• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.347-373
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• 2021

Over the past 50 years, explorative research on the nation's mortality decline patterns has showed a decrease in age-specific mortality rates in all age groups, but there were different improvement patterns in specific mortality rates depending on ages and periods. Greater distinct improvement was observed in mortality rates among women than men, and there was a noticeable improvement in mortality rates in certain groups especially in the more recent decades, revealing a structural change in the overall trends regarding death periods. In this paper, we compare various stochastic mortality models considering cohort effects for mortality projection using Korean female mortality data and further explore the uncertainty related to projection. It also created age-specific mortality rates and life expectancy for women until 2067 based on the results of the analysis, and compared them with future age-specific mortality rates and life expectancy provided by the national statistical office (KOISIS). The best optimal model could vary depending on data usage periods. however, considering the overall fit and predictability, the PLAT model would be regarded to have appropriate predictability in terms of the mortality rates of women in South Korea.

• Journal of Society of Preventive Korean Medicine
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• v.25 no.3
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• pp.25-37
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• 2021

Objectives : To investigate the effectiveness of Korean Medicine services use on the all-cause mortality and incidence of Parkinson's disease(PD) in elderly patients with chronic disease based on the National Health Insurance Service Corhort Database (elderly), called as the NHIS-senior. Methods : This study was a retrospective cohort analysis conducted using the NHIS-senior. Patients with chronic diseases over 65 years old who were not diagnosed PD during 2007-2009 were identified. The case group was defined as patients who used both Korean Medicine and Western Medicine services and the control group consisted of patients who used Western Medicine service only. The all-cause mortality and incidence of PD was analyzed using the Cox proportional hazard model after a propensity score matching(PSM) with a 1:1 ratio. Results : After PSM, the cohort included 47,546 subjects (23,773 in the case group, 23,773 in the control group). Sex, age, comorbidity, severity of disability, and neurology medical service utilization were adjusted in both groups. The mortality was 0.668 times (95% C.I.: 0.646-0.690) lower in the case group than the control group, which was statistically significant (p<0.001). The incidence of PD was 1.051 times (95% C.I.: 0.962-1.148) higher in the case group than the control group, which was not statistically significant(p=0.272). Conclusion : It was not obvious that the use of both Korean Medicine service and Western Medicine services for prevention of PD is benefitial than using only Western Medicine. But it would be possible that using both Korean Medicine and Western Medicine services decreases the mortality than using Western Medicine alone.

• Korean Medical Education Review
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• v.24 no.2
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• pp.156-171
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• 2022

The purpose of this study was to establish a model for constructing longitudinal data for medical school, and to structure cohort and longitudinal data using data from Yonsei University College of Medicine (YUCM) according to the established input-environment-output (I-E-O) model. The study was conducted according to the following procedure. First, the data that YUCM has collected was reviewed through data analysis and interviews with the person in charge of each questionnaire. Second, the opinions of experts on the validity of the I-E-O model were collected through the first expert consultation, and as a result, a model was established for each stage of medical education based on the I-E-O model. Finally, in order to further materialize and refine the previously established model for each stage of medical education, secondary expert consultation was conducted. As a result, the survey areas and time period for collecting longitudinal data were organized according to the model for each stage of medical education, and an example of the YUCM cohort constructed according to the established model for each stage of medical education was presented. The results derived from this study constitute a basic step toward building data from universities in longitudinal form, and if longitudinal data are actually constructed through this method, they could be used as an important basis for determining major policies or reorganizing the curricula of universities. These research results have implications in terms of the management and utilization of existing survey data, the composition of cohorts, and longitudinal studies for many medical schools that are conducting surveys in various areas targeting students, such as lecture evaluation and satisfaction surveys.

• Journal of Sasang Constitutional Medicine
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• v.34 no.1
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• pp.46-57
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• 2022

