• Title/Summary/Keyword: Cohort model

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A Risk Prediction Model for Operative Mortality after Heart Valve Surgery in a Korean Cohort

  • Kim, Ho Jin;Kim, Joon Bum;Kim, Seon-Ok;Yun, Sung-Cheol;Lee, Sak;Lim, Cheong;Choi, Jae Woong;Hwang, Ho Young;Kim, Kyung Hwan;Lee, Seung Hyun;Yoo, Jae Suk;Sung, Kiick;Je, Hyung Gon;Hong, Soon Chang;Kim, Yun Jung;Kim, Sung-Hyun;Chang, Byung-Chul
    • Journal of Chest Surgery
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    • 제54권2호
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    • pp.88-98
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    • 2021
  • Background: This study aimed to develop a new risk prediction model for operative mortality in a Korean cohort undergoing heart valve surgery using the Korea Heart Valve Surgery Registry (KHVSR) database. Methods: We analyzed data from 4,742 patients registered in the KHVSR who underwent heart valve surgery at 9 institutions between 2017 and 2018. A risk prediction model was developed for operative mortality, defined as death within 30 days after surgery or during the same hospitalization. A statistical model was generated with a scoring system by multiple logistic regression analyses. The performance of the model was evaluated by its discrimination and calibration abilities. Results: Operative mortality occurred in 142 patients. The final regression models identified 13 risk variables. The risk prediction model showed good discrimination, with a c-statistic of 0.805 and calibration with Hosmer-Lemeshow goodness-of-fit p-value of 0.630. The risk scores ranged from -1 to 15, and were associated with an increase in predicted mortality. The predicted mortality across the risk scores ranged from 0.3% to 80.6%. Conclusion: This risk prediction model using a scoring system specific to heart valve surgery was developed from the KHVSR database. The risk prediction model showed that operative mortality could be predicted well in a Korean cohort.

Noncontrast Computed Tomography-Based Radiomics Analysis in Discriminating Early Hematoma Expansion after Spontaneous Intracerebral Hemorrhage

  • Zuhua Song;Dajing Guo;Zhuoyue Tang;Huan Liu;Xin Li;Sha Luo;Xueying Yao;Wenlong Song;Junjie Song;Zhiming Zhou
    • Korean Journal of Radiology
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    • 제22권3호
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    • pp.415-424
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    • 2021
  • Objective: To determine whether noncontrast computed tomography (NCCT) models based on multivariable, radiomics features, and machine learning (ML) algorithms could further improve the discrimination of early hematoma expansion (HE) in patients with spontaneous intracerebral hemorrhage (sICH). Materials and Methods: We retrospectively reviewed 261 patients with sICH who underwent initial NCCT within 6 hours of ictus and follow-up CT within 24 hours after initial NCCT, between April 2011 and March 2019. The clinical characteristics, imaging signs and radiomics features extracted from the initial NCCT images were used to construct models to discriminate early HE. A clinical-radiologic model was constructed using a multivariate logistic regression (LR) analysis. Radiomics models, a radiomics-radiologic model, and a combined model were constructed in the training cohort (n = 182) and independently verified in the validation cohort (n = 79). Receiver operating characteristic analysis and the area under the curve (AUC) were used to evaluate the discriminative power. Results: The AUC of the clinical-radiologic model for discriminating early HE was 0.766. The AUCs of the radiomics model for discriminating early HE built using the LR algorithm in the training and validation cohorts were 0.926 and 0.850, respectively. The AUCs of the radiomics-radiologic model in the training and validation cohorts were 0.946 and 0.867, respectively. The AUCs of the combined model in the training and validation cohorts were 0.960 and 0.867, respectively. Conclusion: NCCT models based on multivariable, radiomics features and ML algorithm could improve the discrimination of early HE. The combined model was the best recommended model to identify sICH patients at risk of early HE.

