• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.3
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• pp.268-278
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• 2022

Objectives: This study aimed to establish a control group based on the big data from National Health Insurance Service. We also presented presented the number of incidences for each cancer, and analyzed the cancer incidence rate among Korean workers. Methods: The cohort definition was separated by 'baseline cohort', 'dynamic cohort', and 'fixed- industry cohort' according to the definition. Cancer incidence was calculated based on the Korean Standard Classification of Disease code. Incidence rate was calculated among the group of all workers and public officials. Based on the study subjects and each cohort definition, the number of observations, incidences, and the incidence rate according to sex and age groups was calculated. The incidence rate was estimated based on the incidence per 100,000 person-year, and 95% confidence intervals calculated according to the Poisson distribution. Results: The result shows that the number of cancer cases in the all-worker group decreases after the age of 55, but the incidence rate tends to increase, which is attributed to the retirement of workers over 55 years old. Despite the specific characteristics of the workers, the trend and figures of cancer incidence revealed in this study are similar to those reported in previous studies of the overall South Korean population. When comparing the incidence rates of all workers and the control group of public officials, the incidence rate of public officials is generally observed to be higher in the age group under the age of 55. On the other hand, for workers aged 60 or older, the incidence rates were 1,065.4 per 100,000 person-year for all workers and 1,023.7 per 100,000 person-year for civil servants. Conclusions: This study analyzed through health insurance data including all workers in Korea, and analyzed the incidence of cancer of workers by sex and age. In addition, further in-depth researches are needed to determine the incidence of cancer by industry.

• The Korea Genome Conference
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• 2006.09a
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• pp.38-38
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• 2006

• 대한생식의학회:학술대회논문집
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• 2006.11a
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• pp.109-110
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• 2006

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.193-200
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• 2020

Purpose: To investigate the relationship between dementia and complete tooth loss on both sides or one side using large demographic data. Materials and methods: A retrospective cohort study was designed using the National Health Insurance Service-Elderly Cohort Database (NHIS-ECD) which was established for people over the age of 60. The experimental group was the complete edentulous cohort, which had a history of treatment for national health insurance covered complete denture on both sides or one side from July 1, 2012 to December 31, 2013. And the control group was the dentulous cohort, which had a history of conservative dental treatment for the same period. All subjects had no history of diagnosis or treatment of dementia during this time. These cohorts were matched 1:1 by age, gender, and place of residence according to the propensity score matching method. Then the incidence of dementia was compared between these cohorts. Results: Compared with those groups, the incidence of dementia was significantly higher in the experimental group (12.13%) than in the control group (9.74%) (P<.05). No clear association between other factors has been identified. Conclusion: The analysis of large-scale demographic data shows that the incidence of dementia is high in complete edentulous patients on both sides or one side.

• Integrative Medicine Research
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• v.7 no.1
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• pp.95-102
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• 2018

Background: Hypertension is a major cause of cardiovascular disease and associated mortality, and postmenopausal women are at a high risk of hypertension. We aim to investigate the hypotensive effect and safety of acupuncture, focusing on postmenopausal women with prehypertension and stage 1 hypertension. In addition, we aim to investigate whether the effect of acupuncture treatment differed, depending on Sasang Constitution and cold-heat pattern. Methods: This study is designed as an intervention cohort study. Two hundred postmenopausal women aged <65 years with prehypertension or stage 1 hypertension living in Daejeon city in Korea will be recruited, and randomly assigned to either an acupuncture or no-treatment control group. The intervention will consist of four sessions; one session will include acupuncture performed 10 times for 4 weeks. There will be a 20-week observation period after each session, and the total study duration will be 96 weeks. Acupuncture will be applied at the bilateral Fengchi (GB20), Quchi (LI11), Zusanli (ST36), and Sameumgyo (SP6) acupoints. The effect of acupuncture will be evaluated by comparing the change in systolic and diastolic blood pressure between the acupuncture and control groups every 4 weeks until the end of the study. Discussion: To evaluate the success of blood pressure management, long-term observation is required, but no long-term studies have been conducted to evaluate the effect of acupuncture on blood pressure in postmenopausal women. To our knowledge, this study will be the first long-term study to investigate this issue for more than 6-8 weeks.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.213-222
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• 2003

