• Title/Summary/Keyword: Cox regression model

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Corporate Governance and Long-term Corporate Survival in an Emerging Economy (신흥국 기업의 지배구조와 기업의 장기 생존)

  • Jang-Hoon Kim;Se-Yeon Ahn
    • Korea Trade Review
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    • v.46 no.3
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    • pp.65-79
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    • 2021
  • This paper investigates how corporate governance characteristics are related to long-term corporate survival in an emerging economy. We used the data of 311 companies listed on the Korean Stock Exchange (KSE) in 1979 and examined the survival chances of those companies through the IMF crisis in 1998, upon governance characteristics that are expected to increase long-term strategic orientations. We utilized Cox regression model for the analysis. The results indicate that firms with particular governance characteristics that may be tied to CEO's long-term orientations show higher long-term survivability. Specifically, the probability of a firm's long-term survival is increased when founding family ownership is sustained, the company ownership is concentrated, and the CEO is the largest shareholder. This study has significance in that it is one of initial tries to examine the impact of corporate governance on long-term corporate survival with large scale statistical analysis. Also, the study findings provide some clues as to why the portion of family firms in emerging economies is continuously increased, thus providing meaningful insights to corporate governance literature.

Prediction of Life Expectancy for Terminally Ill Cancer Patients Based on Clinical Parameters (말기 암 환자에서 임상변수를 이용한 생존 기간 예측)

  • Yeom, Chang-Hwan;Choi, Youn-Seon;Hong, Young-Seon;Park, Yong-Gyu;Lee, Hye-Ree
    • Journal of Hospice and Palliative Care
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    • v.5 no.2
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    • pp.111-124
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    • 2002
  • Purpose : Although the average life expectancy has increased due to advances in medicine, mortality due to cancer is on an increasing trend. Consequently, the number of terminally ill cancer patients is also on the rise. Predicting the survival period is an important issue in the treatment of terminally ill cancer patients since the choice of treatment would vary significantly by the patents, their families, and physicians according to the expected survival. Therefore, we investigated the prognostic factors for increased mortality risk in terminally ill cancer patients to help treat these patients by predicting the survival period. Methods : We investigated 31 clinical parameters in 157 terminally ill cancer patients admitted to in the Department of Family Medicine, National Health Insurance Corporation Ilsan Hospital between July 1, 2000 and August 31, 2001. We confirmed the patients' survival as of October 31, 2001 based on medical records and personal data. The survival rates and median survival times were estimated by the Kaplan-Meier method and Log-rank test was used to compare the differences between the survival rates according to each clinical parameter. Cox's proportional hazard model was used to determine the most predictive subset from the prognostic factors among many clinical parameters which affect the risk of death. We predicted the mean, median, the first quartile value and third quartile value of the expected lifetimes by Weibull proportional hazard regression model. Results : Out of 157 patients, 79 were male (50.3%). The mean age was $65.1{\pm}13.0$ years in males and was $64.3{\pm}13.7$ years in females. The most prevalent cancer was gastric cancer (36 patients, 22.9%), followed by lung cancer (27, 17.2%), and cervical cancer (20, 12.7%). The survival time decreased with to the following factors; mental change, anorexia, hypotension, poor performance status, leukocytosis, neutrophilia, elevated serum creatinine level, hypoalbuminemia, hyperbilirubinemia, elevated SGPT, prolonged prothrombin time (PT), prolonged activated partial thromboplastin time (aPTT), hyponatremia, and hyperkalemia. Among these factors, poor performance status, neutrophilia, prolonged PT and aPTT were significant prognostic factors of death risk in these patients according to the results of Cox's proportional hazard model. We predicted that the median life expectancy was 3.0 days when all of the above 4 factors were present, $5.7{\sim}8.2$ days when 3 of these 4 factors were present, $11.4{\sim}20.0$ days when 2 of the 4 were present, and $27.9{\sim}40.0$ when 1 of the 4 was present, and 77 days when none of these 4 factors were present. Conclusions : In terminally ill cancer patients, we found that the prognostic factors related to reduced survival time were poor performance status, neutrophilia, prolonged PT and prolonged am. The four prognostic factors enabled the prediction of life expectancy in terminally ill cancer patients.

