• 제목/요약/키워드: Cohort model

검색결과 382건 처리시간 0.028초

Nested Case-control Study of Occupational Radiation Exposure and Breast and Esophagus Cancer Risk among Medical Diagnostic X Ray Workers in Jiangsu of China

  • Wang, Fu-Ru;Fang, Qiao-Qiao;Tang, Wei-Ming;Xu, Xiao-San;Mahapatra, Tanmay;Mahapatra, Sanchita;Liu, Yu-Fei;Yu, Ning-Le;Sun, Quan-Fu
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4699-4704
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    • 2015
  • Medical diagnostic X-ray workers are one occupational group that expose to the long-term low-dose external radiation over their working lifetime, and they may under risk of different cancers. This study aims to determine the relationship between the occupational X-ray radiation exposure and cancer risk among these workers in Jiangsu, China. We conducted Nested case-control study to investigate the occupational X-ray radiation exposure and cancer risk. Data were collected through self-administered questionnaire, which includes but not limits to demographic data, personal behaviors and family history of cancer. Retrospective dose reconstruction was conducted to estimate the cumulative doses of the x-ray workers. Inferential statistics, t-test and 2 tests were used to compare the differences between each group. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of cancer by adjusting the age, gender. All 34 breast cancer cases and 45 esophageal cancer cases that detected in a cohort conducted among health workers between 1950~2011 were included in this presented study, and 158 cancer-free controls were selected by frequency-matched (1:2). Our study found that the occupational radiation exposure was associated with a significantly increased cancer risk compared with the control, especially in breast cancer and esophageal cancer (adjusted OR=2.90, 95% CI: 1.19-7.04 for breast cancer; OR=4.19, 95% CI: 1.87-9.38 for esophageal cancer, and OR=3.43, 95% CI: 1.92-6.12 for total cancer, respectively). The occupational X-ray radiation exposure was associated with increasing cancer risk, which indicates that proper intervention and prevention strategies may be needed in order to bring down the occupational cancer risk.

Lack of Association between the Klotho Gene and COPD

  • Kim, Woo-Jin;Oh, Yeon-Mok;Kim, Tae-Hyung;Lee, Ji-Hyun;Kim, Eun-Kyung;Lee, Jin-Hwa;Lee, Sang-Min;Shin, Tae-Rim;Yoon, Ho-Il;Lim, Seong-Yong;Lee, Sang-Do
    • Tuberculosis and Respiratory Diseases
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    • 제71권4호
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    • pp.254-258
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    • 2011
  • Background: Although the aging process and features of chronic obstructive pulmonary disease (COPD) have several similarities, the relationship between aging and COPD pathogenesis remains incompletely understood. The klotho gene was found to be related to premature aging and emphysematous changes in an animal model. We investigated whether klotho gene polymorphisms are related to COPD susceptibility and emphysema severity. Methods: A total of 219 COPD subjects from the Korean Obstructive Lung Disease Cohort and 305 control subjects were genotyped for two single nucleotide polymorphisms (SNPs) of the klotho gene associated with coronary artery disease. Logistic regression was performed to determine the association of these SNPs with COPD susceptibility and linear regression was performed to investigate their association with emphysema severity in COPD subjects. Results: The mean age of the COPD subjects was 66 years and their mean FEV1 was 1.46 L. There were no associations between either SNP or COPD susceptibility (p=0.6 and 0.2, respectively) and there were no associations with emphysema severity. Conclusion: Genetic polymorphisms of the klotho gene were not associated with COPD in a Korean population.

우리나라 성인 남성에서 흡연량과 공복혈당장애 또는 제2형 당뇨병 발생과의 연관성 (The Effect of Smoking Status upon Occurrence of Impaired Fasting Glucose or Type 2 Diabetes in Korean Men)