Background Adherence to healthy diet acts as a key role to modify sedentary lifestyle in real life setting. Constitution type of traditional Korean medicine has been prediagnosed to risk factors of cardiometabolic diseases. This study aims to evaluate the associations between body composition and healthy eating status in Korean adults by their constitution type. Methods Of 4046 participants from Korean Medicine Daejeon Citizen Cohort study, Korean Medicine Daejeon Citizen Cohort (KDCC) study were included for analysis. Demographic, health-related behaviors and Korean Medicine (KM) type were surveyed based on a general health-related questionnaire. Anthropometric measurements and dietary factors by using Korean Healthy Eating Index (KHEI) were assessed only in the half of the original participants. Results 50.8% of Taeeum was observed from eligible 1967 participants (66.7%, women). The highest KHEI score was observed in soyang group (52.0±0.3, p=0.006) compared to other two groups. In taeeum group, lower appendicular skeletal muscle mass (ASM)(%)(Taeeum: 38.7±0.1 vs. Soeum/Soyang: 39.2±0.1, p < 0.05), and higher percent of body fat (PBF)(%) (Taeeum: 32.9±0.2 vs. Soeum/Soyang: 29.0±0.2, p < 0.05) by the lowest tertile (T1) of the KHEI score, respectively. When the KHEI score increased by 1 point in taeeum group, a positive relationship was observed, which increased by 0.015% of ASM, however, a negatively related to in which body fat mass (BFM) decreased by 0.022 kg and PBF decreased by 0.024%. Conclusion Customized nutritional management is required that could help maintaining physical health and diet by their constitution type.

• Journal of Korean Academy of Nursing
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• v.52 no.1
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• pp.24-35
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• 2022

Purpose: This study investigated the incidence and risk factors of cataract in people with diabetes mellitus (DM) using data from Ansan cohort of the Korean Genome and Epidemiology Study (KoGES). Methods: Data from a total of 329 patients with type 2 DM without cataract who participated in Ansan cohort of the KoGES from baseline survey (2001-2002) to fifth follow-up visit (2011-2012) were examined. The characteristics of the subjects were analyzed with frequency and percentage, and mean and standard deviation. Cataract incidence was measured as incidence proportion (%). For risk factors of cataract, hazard ratio (HR) and 95% confidence interval (CI) were obtained using the Cox proportional hazard model. Results: The cataract incidence over a 10-year follow-up period was 19.1% (15.1 in males and 25.8 in females), and mean age at the incidence of cataract was 63.48 years (61.58 years in males and 65.31 years in females). Age (HR=1.09, 95% CI=1.05-1.13) and HbA1c (HR=1.21, 95% CI=1.07-1.37) or the duration of DM (HR=1.05, 95% CI=1.00-1.09) were found to be independently associated with cataract development. Conclusion: Cataract development in people with DM is common, and its likelihood increases with age, HbA1c, and the duration of DM. Considering negative effect of cataract on their quality of life and economic burden, nurses should identify people with DM at a higher risk of cataract development, and plan individual eye examination programs to detect cataract development as early as possible.

• Korean Medical Education Review
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• v.25 no.2
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• pp.84-101
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• 2023

Longitudinal data can provide important evidence with the potential to stimulate innovation and affect policies in medical education and can serve as a driving force for further developments in medical education through evidence-based decisions. Tracking and observing cohorts of students and graduates using longitudinal data can be a way to link the past, present, and future of medical education. This study reviewed practical methods and technical, administrative, and ethical considerations for the establishment and operation of a longitudinal database and presented examples of longitudinal databases. Cohort study design methods and previous examples of research using longitudinal databases to explore major topics in medical education were also reviewed. The implications of this study are as follows: (1) a systematic design process is required to establish longitudinal data, and each university should engage in ongoing deliberation about this issue; (2) efforts are needed to alleviate "survey fatigue" among respondents and reduce the administrative burden of those conducting data collection and analysis; (3) it is necessary to regularly review issues of personal information protection, data security, and ethics regarding the survey respondents; and (4) a system should be established that integrates and manages a longitudinal database of medical education at the national level. The hope is that establishing longitudinal data and cohorts at individual medical schools will not be a temporary phenomenon, but rather that they will be well utilized at the national level to innovate and implement ongoing changes in medical education.

• Safety and Health at Work
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• v.14 no.3
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• pp.279-286
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• 2023

Background: This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. Methods: This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012-2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. Results: The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36-1.54) and workers who were exposed to noise (1.15:1.07-1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. Conclusions: Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.