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Effects of Obesity on Presentation of Breast Cancer, Lymph Node Metastasis and Patient Survival: A Retrospective Review

  • Kaviani, Ahmad;Neishaboury, MohamadReza;Mohammadzadeh, Narjes;Ansari-Damavandi, Maryam;Jamei, Khatereh
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2225-2229
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    • 2013
  • Background: As data on the relation between obesity and lymph node ratio are missing in the literature, we here aimed to assess the impact of obesity on this parameter and other clinicopathological features of breast cancer cases and patient survival. Materials and Methods: Medical data of 646 patients, all referred to two centers in Tehran, Iran, were reviewed. Factors that showed significant association on univariate analysis were entered in a regression model. Kaplan-Meier and Cox-regression were employed for survival analysis. Results: Obesity was correlated with the expression of estrogen and progesterone receptor (p=0.004 and p=0.039, respectively), metastasis to axillary lymph nodes (p=0.017), higher lymph node rate (p<0.001) and larger tumor size (p<0.001). The effect of obesity was stronger in premenopausal women. There was no association between obesity and expression of human epidermal growth factor receptor. Three factors showed independent association with BMI on multivariate analysis; tumor size, estrogen receptor and lymph node ratio. Obesity was predictive of shorter disease-free survival with a hazard ratio of 3.324 (95%CI: 1.225-9.017) after controlling for the above-mentioned variables. Conclusions: The findings of this study support the idea that obese women experience more advanced disease with higher axillary lymph node ratio, and therefore higher stage at the time of diagnosis. Furthermore, obesity was associated with poorer survival independent of lymph node rate.

Clinicopathologic correlation with MUC expression in advanced gastric cancer

  • Kim, Kwang;Choi, Kyeong Woon;Lee, Woo Yong
    • Korean Journal of Clinical Oncology
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    • v.14 no.2
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    • pp.89-94
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    • 2018
  • Purpose: To investigate the relationship between MUC expression and clinicopathologic factors in advanced gastric cancer. Methods: A total of 237 tumor specimens were assessed for MUC expression by immunohistochemistry. The clinicopathologic factors were investigated with MUC1, MUC2, MUC5AC, and MUC6. Results: MUC1, MUC2, MUC5AC, and MUC6 expression was identified in 148 of 237 (62.4%), 141 of 237 (59.5%), 186 of 237 (78.5%), and 146 of 237 (61.6%) specimens, respectively. MUC1 expression was correlated with age, human epidermal growth factor receptor 2 (HER2) status, lymphatic invasion, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC1expression and lymphatic invasion, diffuse type of Lauren classification. MUC5AC expression was correlated with HER2 status, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC5AC expression and HER2 status, diffuse and mixed type of Lauren classification. MUC2 and MUC6 expression were not correlated with clinicopathologic factors. The patients of MUC1 expression had poorer survival than those without MUC1 expression, but MUC2, MUC5AC or MUC6 were not related to survival. In an additional multivariate analysis that used the Cox proportional hazards model, MUC1 expression was not significantly correlated with patient survival independent of age, N-stage, and venous invasion. Conclusion: When each of these four MUCs expression is evaluated, in light of clinicopathologic factors, MUC1 expression may be considered as a prognostic factor in patients with advanced gastric cancer. Therefore, careful follow-up may be necessary because the prognosis is poor when MUC1 expression is present.