  • 박창해;가혁;임종환;곽승민;김환철;최지호
    • Journal of Preventive Medicine and Public Health
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    • 제41권4호
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    • pp.249-254
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    • 2008
  • Objectives: To investigate whether smoking and the smoking status are predictors of the incident impaired fasting glucose (IFG) or type 2 diabetes in Korean men. Methods: A cohort of 1,717 Korean men without IFG or diabetes, who underwent annual periodic health examinations for 4 years (2002-2006), were retrospectively investigated. IFG and diabetes were defined as a serum fasting glucose concentration of 100-125 mg/dL and more than 126 mg/dL, respectively. Cox's proportional hazards model was used to evaluate the association between smoking and development of IFG or type 2 diabetes. Results: A total of 558 cases (32.5%) of incident IFG and 50 cases (2.9%) of diabetes occurred. After controlling for the potential predictors of diabetes, the relative risk for IFG, compared with the never smokers, was 1.02 (95% CI=0.88 to 1.19) for the ever-smokers, 0.96 (95% CI=0.79-1.16) for those who smoked 1-9 cigarettes/d, 1.15 (95% CI=1.01 to 1.30) for those who smoked 10-19 cigarettes/d, and 1.31 (95% CI=1.10 to 1.57) for those who smoked 20 or more cigarettes/d (the P value for the current smokers was only p<0.002). The respective multivariate adjusted relative risks for type 2 diabetes, compared with the never-smokers, were 1.07 (95% CI=0.64 to 1.92), 1.47 (95% CI=0.71 to 3.04), 1.84 (95% CI=0.92-3.04), and 1.87 (95% CI=1.13-3.67), respectively (the P value for the current smokers was only p=0.004). Conclusions: The smoking status and the number of cigarettes smoked daily are associated with an increased risk for developing IFG or type 2 diabetes in Korean men.

Predictive Value of IHC4 Score for Pathological Response to Neoadjuvant Chemotherapy in Hormone Receptor-Positive Breast Cancer

  • Elsamany, Shereef;Elmorsy, Soha;Alzahrani, Abdullah;Rasmy, Ayman;Abozeed, Waleed N;Mohammed, Amrallah A;Sherisher, Mohamed A;Abbas, Mohammed M;Mashhour, Miral
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7975-7979
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    • 2015
  • Purpose: This study aimed to explore the value of IHC4 in predicting pathological response after neoadjuvant chemotherapy in patients with hormonal receptor (HR)-positive breast cancer (BC). Materials and Methods: In this retrospective exploratory study, data for 68 HR-positive BC patients who received neoadjuvant chemotherapy were recorded. IHC4 scores were calculated based on estrogen receptors/progesterone receptors, Ki-67 and HER2 status. Logistic and ordinal regression analyses in addition to likelihood ratio test were used to explore associations of IHC4 scores and other clinico-pathological parameters with pathological complete response (pCR) and pathological stage. Results: Taking the 25th percentile as the cut-off, a lower IHC4 score was associated with an increased probability of pCR (low; 52.9% vs. High; 21.6%, OR=4.1, 95% CI=1.28-13.16, p=0.018) and a lower pathological stage (OR=3.9, 95% CI=1.34-11.33, p=0.012). When the IHC4 score was treated as a continuous variable, a lower score was again associated with an increased probability of pCR (OR=1.010, 95% CI=1.001-1.018, p=0.025) and lower pathological stage (OR=1.009, 95% CI=1.002-1.017, P=0.008). Lower clinical stage was associated with a better pCR rate that was of borderline significance (P=0.056). When clinical stage and IHC4 score were incorporated together in a logistic model, the likelihood ratio test gave a P-value of 0.004 after removal of the IHC4 score and 0.011 after removal of the stage, indicating a more significant predictive value of the IHC4 score for pCR. Conclusions: This study suggests that the IHC4 score can predict pathological response to neoadjuvant chemotherapy in HR-positive BC patients. This finding now needs to be validated in a larger cohort of patients.

