• 제목/요약/키워드: interval regression model

검색결과 343건 처리시간 0.026초

Cardiovascular Health Metrics and All-cause and Cardiovascular Disease Mortality Among Middle-aged Men in Korea: The Seoul Male Cohort Study

  • Kim, Ji Young;Ko, Young-Jin;Rhee, Chul Woo;Park, Byung-Joo;Kim, Dong-Hyun;Bae, Jong-Myon;Shin, Myung-Hee;Lee, Moo-Song;Li, Zhong Min;Ahn, Yoon-Ok
    • Journal of Preventive Medicine and Public Health
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    • 제46권6호
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    • pp.319-328
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    • 2013
  • Objectives: This study estimated the association of cardiovascular health behaviors with the risk of all-cause and cardiovascular disease (CVD) mortality in middle-aged men in Korea. Methods: In total, 12 538 men aged 40 to 59 years were enrolled in 1993 and followed up through 2011. Cardiovascular health metrics defined the following lifestyle behaviors proposed by the American Heart Association: smoking, physical activity, body mass index, diet habit score, total cholesterol, blood pressure, and fasting blood glucose. The cardiovascular health metrics score was calculated as a single categorical variable, by assigning 1 point to each ideal healthy behavior. A Cox proportional hazards regression model was used to estimate the hazard ratio of cardiovascular health behavior. Population attributable risks (PARs) were calculated from the significant cardiovascular health metrics. Results: There were 1054 total and 171 CVD deaths over 230 690 person-years of follow-up. The prevalence of meeting all 7 cardiovascular health metrics was 0.67%. Current smoking, elevated blood pressure, and high fasting blood glucose were significantly associated with all-cause and CVD mortality. The adjusted PARs for the 3 significant metrics combined were 35.2% (95% confidence interval [CI], 21.7 to 47.4) and 52.8% (95% CI, 22.0 to 74.0) for all-cause and CVD mortality, respectively. The adjusted hazard ratios of the groups with a 6-7 vs. 0-2 cardiovascular health metrics score were 0.42 (95% CI, 0.31 to 0.59) for all-cause mortality and 0.10 (95% CI, 0.03 to 0.29) for CVD mortality. Conclusions: Among cardiovascular health behaviors, not smoking, normal blood pressure, and recommended fasting blood glucose levels were associated with reduced risks of all-cause and CVD mortality. Meeting a greater number of cardiovascular health metrics was associated with a lower risk of all-cause and CVD mortality.

선형 캘리브레이션에서 베이지안 실험계획과 기존의 최적실험계획과의 효과비교 (Performance of a Bayesian Design Compared to Some Optimal Designs for Linear Calibration)

  • 김성철
    • 응용통계연구
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    • 제10권1호
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    • pp.69-84
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    • 1997
  • 선형 캘리브레이션 실험계획 문제에 대하여, 베이지안 의사결정론을 이용하여 평균제곱오차손실을 최소화한 Kim(1988, 1993)의 실험계획과 관련 문헌의 결과인 몇 가지 최적계획을 비교한다. 비교대상 실험계획으로서 고전적 추정량의 점근분산을 최소화하는 Buonaccorsi(1986)의 최적계획, 회귀분석 모형에서 $ M(x) = \sum x_i x_i '$의 함수를 최대화 또는 최소화하는 D-optimal 또는 A-optimal 계획, Hunter and Lamboy(1981)가 베이지안 추정량의 특성을 설명하기 위하여 그 논문에서 예로 들었던 실험계획을 고려한다. 서로 다른 기준에 의한 최적계획을 비교하기 위해서 우선 기대사후분산을 계산하여 비교하고 몇가지 사전분포에 대하여 몬테칼로 시뮬레이션을 통한 평균분산과 HPD 구간의 크기를 비교한다.

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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.

Prostatic Bleeding after Prostatic Biopsy Effects Oncological Outcomes with Laparoscopic Radical Prostatectomy