Renal function is associated with prognosis in stent-change therapy for malignant ureteral obstruction

  • Yoon, Ji Hyung;Park, Sejun;Park, Sungchan;Moon, Kyung Hyun;Cheon, Sang Hyeon;Kwon, Taekmin
    • Investigative and Clinical Urology
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    • v.59 no.6
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    • pp.376-382
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    • 2018
  • Purpose: The authors performed this study to investigate the risk factors for predicting stent failure and to evaluate its impact on prognosis. Materials and Methods: Between January 2002 and March 2017, we retrospectively reviewed 117 consecutive patients who underwent retrograde ureteral stenting and exchanging at least once every 3 months for malignant ureteral obstruction. The patients were classified according to their pre-stenting chronic kidney disease (CKD) stage. The factors affecting stent failure were analyzed using a logistic regression model. Overall survival (OS) was estimated, and the prognostic significance of each variable was estimated using Cox proportional-hazards regression modeling. Results: Before stenting, 91 patients were CKD stages 1-3 and 26 patients were CKD stages 4-5. These two groups differed significantly only in pre-stenting estimated glomerular filtration rate (eGFR), bilateral obstruction, and pre-stenting pyuria. Among the 117 patients, stent failure occurred in 30 patients (25.6%), and there were no differences between the groups. Pre-stenting pyuria and post-stenting complications were significant predictors of stent failure. There were 79 deaths in total, including 56 in the CKD stages 1-3 group and 23 in the CKD stages 4-5 group. In the multivariate analysis predicting patient OS, pre-stenting eGFR and post-stenting disease progression were significant factors. Conclusions: Internal ureteral stenting was effective for maintaining renal function in malignant ureteral obstruction. However, it did not restore renal function, which is related to the prognosis of the patients. Therefore, to improve patients' renal function and prognosis, patients who require stenting must be quickly recognized and treated.

Effects of gene-lifestyle environment interactions on type 2 diabetes mellitus development: an analysis using the Korean Genome and Epidemiology Study data (유전 요인과 생활환경 요인의 상호작용이 제2형 당뇨병 발생에 미치는 영향: 한국인유전체역학 조사사업(KoGES) 자료를 이용하여)

  • Sujin, Hyun;Sangeun, Jun
    • Journal of Korean Biological Nursing Science
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    • v.25 no.1
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    • pp.73-85
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    • 2023
  • Purpose: This study focused on identifying the interaction effects of genetic and lifestyle-environmental factors on the development of type 2 diabetes mellitus (T2D). Methods: Study subjects were selected from the Korean Genome and Epidemiology Study (KoGES) from 2001 to 2014. Data on genetic variations, anthropometric measurements, biochemical data, and seven lifestyle factors (diet, physical activity, alcohol drinking, smoking, sleep, depression, and stress) were obtained from 4,836 Koreans aged between 40 and 59 years, including those with T2D at baseline (n = 1,209), newly developed T2D (n= 1,298) and verified controls (n = 3,538). The genetic risk score (GRS) was calculated by using 11 single-nucleotide polymorphisms (SNPs) related to T2D development and the second quartile was used as the reference category. A Cox proportional hazards regression model was used to evaluate the associations of GRS and lifestyle factors with T2D risk, controlling for covariates. Results: Multivariate regression analysis revealed that GRS was the strongest risk factor for T2D, and body mass index (BMI), smoking, drinking, and spicy food preference also increased the risk. Lifestyle/environmental factors that showed significant interactions with GRS were BMI, current smoking, current drinking, fatty food preference, and spicy food preference. Conclusions: Interactions between genetic factors and lifestyle/environmental factors were associated with an increased risk of T2D. The results will be useful to provide a new perspective on genetic profiling for the earlier detection of T2D risk and clues for personalized interventions, which might be more effective prevention strategies or therapies in individuals with a genetic predisposition to T2D.