러프 하한 근사를 갖는 로컬 커버링 기반 규칙 획득 기법을 이용한 섬망 환자의 분류 방법 (A Classification Method of Delirium Patients Using Local Covering-Based Rule Acquisition Approach with Rough Lower Approximation)

  • 손창식;강원석;이종하;문경자
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제9권4호
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    • pp.137-144
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    • 2020
  • 섬망은 의식 장애, 주의력 장애 및 언어력 장애와 같은 일시적인 인지 장애가 있는 환자, 특히 노인에서 나타나는 가장 흔한 정신 장애 중 하나이다. 섬망은 환자와 가족에게 고통을 주고, 통증과 같은 증상의 관리를 방해할 수 있으며 노인 사망률 증가와 관련이 있다. 본 논문의 목적은 장기 요양 시설에서 섬망 환자를 구별하는데 사용될 수 있는 유용한 임상적 지식을 생성하는데 있다. 이러한 목적을 위해, 러프 하한 근사 영역을 갖는 로컬 커버링 규칙 기법을 활용하여 섬망과 관련된 임상적 분류 지식을 추출하였다. 제안된 방법의 임상적 적용 가능성은 전향적 코호트 연구로부터 수집된 데이터를 활용하여 확인하였다. 연구 결과, 섬망 기간이 12일 이상 지속될 수 있는 6가지 유용한 임상적 증거를 발견하였고, 체질량 지수, 동반질환 지수, 입원경로, 영양결핍, 감염, 수면박탈, 욕창, 기저귀 사용과 같은 8가지 인자들이 섬망 결과를 구별하는 데 중요한 요인이라는 것을 확인하였다. 제안된 방법의 분류 성능은 통계적 5-겹 교차검정 방법을 사용하여 3가지 벤치마킹 모델, 즉 ANN, RBF 커널 함수를 활용한 SVM, 랜덤 포레스트와 비교하여 검증하였다. 제안된 방법은 3가지 모델 중 가장 높은 성능을 제공한 SVM 모델과 비교했을 때 정확도와 AUC 기준에서 평균 0.6%와 2.7% 개선된 성능을 보였다.

우리나라 성인에서 혈청 지질성분비가 허혈성 심장질환 발생에 미치는 위험도 평가: 코호트 연구 (Associations of Serum Lipid Profiles with Incidence of Ischemic Heart Diseases in Korean Adults: Retrospective Cohort Study)

  • 신숙희;이태용
    • 한국산학기술학회논문지
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    • 제13권5호
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    • pp.2219-2231
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    • 2012
  • 본 연구에서는 우리나라 30세 이상 성인들의 허혈성심장질환(ischemic heart disease, IHD) 발생률을 계산하고, 지질지표(콜레스테롤, 중성지방, 고밀도지단백콜레스테롤, 저밀도지단백콜레스테롤)가 허혈성심장질환 발생에 미치는 위험도를 파악하고자 19개 대학 및 종합병원의 건강검진센터에서 검진을 받은 417,642명을 대상으로 1993년 9월부터 2009년 6월까지 평균 8.5년동안 허혈성심장질환의 발생을 추적관찰하였다. 자료수집은 검진자들에 대한 설문조사지를 이용하였고, 허혈성심장질환의 발생여부는 국민건강보험공단의 데이터베이스에서 확인하였다. 발생률은 발생밀도로 계산하였고, 혈청지질 지표에 따른 허혈성심장질환의 발생 위험도는 콕스의 비례위험 회귀모형을 이용하여 연령, BMI, 생활양식을 보정한 상태에서 성별에 따른 위험요인별 위험비와 95% 신뢰구간을 계산하였다. 연구결과 TC/HDL 비의 증가에 따라 IHD의 발생 위험비는 남자에서 1.21배에서 1.84배까지, 여자는 1.26배에서 1.86배까지 증가하였으며, TG/HDL 비의 증가에 따른 IHD의 발생 위험비는 남자에서 1.17배에서 1.49배까지, 여자는 1.42배에서 1.97배까지, LDL/HDL 비에 따라 IHD의 발생 위험비는 남자에서 1.26배에서 1.82배까지, 여자는 1.26배에서 1.68배까지 증가하였다. 결론적으로 혈청지질지표는 심혈관질환의 중요한 위험요인으로 총콜레스테롤, 저밀도지단백콜레스테롤, 중성지방은 혈중 농도가 높을수록, 고밀도지단백콜레스테롤은 낮을수록 IHD의 위험이 높아지는 것으로 나타났고, TC/HDL 비, TG/HDL 비, LDL/HDL 비에서 단독의 지질지표보다 위험도가 더 높게 나타나는 경향이 있었다. 따라서 추후 허혈성 심장질환의 예방 및 관리에는 혈청지질지표의 비도 감안하여야 한다.