Genomic epidemiology is defined as 'an evoking field of inquiring that uses the systematic application of epidemiologic methods are approaches in population-based studies of the impact of human genetic variation on health and disease (Khoury, 1998)'. Most human diseases are caused by the intricate interaction among environmental exposures and genetic susceptibility factors. Susceptibility genes involved in disease pathogenesis are categorized into two groups: high penetrance genes (i.e., BRAC1, RB, etc.) and lour penetranoe genes (i.e., GSTs, Cyps, XRCC1, ets.), and low penetrance susceptibility genes has the higher priority for epidemiological research due to high population attributable risk. In this paper, the summarized results of the association study between single nucleotide polymorphisms (SNPs) and breast cancer in Korea were introduced and the international trends of genomic epidemiology research were reviewed with an emphasis on internee-based case-control and cohort consortium.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.243-248
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• 2004

The timings of two successive events of interest may not be measurable, instead it may be right censored or interval censored; this data structure is called doubly censored data. In the study of HIV, two such events are the infection with HIV and the onset of AIDS. These data have been analyzed by authors under the assumption that infection time and induction time are independent. This paper investigates the regression problem when two events arc modeled to allow the presence of a possible relation between two events as well as a subject-specific effect. We derive the estimation procedure based on Goetghebeur and Ryan's (2000) piecewise exponential model and Gauss-Hermite integration is applied in the EM algorithm. Simulation studies are performed to investigate the small-sample properties and the method is applied to a set of doubly censored data from an AIDS cohort study.

• Journal of Preventive Medicine and Public Health
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• v.38 no.4
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• pp.425-430
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• 2005

Objectives : To investigate the prevalence of Clonorchis Sinensis infestation and to determine the associated risk factors among a population in a part of the rural area of Gyeongsangnam-do, Korea, which is an area known to have a high mortality from liver cancer and a high infection of C. sinensis. Methods : The study populat ion consisted of those people who have lived in rural areas and who were over 40 years old. This study was performed in 5 areas during the period from 1999 to 200 3. Informed consents were obtained from the 2,381 study participants, and these people were interviewed about their life style habits with using the structured questionnaire that was administered by trained staff members. The subjects underwent blood sampling and their stool specimens were examined by using the Formalin-ether sedimentation technique. Results : Among the study subjects (N=2,381), the positivity for C. sinensis in the stool was 34.4% (95% CI=36.3-42.5); it was 39.4% (95% CI=36.3-42.5) in the males and 30.9% (95% CI=28.5-33.3) in the females . The positivity for C. sinensis was associated with current alcohol drinking (odds ratio=1.8, 95% CI: 1.5-2.1) and raw fish consumption (odds ratio 1.2, 95% CI: 0.9-1.6). Conclusion : The present study confirmed the high prevalence of C. sinensis in the study subjects. It is necessary to establish consistent medical management and education programs for the treatment and prevention of C. sinensis infestation in the rural inhabitants of Korea.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4713-4717
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• 2012

Objectives: This systematic review of cohort studies aimed to identify any association between specific dietary patterns and risk of colorectal cancer (CRC). Dietary patterns involve complex interactions of food and nutrients summarizing the total diet or key aspects of the diet for a population under study. Methods and materials: This review involves 6 cohort studies of dietary patterns and their association with colorectal cancer. An exploratory or a posteriori approach and a hypothesis-oriented or a priori approach were employed to identify dietary patterns. Results: The dietary pattern identified to be protective against CRC was healthy, prudent, fruits and vegetables, fat reduced/diet foods, vegetables/fish/poultry, fruit/wholegrain/dairy, healthy eating index 2005, alternate healthy eating index, Mediterranean score and recommended food score. An elevated risk of CRC was associated with Western diet, pork processed meat, potatoes, traditional meat eating, and refined grain pattern. Conclusion: The Western dietary pattern which mainly consists of red and processed meat and refined grains is associated with an elevated risk of development of CRC. Protective factors against CRC include a healthy or prudent diet, consisting of vegetables, fruits, fish and poultry.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.207-211
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• 2008

We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan, Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence, Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed, However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives, As a result, small ramets were semi-evergreen, whereas large ramets were deciduous, The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.