Predictive modeling algorithms for liver metastasis in colorectal cancer: A systematic review of the current literature

  • Isaac Seow-En;Ye Xin Koh;Yun Zhao;Boon Hwee Ang;Ivan En-Howe Tan;Aik Yong Chok;Emile John Kwong Wei Tan;Marianne Kit Har Au
    • Annals of Hepato-Biliary-Pancreatic Surgery
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    • v.28 no.1
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    • pp.14-24
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    • 2024
  • This study aims to assess the quality and performance of predictive models for colorectal cancer liver metastasis (CRCLM). A systematic review was performed to identify relevant studies from various databases. Studies that described or validated predictive models for CRCLM were included. The methodological quality of the predictive models was assessed. Model performance was evaluated by the reported area under the receiver operating characteristic curve (AUC). Of the 117 articles screened, seven studies comprising 14 predictive models were included. The distribution of included predictive models was as follows: radiomics (n = 3), logistic regression (n = 3), Cox regression (n = 2), nomogram (n = 3), support vector machine (SVM, n = 2), random forest (n = 2), and convolutional neural network (CNN, n = 2). Age, sex, carcinoembryonic antigen, and tumor staging (T and N stage) were the most frequently used clinicopathological predictors for CRCLM. The mean AUCs ranged from 0.697 to 0.870, with 86% of the models demonstrating clear discriminative ability (AUC > 0.70). A hybrid approach combining clinical and radiomic features with SVM provided the best performance, achieving an AUC of 0.870. The overall risk of bias was identified as high in 71% of the included studies. This review highlights the potential of predictive modeling to accurately predict the occurrence of CRCLM. Integrating clinicopathological and radiomic features with machine learning algorithms demonstrates superior predictive capabilities.

Discontinuation of antiplatelet therapy after stent-assisted coil embolization for cerebral aneurysms

  • Tae Gon Kim
    • Journal of Cerebrovascular and Endovascular Neurosurgery
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    • v.25 no.2
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    • pp.132-142
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    • 2023
  • Objective: Dual antiplatelet therapy (DAPT) is usually temporarily used after stent-assisted coil embolization (SACE), and is commonly converted to mono antiplatelet therapy (MAPT) for indefinitely. In this study, we aimed to find the possibility of discontinuing MAPT, and to determine the proper period of DAPT use. Methods: We used the Standard Sample Cohort DB dataset from the National Health Insurance Sharing Service. Among approximately 1 million people in the dataset, SACE was performed in 214 patients whose data this study analyzed. The relationship between discontinuation of antiplatelet therapy and intracranial hemorrhage or cerebral infarction was analyzed using multiple logistic regression, considering all confounding variables. The survival rate according to the continuation of antiplatelet therapy was obtained using Kaplan-Meier analysis, and the difference in survival rate according to the continuation of antiplatelet therapy was verified using the log-rank test. The hazard ratio according to continuation of antiplatelet therapy was obtained using the Cox proportional hazards model. The analysis was conducted by applying the same statistical method to the duration of DAPT use. Results: Among 214 patients who underwent SACE, 50, 159 and five patients continued, discontinued and did not use antiplatelet therapy (except at the time of procedure), respectively. In multiple logistic regression analysis, discontinuation of antiplatelet agents (including aspirin) and the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction, considering various confounding factors. In the survival analysis according to the continuation of antiplatelet agents, patients who continued to use antiplatelet agents had a higher survival rate than those in other groups (p=0.00). The survival rate was higher in the rest of the group than in the group that received DAPT for three months (p=0.00). Conclusions: Continuation of antiplatelet agents or the period of DAPT use did not affect the occurrence of intracranial hemorrhage or cerebral infarction. Considering the survival rate, it would be better to maintain at least three months of antiplatelet therapy and it might be recommended to continue DAPT use for 12 months.

The Relationship between the Cognitive Impairment and Mortality in the Rural Elderly (농촌지역 노인들의 인지기능 장애와 사망과의 관련성)