  • Takai, Tomoaki;Inamoto, Teruo;Komura, Kazumasa;Tsujino, Takuya;Matsunaga, Tomohisa;Yoshikawa, Yuki;Uchimoto, Taizo;Saito, Kenkichi;Tanda, Naoki;Minami, Koichiro;Uehara, Hirofumi;Ibuki, Naokazu;Takahara, Kiyoshi;Nomi, Hayahito;Kiyama, Satoshi;Azuma, Hayahito
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1373-1377
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    • 2016
  • Background: We vigorously reviewed patients' operation record who had adhesion of the Denonvilliers' fascia and found out most of these patients had prostatic bleeding after prostatic gland biopsies. We examined the magnitude of prostatic bleeding and frequency after biopsies and the relationship with oncological outcomes. Materials and Methods: A total of 285 patients were selected for the final analyses. Inclusion criteria were as follows: receiving MRI three weeks after biopsiesand laparoscopic radical prostatectomy within 300 days after biopsy. We divided the patients into two groups with (group A) or without (group B) prostatic bleeding. We examined the magnitude of prostatic bleeding after biopsies and the relationship with operation time (OT), positive surgical margin (PSM), biochemical recurrence (BCR) and other factors. Furthermore, we created a logistic-regression model to derive a propensity score for prostatic bleeding after biopsies, which included all patient and hospital characteristics as well as selected interaction terms, and we examined the relationship with PSM and BCR. Results: In all patients, the OT in the group B was shorter than the group A (p < 0.001). Prostatic bleeding was associated with PSM (p=0.000) and BCR (p=0.036). In this propensity-matched cohort, 11 of 116 patients in the group B had PSM as compared with 36 of 116 patients from group A (match-adjusted odds ratio, 4.30; 95%CI confidence interval, 2.06 to 8.96; P=0.000). In addition, eight of 116 patients in group B encountered BCR, as compared with 18 of 116 patients in group A (match-adjusted odds ratio, 2.48; 95%CI, 1.03 to 5.96; P=0.042). Kaplan-Meier analysis in the propensity matching cohort showed a significant biochemical recurrence-free survival advantage for being free of prostate bleeding after biopsies. Conclusions: Our findings in the present cohort should help equip surgeons to pay attention to careful excision especially for those who experienced deferred prostatic bleeding.

Applicative Value of Serum CA19-9, CEA, CA125 and CA242 in Diagnosis and Prognosis for Patients with Pancreatic Cancer Treated by Concurrent Chemoradiotherapy

  • Gu, Yu-Lei;Lan, Chao;Pei, Hui;Yang, Shuang-Ning;Liu, Yan-Fen;Xiao, Li-Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권15호
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    • pp.6569-6573
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    • 2015
  • Objective: To evaluate the application value of serum CA19-9, CEA, CA125 and CA242 in diagnosis and prognosis of pancreatic cancer cases treated with concurrent chemotherapy. Materials and Methods: 52 patients with pancreatic cancer, 40 with benign pancreatic diseases and 40 healthy people were selected. The electrochemiluminescence immunoassay method was used for detecting levels of CA19-9, CEA and CA125, and a CanAg CA242 enzyme linked immunoassay kit for assessing the level of CA242. The Kaplan-Meier method was used for analyzing the prognostic factors of patients with pancreatic cancer. The Cox proportional hazard model was applied for analyzing the hazard ratio (HR) and 95% confidential interval (CI) for survival time of patients with pancreatic cancer. Results: The levels of serum CA19-9, CEA, CA125 and CA242 in patients with pancreatic cancer were significantly higher than those in patients with benign pancreatic diseases and healthy people (P<0.001). The sensitivity of CA19-9 was the highest among these, followed by CA242, CA125 and CEA. The specificity of CA242 is the highest, followed by CA125, CEA and CA19-9. The sensitivity and specificity of joint detection of serum CA19-9, CEA, CA125and CA242 were 90.4% and 93.8%, obviously higher than single detection of those markers in diagnosis of pancreatic cancer. The median survival time of 52 patients with pancreatic cancer was 10 months (95% CI7.389~12.611).. Patients with the increasing level of serum CA19-9, CEA, CA125, CA242 had shorter survival times (P=0.047. 0.043, 0.0041, 0.029). COX regression analysis showed that CA19-9 was an independent prognostic factor for patients with pancreatic cancer (P=0.001, 95%CI 2.591~38.243). Conclusions: The detection of serum tumor markers (CA19.9, CEA, CA125 and CA242) is conducive to the early diagnosis of pancreatic cancer and joint detection of tumor markers helps improve the diagnostic efficiency. Moreover, CA19-9 is an independent prognostic factor for patients with pancreatic cancer.