유방암 조기경고체계 개발을 위한 코호트 구축 - 일 농촌지역 여성을 중심으로 - (Study of Cohort Construction for Development of Early Alarm System (EMS) for Breast Cancer - based on women living in a rural area -)

  • 허혜경;박소미;김기연;이해종;전은표
    • 성인간호학회지
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    • 제18권1호
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    • pp.146-156
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    • 2006
  • Purpose: 1) to construct cohorts according to risk scores calculated with the Gail Breast Cancer Risk Assessment Tool (Gail et al., 1989) (Gail) and the Breast Cancer Risk Appraisal (Lee et al,. 2003) (Lee) 2) to identify the distribution of risk factors and preventive behavior stages between the cohorts 3) to identify abnormal breast conditions in risk cohort. Method: Using convenience sampling, 775 rural women were selected. Risk appraisal was scored using Gail and Lee. Preventive behavior stages for BSE (Breast self examination) and mammography were measured using 4 stages of the Transtheoretical Model (Prochaska & DiClemente, 1983). Results: 1) The risk cohort according to Gail was 12.3% (n=95), and Lee, 3.1% (n=24). 2) There were significant differences in the distribution of risk factors (age, family history, age at 1st live birth, age at menarche, number of breast biopsy, history of breast disease, and breast-feeding) between cohorts. 3) There was a significant difference in the distribution of the stage of BSE according to Lee. 4) Six women in the risk group detected masses or nodules and physician consultation and ultrasonography were recommended. Conclusion: On the basis of the constructed cohorts, further longitudinal studies of cohorts are recommended with interventions according to characteristics of cohorts.

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Time Trends of Esophageal Cancer Mortality in Linzhou City During the Period 1988-2010 and a Bayesian Approach Projection for 2020

  • Liu, Shu-Zheng;Zhang, Fang;Quan, Pei-Liang;Lu, Jian-Bang;Liu, Zhi-Cai;Sun, Xi-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4501-4504
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    • 2012
  • In recent decades, decreasing trends in esophageal cancer mortality have been observed across China. We here describe esophageal cancer mortality trends in Linzhou city, a high-incidence region of esophageal cancer in China, during 1988-2010 and make a esophageal cancer mortality projection in the period 2011-2020 using a Bayesian approach. Age standardized mortality rates were estimated by direct standardization to the World population structure in 1985. A Bayesian age-period-cohort (BAPC) analysis was carried out in order to investigate the effect of the age, period and birth cohort on esophageal cancer mortality in Linzhou during 1988-2010 and to estimate future trends for the period 2011-2020. Age-adjusted rates for men and women decreased from 1988 to 2005 and changed little thereafter. Risk increased from 30 years of age until the very elderly. Period effects showed little variation in risk throughout 1988-2010. In contrast, a cohort effect showed risk decreased greatly in later cohorts. Forecasting, based on BAPC modeling, resulted in a increasing burden of mortality and a decreasing age standardized mortality rate of esophageal cancer in Linzhou city. The decrease of esophageal cancer mortality risk since the 1930 cohort could be attributable to the improvements of socialeconomic environment and lifestyle. The standardized mortality rates of esophageal cancer should decrease continually. The effect of aging on the population could explain the increase in esophageal mortality projected for 2020.

Body Mass Index Effects on Risk of Ovarian Cancer: A Meta-Analysis

  • Poorolajal, Jalal;Jenabi, Ensiyeh;Masoumi, Seyyedeh Zahra
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7665-7671
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    • 2014
  • Objectives: The association between body mass index (BMI) and ovarian cancer risk is unclear and requires further investigation. The present meta-analysis was conducted to assess the effect of overweight and obesity on ovarian cancer risk in the premenopausal and postmenopausal periods. Data sources: Major electronic databases were searched until February 2014 including Medline and Scopus. Reference lists and relevant conference databases were searched and the authors were contacted for additional unpublished references. Review Methods: All cohort and case-control studies addressing the effect of BMI on ovarian cancer were included, irrespective of publication date and language. The effect measure of choice was risk ratio (RR) for cohort studies and odds ratio (OR) for case-control studies. The results were reported using a random effects model with 95% confidence intervals (CIs). Results: Of 3,776 retrieved studies, 19 were ultimately analyzed including 10 cohort studies involving 29,237,219 person-years and 9 case-control studies involving 96,965 people. The results of both cohort and case-control studies showed being overweight and obesity increased the risk of ovarian cancer compared to women with normal weight during both premenopausal and postmenopausal periods: RR=1.08 (95%CI: 0.97, 1.19) and OR=1.26 (95%CI: 0.97, 1.63) for overweight and RR=1.27 (95%CI: 1.16, 1.38) and OR=1.26 (95%CI: 1.06, 1.50) for obesity. Conclusions: There is sufficient evidence that an increase in BMI can increase the risk of ovarian cancer regardless of the menopausal status, mimicking a dose-response relationship although the association is not very strong.