한국 여성의 생애 유형: 저출산과 M자형 취업곡선에의 함의 (Patterns of Korean Women′s Life Course)

  • 박경숙;김영혜
    • 한국인구학
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    • 제26권2호
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    • pp.63-90
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    • 2003
  • 이 연구는 결혼, 출산, 취업 시기와 순서에 기초하여 한국 여성의 생애과정의 유형적 특성을 분석하고 있다. 또한 생애 유형의 변화와 집단간 차이에 유의하면서 결혼코호트와 여성의 가족ㆍ개인 특성에 따라 생애 유형의 차이를 설명하고 있다. 분석에 활용한 자료는 2002년 한국여성개발원이 조사한 '제4차 여성 취업실태조사'이다. 초혼 경험이 있는 기혼 여성의 생애는 크게 다섯 유형으로 구분되었다. 결혼과 출산기간에도 쉬지 않고 계속 일한 여성(일ㆍ가족역할 중복형, 13.7%), 결혼 전에 일하였지만 출산/육아기간 동안 일을 그만두고 공백기 이후 다시 일자리로 돌아온 여성(M형, 18.6%), 결혼과 출산 직후 일을 그만 둔 여성(잠재 M형, 26.9%), 결혼 전에 일한 경험이 없지만 결혼/육아 이후 일자리를 처음 가진 여성(양육 후 입직형, 23.5%), 마지막으로 전혀 일한 경험이 없는 여성(17.3%)이다. 각 생애유형의 상대적 구성은 결혼코호트에 따라 유의한 차이가 존재하였다 최근의 결혼코호트일수록 M형(잠재 M형 포함)이 지배적인 생애 유형이 되고 있다. 양육 후 처음 일을 하거나, 전혀 일한 경험이 없는 기혼여성의 비율은 최근 결혼코호트일수록 작아지고 있다. 또한 1990년 이후 결혼한 여성에서 일가족 중복형의 생애 패턴이 증가하는 경향이 확인된다. 동일 코호트 내에서 살펴보면, 생애 유형은 여성의 교육수준 성장기 일하는 여성의 역할 모델의 존재(어머니의 취업), 남편과 여성의 성역할태도, 가구의 주 생업에 따라 유의미한 차이가 나타났다. 마지막으로 여성의 생애유형별 일과 가족역할의 의미를 조망하고 있다.

External validation of IBTR! 2.0 nomogram for prediction of ipsilateral breast tumor recurrence

  • Lee, Byung Min;Chang, Jee Suk;Cho, Young Up;Park, Seho;Park, Hyung Seok;Kim, Jee Ye;Sohn, Joo Hyuk;Kim, Gun Min;Koo, Ja Seung;Keum, Ki Chang;Suh, Chang-Ok;Kim, Yong Bae
    • Radiation Oncology Journal
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    • 제36권2호
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    • pp.139-146
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    • 2018
  • Purpose: IBTR! 2.0 nomogram is web-based nomogram that predicts ipsilateral breast tumor recurrence (IBTR). We aimed to validate the IBTR! 2.0 using an external data set. Materials and Methods: The cohort consisted of 2,206 patients, who received breast conserving surgery and radiation therapy from 1992 to 2012 at our institution, where wide surgical excision is been routinely performed. Discrimination and calibration were used for assessing model performance. Patients with predicted 10-year IBTR risk based on an IBTR! 2.0 nomogram score of <3%, 3%-5%, 5%-10%, and >10% were assigned to groups 1, 2, 3, and 4, respectively. We also plotted calibration values to observe the actual IBTR rate against the nomogram-derived 10-year IBTR probabilities. Results: The median follow-up period was 73 months (range, 6 to 277 months). The area under the receiver operating characteristic curve was 0.607, showing poor accordance between the estimated and observed recurrence rate. Calibration plot confirmed that the IBTR! 2.0 nomogram predicted the 10-year IBTR risk higher than the observed IBTR rates in all groups. High discrepancies between nomogram IBTR predictions and observed IBTR rates were observed in overall risk groups. Compared with the original development dataset, our patients had fewer high grade tumors, less margin positivity, and less lymphovascular invasion, and more use of modern systemic therapies. Conclusions: IBTR! 2.0 nomogram seems to have the moderate discriminative ability with a tendency to over-estimating risk rate. Continued efforts are needed to ensure external applicability of published nomograms by validating the program using an external patient population.