Genetic Parameters of Milk β-Hydroxybutyric Acid and Acetone and Their Genetic Association with Milk Production Traits of Holstein Cattle

  • Lee, SeokHyun;Cho, KwangHyun;Park, MiNa;Choi, TaeJung;Kim, SiDong;Do, ChangHee
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권11호
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    • pp.1530-1540
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    • 2016
  • This study was conducted to estimate the genetic parameters of ${\beta}$-hydroxybutyrate (BHBA) and acetone concentration in milk by Fourier transform infrared spectroscopy along with test-day milk production traits including fat %, protein % and milk yield based on monthly samples of milk obtained as part of a routine milk recording program in Korea. Additionally, the feasibility of using such data in the official dairy cattle breeding system for selection of cows with low susceptibility of ketosis was evaluated. A total of 57,190 monthly test-day records for parities 1, 2, and 3 of 7,895 cows with pedigree information were collected from April 2012 to August 2014 from herds enrolled in the Korea Animal Improvement Association. Multi-trait random regression models were separately applied to estimate genetic parameters of test-day records for each parity. The model included fixed herd test-day effects, calving age and season effects, and random regressions for additive genetic and permanent environmental effects. Abundance of variation of acetone may provide a more sensitive indication of ketosis than many zero observations in concentration of milk BHBA. Heritabilities of milk BHBA levels ranged from 0.04 to 0.17 with a mean of 0.09 for the interval between 4 and 305 days in milk during three lactations. The average heritabilities for milk acetone concentration were 0.29, 0.29, and 0.22 for parities 1, 2, and 3, respectively. There was no clear genetic association of the concentration of two ketone bodies with three test-day milk production traits, even if some correlations among breeding values of the test-day records in this study were observed. These results suggest that genetic selection for low susceptibility of ketosis in early lactation is possible. Further, it is desirable for the breeding scheme of dairy cattle to include the records of milk acetone rather than the records of milk BHBA.

조도계수와 유량의 불확실성을 고려한 청미천 유역의 홍수위 해석 (Flood stage analysis considering the uncertainty of roughness coefficients and discharge for Cheongmicheon watershed)

  • 신샛별;박지훈;송정헌;강문성
    • 한국수자원학회논문집
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    • 제50권10호
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    • pp.661-671
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    • 2017
  • 본 연구의 목적은 하천의 조도계수와 유량의 불확실성을 고려하여, 부정류 흐름에서 홍수위 해석에 미치는 영향을 정량적으로 분석하는 데 있다. 본 연구에서는 GLUE (Generalized Likelihood Uncertainty Estimation) 기법을 적용하여 조도계수와 유량의 불확실성이 홍수위 해석에 미치는 영향을 분석하고, 강우사상의 크기와 불확실성과의 관계를 분석하였다. 조도계수의 불확실성은 하천기본계획을 참고하여 0.025~0.040의 범위에서 분석하였다. 유량의 불확실성은 수위 h일 때의 유량을 Q라고 할 때, $Q=A(h-B)^C$로 표현되는 수위-유량관계식의 회귀계수 A, B, C를 통해 분석하였다. 수위-유량관계식의 회귀계수를 비선형 회귀분석을 통해 추정하였으며, 회귀계수는 t 분포를 가정하여 95% 신뢰도로 상한과 하한의 범위를 산정하였다. 산정된 회귀계수의 범위는 A는 5.138~18.442, B는 -0.524~0.104, C는 2.427~2.924로 산정되었다. 범위 내에서 10,000개의 매개변수 세트를 추출하여 HEC-RAS (Hydrologic Engineering Center's River Analysis System)에 적용하여 Monte Carlo 모의를 수행하였다. 강우사상 1~3에서 모의된 홍수위의 95% 신뢰구간의 평균적인 범위는 각각 0.39 m, 0.83 m, 0.96 m이며, 첨두 홍수위가 발생했을 때의 범위는 각각 0.52 m, 1.36 m, 1.75 m로 산정되었다. 또한 이천관측소의 1986~2015년의 일 강우에 대한 빈도해석을 수행하였으며, 수행 결과 GEV (Generalized Extreme Vlaue) 분포일 때 강우사상 1~3의 재현기간은 각각 1년, 10년, 25년 빈도에 해당되었다. 본 연구를 통해 강우사상의 크기와 불확실성의 관계를 분석하였으며, 향후 다양한 강우사상에 적용하여 검증한다면 홍수위의 불확실성을 예측하여, 하천관리 등을 위한 구조물의 계획 및 설계 시 의사 결정에 실질적인 도움이 될 수 있을 것으로 사료된다.

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.