Depression and the Risk of Breast Cancer: A Meta-Analysis of Cohort Studies

  • Sun, Hui-Lian;Dong, Xiao-Xin;Cong, Ying-Jie;Gan, Yong;Deng, Jian;Cao, Shi-Yi;Lu, Zu-Xun
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3233-3239
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    • 2015
  • Background: Whether depression causes increased risk of the development of breast cancer has long been debated. We conducted an updated meta-analysis of cohort studies to assess the association between depression and risk of breast cancer. Materials and Methods: Relevant literature was searched from Medline, Embase, Web of Science (up to April 2014) as well as manual searches of reference lists of selected publications. Cohort studies on the association between depression and breast cancer were included. Data abstraction and quality assessment were conducted independently by two authors. Random-effect model was used to compute the pooled risk estimate. Visual inspection of a funnel plot, Begg rank correlation test and Egger linear regression test were used to evaluate the publication bias. Results: We identified eleven cohort studies (182,241 participants, 2,353 cases) with a follow-up duration ranging from 5 to 38 years. The pooled adjusted RR was 1.13(95% CI: 0.94 to 1.36; $I^2=67.2%$, p=0.001). The association between the risk of breast cancer and depression was consistent across subgroups. Visual inspection of funnel plot and Begg's and Egger's tests indicated no evidence of publication bias. Regarding limitations, a one-time assessment of depression with no measure of duration weakens the test of hypothesis. In addition, 8 different scales were used for the measurement of depression, potentially adding to the multiple conceptual problems concerned with the definition of depression. Conclusions: Available epidemiological evidence is insufficient to support a positive association between depression and breast cancer.

흡연과 음주가 남성 암 사망에 미치는 영향: 강화 코호트 연구 (Cigarette Smoking, Alcohol and Cancer Mortality in Men: The Kangwha Cohort Study)

  • 이상규;남정모;이상욱;오희철
    • Journal of Preventive Medicine and Public Health
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    • 제35권2호
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    • pp.123-128
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    • 2002
  • Objective : To examine the relationship between cigarette smoking, alcohol and cancer mortality in men in the Kangwha cohort after 12 years and 10 months of follow up. Methods : The subjects consisted of 2,681 men in the Kangwha cohort aged over 55 in 1985. Number of deaths and the time to death front all cancers and other cause were measured and the data for the smoking and drinking habits were obtained from the baseline survey data in 1985. All subjects were categorized into four groups according to their smoking habits: non-smokers, ex-smokers, mode(ate-smokers (1-19 cigarettes per day), heavy-smokers ($\geq$20 cigarettes per day). In addition, they were also categorized according to their drinking habits: non-drinkers, light-drinkers ($\leq$1 drink per week), moderate-drinkers (<3 drinks per day), heavy-drinkers ($\geq$3 drinks per day). The cancer specific death rates were calculated according to their smoking and drinking status. The adjusted risk ratio for all cancer deaths according to their smoking and drinking status were estimated using the Cox's proportional hazard regression model. Results : Using nonsmokers as the reference category, the adjusted risk ratio for all cancer deaths were 1.573(95% CI=1.003-2.468) for heavy-smokers. For lung cancer deaths, the adjusted risk ratios were 3.540(95% CI=1.251-10.018) for moderate-smoker and 4.114(95% CI=1.275-13.271) for heavy-smokers. Compared to non-drinkers, the adjusted risk ratio for stomach cancer was 2.204(95% CI=1.114-4.361) for light-drinkers. Conclusion : Smoking is the most significant risk factor for cancer deaths particularly lung cancer.

폐경 연령과 사망력과의 관계에 대한 코호트 연구 - 강화 코호트 연구 - (Cohort Study on Age at Menopause and Mortality - Kangwha Cohort Study -)

  • 홍재석;이상욱;지선하;손태용;오희철
    • Journal of Preventive Medicine and Public Health
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    • 제34권4호
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    • pp.323-330
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    • 2001
  • Objective : To examine the association between age at menopause and mortality in a population-based sample of women in Kangwha, Korea. Methods : From the Kangwha Cohort, followed-up from 1985 to 1999, the data of the over 55 year old female group(n=3,596) was used in this study to examine the association between age at menopause and mortality. We calculated the all causes mortality risk ratio and the cancer mortality risk ratio by age at menopause grouping using the Cox Proportional Hazards Model with adjustments for age, BMI, smoking, education, chronic disease, self-rated health status, alcohol consumption and age at first birth. Result and conclusion : Compared to women who had menopause at 45-49 years, the all causes mortality risk ratio was 1.24 for women with menopause at less than 40 years(95% CI=1.01-1.53) and 1.05 for women with menopause at over 50 years(95% CI=0.92-1.20). Also, compared to women who had menopause at 45-49 years, the cancer mortality risk ratio was 1.53 for women with menopause at less than 40 years(95% CI=0.78-2.98) and 1.17 for women with menopause at over 50 years(95% CI=0.77-1.80).