Skeletal stability following mandibular advancement: is it influenced by the magnitude of advancement or changes of the mandibular plane angle?

  • Tabrizi, Reza;Nili, Mahsa;Aliabadi, Ehsan;Pourdanesh, Fereydoun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제43권3호
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    • pp.152-159
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    • 2017
  • Objectives: The aim of this study was to investigate the effects of advancement magnitude and changes in mandibular plane angle on the stability of mandibular advancement. Materials and Methods: This retrospective cohort study evaluated the postoperative stability of mandibular advancement in class II skeletal subjects who underwent bilateral sagittal split osteotomy. Radiographs taken preoperatively, immediately postoperatively and 1 year postoperatively were traced and analyzed using linear and angular measurements. To determine horizontal and vertical relapse, an X-Y coordinate system was established in which the X-axis was constructed by rotating S-N downward by $7^{\circ}$ (approximation of the Frankfort horizontal plane) and the Y-axis was defined as a line perpendicular to the X-axis and passing through the point Sella. For certain reference points including point A, point B, pogonion and menton, the perpendicular distance between each point and both axes was determined and cephalometric variables were recorded as X and Y coordinates. Results: Twenty-five subjects were studied. A significant correlation between the amount of mandibular advancement and relapse in the B point (vertical and horizontal) and the pogonion point was observed (vertical and horizontal, P<0.001). Evaluation of data demonstrated a positive correlation between the mandibular plane angle (SN/ML) change and vertical relapse in the B point (P<0.05). A simple regression model demonstrated that 74% of horizontal relapse and 42.3% of vertical relapse in the B point was related to the amount of mandibular advancement. The receiver operating characteristic test showed that 8.5 mm mandibular advancement is related to a relapse rate of 1 mm or more in the pogonion, vertically or horizontally. Conclusion: The magnitude of mandibular advancement is a stronger surgical predictor for horizontal rather than vertical relapse at the B point. Changes in mandibular plane angle (SN/ML) during surgery affect vertical, but not horizontal relapse at the B point.

Associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans

  • Kim, Sung Hee;Park, Yeong Mi;Choi, Bo Youl;Kim, Mi Kyung;Roh, Sungwon;Kim, Kyunga;Yang, Yoon Jung
    • Nutrition Research and Practice
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    • 제12권2호
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    • pp.160-165
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    • 2018
  • BACKGROUND/OBJECTIVES: Korea is quickly becoming an aged society. Dementia is also becoming a vital public health problem in Korea. Cognitive impairment as a pre-stage of dementia shares most risk factors for dementia. The aim of the present study was to determine associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans. SUBJECTS/METHODS: In this cross-sectional study, a total of 230 participants aged 60-79 years from Yangpyeong cohort were included. Cognitive function was assessed by the Korean version of the Mini-Mental State Examination for Dementia Screening. The logistic multivariable regression model was applied to determine the effect of serum vitamins A, C, and E on the risk of cognitive impairment. RESULTS: There was no significant association between the risk of cognitive impairment and serum levels of vitamin A and vitamin C. There was a significant odd ratio when the second tertile group of beta-gamma tocopherol level was compared to the first tertile group [odds ratio (OR) = 0.37, 95% confidence interval (CI) = 0.14-0.98, P for trend = 0.051]. In subgroup analyses, there were significant negative associations between beta-gamma tocopherol level and the risk of cognitive impairment in men (OR = 0.17, 95% CI = 0.03-0.87, P for trend = 0.028), non-drinkers or former drinkers (OR = 0.13, 95% CI = 0.02-0.66, P for trend = 0.025), and non-smokers or former smokers (OR = 0.27, 95% CI = 0.09-0.82, P for trend = 0.017). CONCLUSION: Serum beta-gamma tocopherol levels tended to be inversely associated with the risk of cognitive impairment. Further prospective large-scaled studies are needed to examine this association.