우리나라 노인의 구강건강상태 및 관리행태와 주관적 건강상태와의 관련성: 제7기 국민건강영양조사(2016-2018)를 이용하여 (Oral Health Status and Behavior Factors Associated with Self-Rated Health Status among the Elderly in South Korea: The 7th Korea National Health and Nutrition Examination Survey (2016-2018))

  • 홍주희;이용재;김태현;김노을;정우진
    • 보건행정학회지
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    • 제31권1호
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    • pp.74-90
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    • 2021
  • Background: It is getting important to improve the oral health status of the elderly because oral health status may affect their health status of the whole body. In this respect, we aimed to explore the association of oral health status and behavior factors with self-rated health status by sex. Methods: Using the data from the 7th Korea National Health and Nutrition Examination Survey for health surveys and oral examinations (2016-2018), we analyzed a total of 3,070 people aged 65 or older (men: 1,329; women: 1,741). Our dependent variable, self-rated health status, was divided into two groups: not good (bad and very bad) and good (very good, good, and fair), whereas our independent variables of interest were oral health status and behavior factors. In addition to descriptive analysis and the Rao-Scott chi-square test, reflecting survey characteristics, we conducted hierarchical multivariable logistic regression analyses adjusted for socio-demographics and health status and behavior factors. All analyses were stratified by sex. Results: The proportion of people having 'not good' self-rated health was 36.5% in women but 24.5% in men. In a model adjusted for all covariates, the self-rated health status showed significant association with the self-rated oral health status. For example, in men, the risk of having 'not good' self-rated health was high in people having 'poor' (odds ratio [OR], 5.31; 95% confidence interval [CI], 2.34-12.03) self-rated oral health status and in those having 'fair' (OR, 4.03; 95% CI, 1.68-9.70) in comparison with those having 'good' self-rated oral health status. Dental status regarding speaking difficulty seemed to be very important in influencing self-rated health status. For instance, in women, compared to people having 'no discomfort' speaking difficulty, the risk of having 'not good' self-rated health was high in people having 'not bad' (OR, 1.60; 95% CI, 1.14-2.24) and 'discomfort' (OR, 1.79; 95% CI, 1.30-2.47) speaking difficulty. The covariates significantly associated with the risk of having 'not good' self-rated health were: physical activity, chronic disease, stress, and body mass index in both sexes; health insurance type and drinking only in men; and economic activity only in women. Conclusion: Oral health status and behavioral factors were associated with self-rated health status among the elderly, differently by sex. This suggests that public health policies toward better health in the elderly should take their oral health status and oral health behaviors into account in a sex-specific way.

Ki67 Index Is the Most Powerful Factor for Predicting the Recurrence in Atypical Meningioma : Retrospective Analysis of 99 Patients in Two Institutes

  • Lee, Sang Hyuk;Lee, Eun Hee;Sung, Kyoung Su;Kim, Dae Cheol;Kim, Young Zoon;Song, Young Jin
    • Journal of Korean Neurosurgical Society
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    • 제65권4호
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    • pp.558-571
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    • 2022
  • Objective : The primary objective of this study was to identify predicting factors for local control (LC) of atypical meningioma, and we validated them with comparing the predicting factors for recurrence-free survival (RFS). We also examined the rate of LC after surgical resection with or without adjuvant treatment and RFS. Methods : Clinical and radiological records of patients with atypical meningiomas diagnosed at two institutes from January 2000 to December 2018 were reviewed retrospectively. Histopathological features were also reviewed using formalin-fixed paraffin embedded samples from pathological archives. Results : Of the 99 atypical meningiomas eligible for analysis, 36 (36.4%) recurred during the follow-up period (mean, 83.3 months; range, 12-232 months). The rate of 3-year LC and 5-year LC was 80.8% and 74.7%, respectively. The mean time-to-recurrence was 49.4 months (range, 12-150). The mean RFS was 149.3 months (95% confidence interval, 128.8-169.8 months) during the mean follow-up duration of 83.3 months (range, 12-232 months). Multivariate analysis using Cox proportional-hazard regression model showed that the extent of resection (hazard ratio [HR], 4.761; p=0.013), Ki67 index (HR, 8.541; p=0.004), mitotic index (HR, 3.275; p=0.044), and tumor size (HR, 3.228; p=0.041) were independently associated with LC. These factors were also statistically associated with RFS. In terms of radiotherapy after surgical resection, the recurrence was not prevented by immediate radiotherapy because of the strong effect of proliferative index on recurrence. Conclusion : The present study suggests that the extent of resection, proliferative index (according to Ki67 expression) and mitotic index, and tumor size are associated with recurrence of atypical meningiomas. However, our results should be further validated through prospective and randomized clinical trials to overcome the inborn bias of retrospective nature of the study design.