• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.26.1-26.15
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• 2023

Background: The objective of this study is to investigate the differences in incidence rates of targeted diseases by classification of occupations among construction workers in Korea. Methods: In a subject-based cohort of the Korean Construction Worker's Cohort, we surveyed a total of 1,027 construction workers. As occupational exposure, the classification of occupations was developed using two axes: construction business and job type. To analyze disease incidence, we linked survey data with National Health Insurance Service data. Eleven target disease categories with high prevalence or estimated work-relatedness among construction workers were evaluated in our study. The average incidence rates were calculated as cases per 1,000 person-years (PY). Results: Injury, poisoning, and certain other consequences of external causes had the highest incidence rate of 344.08 per 1,000 PY, followed by disease of the musculoskeletal system and connective tissue for 208.64 and diseases of the skin and subcutaneous tissue for 197.87 in our cohort. We especially found that chronic obstructive pulmonary disease was more common in construction painters, civil engineering welders, and civil engineering frame mold carpenters, asthma in construction painters, landscape, and construction water proofers, interstitial lung diseases in construction water proofers. Conclusions: This is the first study to systematically classify complex construction occupations in order to analyze occupational diseases in Korean construction workers. There were differences in disease incidences among construction workers based on the classification of occupations. It is necessary to develop customized occupational safety and health policies for high-risk occupations for each disease in the construction industry.

• Communications for Statistical Applications and Methods
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• 제25권5호
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• pp.545-557
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• 2018

The inclusion of covariates in the model often affects not only the estimates of meaningful variables of interest but also its statistical significance. Such gap between statistical and subject-matter significance is a critical issue in huge sample studies. A popular huge sample study, the sample cohort data from Korean National Health Insurance Service, showed such gap of significance in the inference for the effect of obesity on cause of mortality, requiring careful consideration. In this regard, this paper proposes a sample size calibration method based on a Monte Carlo t (or z)-test approach without Monte Carlo simulation, and also proposes a test procedure for subject-matter significance using this calibration method in order to complement the deflated p-value in the huge sample size. Our calibration method shows no subject-matter significance of the obesity paradox regardless of race, sex, and age groups, unlike traditional statistical suggestions based on p-values.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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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.

• 한국생활과학회지
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• 제21권4호
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• pp.629-647
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• 2012

This study explored what Korean college students, especially preservice teacher in early childhood education, experienced and how they constructed the meanings of experiences about their subject- matter course (early childhood mathematics education) taught in English. One cohort- 20 senior students- majoring in early childhood education in a 4-year university was participated in this study. Using action research method and narrative research method, data were analyzed. The findings were as follows: 1) preservice teacher experienced some difficulties to construrct professional knowledge through English. 2) They challenged to overcome these difficulties through active participation. 3) They got supports from instructor and peer group. 4) They accomplished the course with self-satisfaction. 5) They experienced the conflicts between social requirements and personal needs.

• Tuberculosis and Respiratory Diseases
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• 제63권5호
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• pp.405-411
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• 2007

연구배경: 본 연구를 통해 2005년도 ATS/ERS 폐활량검사 지침에서 제시한 재현성 기준을 한국 성인들에게 적용할 수 있는 지와, 한국 성인들의 폐활량 검사 시 재현성에 영향을 미치는 요인들을 알아보고자 하였다. 방 법: 국민건강영양조사, COPD 코호트, 지역사회 코호트로부터 얻은 성인 4,663명의 폐활량검사 결과를 이용하여 dFVC 및 $dFEV_1$를 계산하여 분포를 알아보고, 1994년도 ATS 지침 및 2005년도 ATS/ERS 지침을 만족하는 검사의 비율을 비교하였다. 다중회귀분석을 통해 개인적 특성 및 재현성 기준의 변화가 재현성에 영향을 미치는가를 알아보았다. 결 과: 폐활량검사를 시행한 사람들 중 95% 이상이 150ml 이내의 재현성 기준을 만족시켰다. 1994년도 ATS 지침에 따라 검사를 시행한 경우 재현성을 만족하지 않는 경우가 증가하였다. 다중회귀분석 결과 재현성에 영향을 주는 요인들은 신장, 연령, 체중, 폐쇄성폐질환 여부, 재현성 기준의 변화 등이었으나 재현성에 영향을 미치는 정도는 매우 작았다(0.5~3.0%). 결 론: 한국인에게도 2005년도 ATS/ERS에서 제시한 재현성 기준을 적용할 수 있을 것으로 생각하며, 이를 위해서는 변경된 재현성 기준에 대한 지속적인 홍보와 검사자 들에 대한 교육 및 정도 관리가 필요하다.