  • Sun, Byeong-Hwan;Park, Kyeong-Soo;Na, Baeg-Ju;Park, Yo-Seop;Nam, Hae-Sung;Shin, Jun-Ho;Sohn, Seok-Joon;Rhee, Jung-Ae
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.3 s.58
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    • pp.630-642
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    • 1997
  • The purpose of this study was to examine the mortality risk associated with cognitive impairment among the rural elderly. The subjective of study was 558 of 'A Study on the Depression and Cognitive Impairment in the Rural Elderly' of Jung Ae Rhee and Hyang Gyun Jung's study(1993). Cognitive impairment and other social and health factors were assessed in 558 elderly rural community residents. For this study, a Korean version of the Mini-Mental State Examination(MMSEK) was used as a global indicator of cognitive functioning. And mortality risk factors for each cognitive impairment subgroup were identified by univariate and multivariate Cox regression analysis. At baseline 22.6% of the sample were mildly impaired and 14.2% were severely impaired. As the age increased, the cognitive function was more impaired. Sexual difference was existed in the cognitive function level. Also the variables such as smoking habits, physical disorders had the significant relationship with cognitive function impairment. Across a 3-year observation period the mortality rate was 8.5% for the cognitively unimpaired, 11.1% for the mildly impaired, and 16.5% for the severly impaired respendents. And the survival probability was .92 for the cognitively unimpaired, .90 for the mildly impaired, and .86 for the severly impaired respondents. Compared to survival curve for the cognitively unimpaired group, each survival curve for the mildly and the severely impaired group was not significantly different. When adjustments models were not made for the effects of other health and social covariates, each hazard ratio of death of mildly and severely impaired persons was not significantly different as compared with the cognitively unimpaired. But, as MMSEK score increased, significantly hazard ratio of death decreased. Employing Cox univariate proportional hazards model, statistically other significant variables were age, monthly income, smoking habits, physical disorders. Also when adjustments were made for the effects of other health and social covariates, there was no difference in hazard ratio of death between those with severe or mild impairment and unimpaired persons. And as MMSEK score increased, significantly hazard ratio of death did not decrease. Employing Cox multivariate proportional hazards model, statistically other significant variables were age, monthly income, physical disorders. Employing Cox multivariate proportional hazards model by sex, at men and women statistically significant variable was only age. For both men and women, also cognitive impairment was not a significant risk factor. Other investigators have found that cognitive impairment is a significant predictor of mortality. But we didn't find that it is a significant predictor of mortality. Even though the conclusions of our study were not related to cognitive impairment and mortality, early detection of impaired cognition and attention to associated health problems could improve the quality of life of these older adults and perhaps extend their survival.

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Prognostic Factors for Overall Survival in Patients With Metastatic Colorectal Carcinoma Treated With Vascular Endothelial Growth Factor-Targeting Agents

  • Cetin, Bulent;Kaplan, Mehmet Ali;Berk, Veli;Ozturk, Selcuk Cemil;Benekli, Mustafa;Isikdogan, Abdurrahman;Ozkan, Metin;Coskun, Ugur;Buyukberber, Suleyman
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.1059-1063
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    • 2012
  • Objective: Angiogenesis represents a key element in the pathogenesis of malignancy. There are no robust data on prognostic factors for overall survival (OS) in patients with metastatic colorectal cancer treated with vascular endothelial growth factor (VEGF)-targeted therapy. The present study was conducted to establish a prognostic model for patients using an oxaliplatin-based or irinotecan-based chemotherapy plus bevacizumab in metastatic colorectal cancer. Methods: Baseline characteristics and outcomes on 170 patients treated with FOLFIRI or XELOX plus anti-VEGF therapy-naive metastatic colorectal cancer were collected from three Turkey cancer centers. Cox proportional hazards regression was used to identify independent prognostic factors for OS. Results: The median OS for the whole cohort was 19 months (95% CI, 14.3 to 23.6 months). Three of the seven adverse prognostic factors according to the Anatolian Society of Medical Oncology (ASMO) were independent predictors of short survival: serum lactate dehydrogenase (LDH) greater than the upper limit of normal (ULN; p<0.001); neutrophils greater than the ULN (p<0.0014); and progression free survival (PFS) less than 6 months (p =0.001). Conclusion: Serum LDH and neutrophil levels were the main prognostic factors in predicting survival, followed by PFS. This model validates incorporation of components of the ASMO model into patient care and clinical trials that use VEGF-targeting agents.