample Cohort, respectively. The participants were followed from the day of the index general health examination until the events of MI, stroke, or death (up to 5 years). Results: In total, 734 744 participants from the farmer cohort and 238 311 from the control cohort aged between 40 and 70 were included. The age-adjusted incidence of MI was 0.766 and 0.585 per 1000 person-years in the farmer and control cohorts, respectively. That of stroke was 0.559 and 0.321 per 1000 person-years in both cohorts, respectively. In farmers, the risk factors for MI included male sex, age, personal history of hypertension, diabetes, current smoking, creatinine, metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). Those for stroke included male sex, age, personal history of hypertension, diabetes, current smoking, high γ-glutamyl transferase, and metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). The prediction model showed an area under the receiver operating characteristic curve of 0.735 and 0.760 for MI and stroke, respectively, in the farmer cohort. Conclusions: Farmers had a higher age-adjusted incidence of MI and stroke. They also showed distinct patterns in cardiovascular risk factors compared to the general population.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.23.1-23.6
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• 2016

Objectives A stable follow-up participation rate is a very important factor for validity in a cohort study. This study analyzed the factors that affect the participation rate at one hospital-based birth cohort in South Korean. Methods The participants were recruited from the Mothers' and Children's Environmental Health study between 2006 and 2010. The analysis targeted 1751 mothers who participated in a birth cohort. We conducted analyses of general characteristics during pregnancy and those of infants at birth that affect the participation rate of the 6-month follow-up survey. Results The participation rate for the 6-month follow-up survey was 60.4%. The participation rate in the follow-up of the subsequent period decreased within a 5% to 10% range compared to the number of subjects. The participation rate of premature infants was 16.9% lower than that of a full-term infant (52.6% vs. 69.5%). Analysis showed a 16.7% difference between the participation rate of low-birthweight infants in follow-ups (53.7%) and the participation rate of infants with normal weight (70.4%). The participation rate of mothers who were employed during pregnancy was significantly lower for the 6-month follow-up compared to the participation rate of mothers who were unemployed during pregnancy. Conclusions In this study, factors such as premature birth, low-birthweight, and the employment status of the mother during pregnancy affected the participation rate of the follow-up survey for the birth cohort at six months. A specific strategy is needed to encourage survey participation for the high risk groups in the follow-ups.

• Journal of Preventive Medicine and Public Health
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• v.55 no.4
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• pp.313-320
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• 2022

The KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) was launched in 2011 with the support of the Korea Disease Control and Prevention Agency. The study was designed with the aim of exploring the various clinical features and characteristics of chronic kidney disease (CKD) in Koreans, and elucidating the risk factors for CKD progression and adverse outcomes of CKD. For the cohort study, nephrologists at 9 tertiary university-affiliated hospitals participated in patient recruitment and follow-up. Biostatisticians and epidemiologists also participated in the basic design and structuring of the study. From 2011 until 2016, the KNOW-CKD Phase I recruited 2238 adult patients with CKD from stages G1 to G5, who were not receiving renal replacement therapy. The KNOW-CKD Phase II recruitment was started in 2019, with an enrollment target of 1500 subjects, focused on diabetic nephropathy and hypertensive kidney diseases in patients with reduced kidney function who are presumed to be at a higher risk of adverse outcomes. As of 2021, the KNOW-CKD investigators have published articles in the fields of socioeconomics, quality of life, nutrition, physical activity, renal progression, cardiovascular disease and outcomes, anemia, mineral bone disease, serum and urine biomarkers, and international and inter-ethnic comparisons. The KNOW-CKD researchers will elaborate a prediction model for various outcomes of CKD such as the development of end-stage kidney disease, major adverse cardiovascular events, and death.

• Korean Medical Education Review
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• v.24 no.3
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• pp.250-260
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• 2022

Evaluating the effectiveness of educational programs involves measuring learning processes as well as outcomes. It is essential to study cohorts of students and graduates to evaluate the long-term effects of educational programs with data generated both during education and after graduation. The purpose of this study was to establish cohorts of students and graduates to evaluate their performance, thereby providing a basis for evaluating the social accountability of medical education. In this study, student and graduate cohorts were built for both students currently enrolled and graduates at Inje University College of Medicine (IUCM). A model involving the process of cohort establishment and an evaluation indicator framework was developed. In the process of cohort establishment, the following steps were conducted: defining the goals and objectives of the student and graduate cohorts, organizing a cohort committee, developing regulations, registering cohorts, acquiring consent, and building a database. A framework of evaluation indicators according to the graduate roles of IUCM was developed by adapting Kirkpatrick's evaluation model. Next, items to be collected in student and graduate cohorts were selected, and the current status of existing data was analyzed. Moreover, a preliminary analysis was conducted, including analyses of the evaluation indicators and graduates' performance. This study suggests that it is necessary to include additional evaluation indicators considering students' learning environment and well-being in student cohorts and to develop strategies or methods for graduates to continue participating in data collection for a long-term study.