• 대한지역사회영양학회지
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• 제8권4호
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• pp.603-609
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• 2003

This study examined the reproducibility of nutrient intakes estimated by the 24-hour recall method in a prospective cohort study (Longitudinal study of aging and health monitoring of Korean elderly) of middle-aged volunteer subjects (42 males and 49 females) in the Seoul area. The three-day 24-hour recall was administered twice at an interval of approximately 6 months. The first data were collected and a corrective procedure was performed by interviewing of the subjects and a trained dietitian. The second data were collected by mail from the subjects without the performance of any corrective procedure. The mean age of the subjects was 53.5 $\pm$ 9.6 for the males and 52.2 $\pm$ 8.9 for the females. The subjects who had above college education were 95% in the case of the males and 60% in the case of the females. The characteristics of the male subjects in this study were that they were highly educated and held professional jobs and were from the middle or upper class. Comparing the first and second 24-hour recall data, the second data showed relatively lower intakes of all nutrients, except vitamin A, vitamin Bi and cholesterol. There was no difference in the nutrients of the first and the second data with respect to vitamin A, vitamin B$_1$ and cholesterol in the males and calcium, iron, sodium, vitamin A, vitamin B$_1$, vitamin B$_2$ and cholesterol in the females. This data may indicate that the 24 hour retail method without a dietitian's help may result in lower reporting of the subject's intakes. The men had a tendency to remember less than the women. Pearson's correlation coefficients with unadjusted nutrient intakes values were ranged from 0.24 to 0.66. When energy intake was adjusted, there was a slight increase (from 0.26 to 0.71). Intra-class correlation coefficients with nutrient-unadjusted values ranged from 0.22 to 0.66, and the energy-adjusted values were ranged from 0.23 to 0.69. The weighted Kappa statistical values ranged from 0.10 to 0.40. On the average,46.3% of the subjects who were found in the lowest quartile of the nutrient intake levels based on the first 24-hour recall, were in the lowest quartile based on the second 24-hour recall. Therefore, there was a low reproducibility between the first and the second 24-hour recall. We should examine the factors influencing low reproducibility. Also, strategies should be developed to maximize the reliability of the assessment, with regard to portion-size training and telephone validation. (Korean J Community Nutrition 8(4) : 603∼609, 2003)

• 한국식품영양과학회지
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• 제46권7호
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• pp.868-875
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• 2017

본 연구는 스트레스 정도에 따른 영양소 섭취와 대사증후군 위험도를 분석하고자 수행되었다. 본 연구는 40~69세 일반인구 집단을 대상으로 실시한 한국인 역학조사 사업 중 농촌 기반코호트를 이용하여 진행하였고, 그중 여성을 대상으로 분석하였다. 대상자들은 사회 심리적 건강측정도구(Psychosocial Well-being Index, PWI)를 기초로 하여 개발된 18문항의 단축형(PWI-SF)의 평균값을 기준으로 0~26점의 저스트레스군과 27점 이상인 고스트레스군으로 분류되었다. 영양 섭취 상태 및 식습관은 반정량식품섭취빈도조사방법(semi-quantitative food frequency questionnaire, SQFFQ)을 이용하여 평가하였다. 고스트레스군 대상자들은 저스트레스군보다 나이, 허리둘레, 혈압이 유의적으로 낮았으며 신장은 유의적으로 높았다. 혈액분석 결과에서는 고스트레스군이 저스트레스군보다 공복혈당, 인슐린 저항성 지수, 중성지방, 동맥경화 지수가 유의적으로 높았다. 영양소 섭취를 분석한 결과 고스트레스군 대상자들이 저스트레스군보다 항산화 영양소인 비타민 A, 비타민 C, 비타민 E, 엽산, 아연, 카로틴을 더 적게 섭취하였다. 과일과 채소의 섭취량 또한 고스트레스군이 저스트레스군보다 유의적으로 적었다. 스트레스와 대사증후군 위험의 관계를 살펴본 결과 고스트레스군 대상자들이 저스트레스군보다 대사증후군의 교차비가 유의적으로 높았다. 결과적으로 한국 농촌 여성에서 스트레스가 높을수록 항산화 영양소와 과일 및 채소의 섭취가 적었으며 대사증후군 위험이 증가하는 것으로 나타났다.