• Journal of Rhinology
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• v.59 no.3
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• pp.292-300
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• 2021

Background: Chronic rhinosinusitis (CRS) and chronic otitis media (COM) share pathophysiological mechanisms such as bacterial infection, biofilm, and persistence of the obstruction state of ventilation routes. However, only a few studies have investigated the relationship between these two diseases nationwide and in the general population. The purpose of this study was to determine whether the incidence of COM in patients with CRS differed from that of a matched control from the national health screening cohort. Methods: Data from the Korean Health Insurance Review and Assessment Service-National Patient Samples were collected from 2002 to 2015. Participants who were treated ≥2 times and underwent head and neck computed tomography evaluation were selected. A 1:4 matched CRS group (n=8,057) and a control group (n=32,228) were selected. The control group included participants who were never treated with the ICD-10 code J32 from 2002 to 2015. The CRS group included CRS patients with/without nasal polyps. Results: The incidence of COM was significantly higher in the CRS group than in the control group. In a subgroup analysis, the incidence of COM in all age groups and in men and women was significantly higher in the CRS group than in the control group. More, CRS increased the risk of COM. Conclusions: A significant association was observed between CRS and COM. This indicates that CRS patients have a high risk of developing COM.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1649-1654
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• 2014

Background: Clinically significant portal hypertension (PHT) is considered as a contraindication for hepatectomy according to the guidelines of the European Association for Study of Liver and the American Association for Study of Liver Diseases. However, this issue remains controversial. Here we performed a metaanalysis to evaluate the impact of PHT on the results of hepatectomy for hepatocellular carcinoma (HCC). Methods: Cohort studies evaluating the impact of clinically significant PHT, defined as oesophageal varices and/or splenomegaly associated with thrombocytopenia, on the results of hepatectomy for HCC were identified using a predefined search strategy. Summary risk ratios (RRs) and 95% confidence intervals (95% CIs) for PHT and outcomes after hepatectomy for HCC were calculated. Results: Seven cohort studies which including 574 cases with PHT and 1,354 cases without PHT were considered eligible for inclusion. The meta-analysis showed that, in all patients, pooled RRs of post-operative liver failure, post-operative ascites, peri-operative blood transfusion, operative mortality, 3- and 5-year overall survival associated with PHT were 2.23 (95% CI: 1.48-3.34, P=0.0001), 1.77 (95% CI: 1.19-2.64, P=0.005), 1.23 (95% CI: 1.03-1.49, P=0.03), 2.58 (95% CI: 1.12-5.96, P=0.03), 0.82 (95% CI: 0.75-0.88, P<0.00001) and 0.76 (95% CI: 0.69-0.85, P<0.00001), respectively. In subgroup analysis, similar results were found in Child-Pugh class A patients. Conclusion: This meta-analysis suggests that presence of oesophageal varices and/or splenomegaly associated with thrombocytopenia is associated with higher rates of post-operative complications and poor long-term survival after hepatectomy for HCC.

• Tuberculosis and Respiratory Diseases
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• v.85 no.4
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• pp.349-357
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• 2022

Background: The most consistently identified mortality determinants for the new coronavirus 2019 (COVID-19) infection are aging, male sex, cardiovascular/respiratory diseases, and cancer. They were determined from heterogeneous cohorts that included patients with different disease severity and previous conditions. The main goal of this study was to determine if activities of daily living (ADL) dependence measured by Barthel's index could be a predictor for COVID-19 mortality. Methods: A prospective cohort study was performed with a consecutive sample of 340 COVID-19 patients representing patients from all over the northern region of Portugal from October 2020 to March 2021. Mortality risk factors were determined after controlling for demographics, ADL dependence, admission time, comorbidities, clinical manifestations, and delay-time for diagnosis. Central tendency measures were used to analyze continuous variables and absolute numbers (proportions) for categorical variables. For univariable analysis, we used t test, chi-square test, or Fisher exact test as appropriate (α=0.05). Multivariable analysis was performed using logistic regression. IBM SPSS version 27 statistical software was used for data analysis. Results: The cohort included 340 patients (55.3% females) with a mean age of 80.6±11.0 years. The mortality rate was 19.7%. Univariate analysis revealed that aging, ADL dependence, pneumonia, and dementia were associated with mortality and that dyslipidemia and obesity were associated with survival. In multivariable analysis, dyslipidemia (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.17-0.71) was independently associated with survival. Age ≥86 years (pooled OR, 2.239; 95% CI, 1.100-4.559), pneumonia (pooled OR, 3.00; 95% CI, 1.362-6.606), and ADL dependence (pooled OR, 6.296; 95% CI, 1.795-22.088) were significantly related to mortality (receiver operating characteristic area under the curve, 82.1%; p<0.001). Conclusion: ADL dependence, aging, and pneumonia are three main predictors for COVID-19 mortality in an elderly population.