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여성 노인에서 출산력과 고관절 골절 발생간의 관련성 : 코호트 연구 (Reproductive History and Hip Fracture in the Elderly Women in Korea : A Cohort Study)

  • 이승미;김윤이;윤경은;박병주
    • Journal of Preventive Medicine and Public Health
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    • 제35권4호
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    • pp.305-312
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    • 2002
  • Objectives : The reproductive history of women has been suggested to have a possible influence on the risk of osteoporotic fractures. The purpose of this study was to assess the association between reproductive history and hip fractures in the elderly women. Methods : The study subjects were drawn from women members of the Korean Elderly Pharmacoepidemiologic Cohort (KEPEC), aged 65 years or over, whose reproductive histories were available, and who were beneficiaries of the Korea Medical Insurance Corporation (KMIC) in 1993 and lived in Busan city, Korea. The information on reproductive histories, and possible confounders, were collected from mailed questionnaires. Potential hip fracture cases were collected from the claims data obtained between 1993 and 1998, with a hospital survey conducted to confirm the final diagnoses. Rate ratios and their 95% confidence intervals, were calculated using a Cox's proportional hazard model. Results : Following up 5,215 women for 6 years, 51 cases were confirmed with hip fractures. When adjusted for age, weight and physical activity, the rate ratio of hip fractures in women who had given birth three or more times was 0.56 (95% CI: 0.25-1.25), compared with those who had given birth two or less times. When adjusted for age, number of births, weight and physical activity, the rate ratio in women who first gave birth when younger than 22 years was 0.60 (95% CI: 0.34-1.08) compared with those who had giving birth at 22 years or older. Conclusions : According to these findings, an early age when first giving birth might decrease the risk of hip fractures in elderly Korean women.

Clinical Prognostic Score for Predicting Disease Remission with Differentiated Thyroid Cancers

  • Somboonporn, Charoonsak;Mangklabruks, Ampica;Thakkinstian, Ammarin;Vatanasapt, Patravoot;Nakaphun, Suwannee
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권6호
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    • pp.2805-2810
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    • 2016
  • Background: Differentiated thyroid cancer is the most common endocrine malignancy with a generally good prognosis. Knowing long-term outcomes of each patient helps management planning. The study was conducted to develop and validate a clinical prognostic score for predicting disease remission in patients with differentiated thyroid cancer based on patient, tumor and treatment factors. Materials and Methods: A retrospective cohort study of 1,217 differentiated thyroid cancer patients from two tertiary-care hospitals in the Northeast of Thailand was performed. Associations between potential clinical prognostic factors and remission were tested by Cox proportional-hazards analysis in 852 patients (development cohort). The prediction score was created by summation of score points weighted from regression coefficients of independent prognostic factors. Risks of disease remission were estimated and the derived score was then validated in the remaining 365 patients (validation cohort). Results: During the median follow-up time of 58 months, 648 (76.1%) patients in the development cohort had disease remission. Five independent prognostic factors were identified with corresponding score points: duration from thyroid surgery to $^{131}I$ treatment (0.721), distant metastasis at initial diagnosis (0.801), postoperative serum thyroglobulin level (0.535), anti-thyroglobulin antibodies positivity (0.546), and adequacy of serum TSH suppression (0.293). The total risk score for each patient was calculated and three categories of remission probability were proposed: ${\leq}1.628$ points (low risk, 83% remission), 1.629-1.816 points (intermediate risk, 87% remission), and ${\geq}1.817$ points (high risk, 93% remission). The concordance (C-index) was 0.761 (95% CI 0.754-0.767). Conclusions: The clinical prognostic scoring model developed to quantify the probability of disease remission can serve as a useful tool in personalized decision making regarding treatment in differentiated thyroid cancer patients.