• Title/Summary/Keyword: Cox's proportional hazard model

Search Result 109, Processing Time 0.023 seconds

Factors Influencing on Pressure Ulcer Incidence among Older Patients with Hip Fracture in a Hospital (고관절 골절로 입원한 노인 환자의 욕창 발생 위험요인)

  • Lee, Sun Jin;Jeong, Jae Shim;Lim, Kyung-Choon;Park, Eun Young;Kim, Hye Youn
    • Journal of Korean Biological Nursing Science
    • /
    • v.21 no.1
    • /
    • pp.54-61
    • /
    • 2019
  • Purpose: This study aimed to identify the incidence and risks for pressure ulcer among older patients with hip fracture. Methods: The subject were 215 older patients suffering from hip fracture who were admitted for surgical operation from January 1, 2012 to April 30, 2016 in a university-affiliated hospital. The incidence of pressure ulcer was collected retrospectively through medical record review and the risk factors were analyzed using Cox's proportional hazard model. Results: Out of the total, 32 patients (14.9%) developed pressure ulcer with the average occurrence period being 4.72 (${\pm}3.81$) days. Stage II pressure ulcer was the most common at 72.0%. Risk factors included ambulation status before injury (p= .039), spinal anesthesia (p= .029), and stay at intensive care unit after operation (p= .009). Conclusion: Despite pressure ulcer prevention efforts, the incidence remained relatively high. Considering the identified risk factors, more efforts is needed for early detection and prevention of pressure ulcers in such patients.

Cure Rate Model with Clustered Interval Censored Data (군집화된 구간 중도절단자료에 대한 치유율 모형의 적용)

  • Kim, Yang-Jin
    • The Korean Journal of Applied Statistics
    • /
    • v.27 no.1
    • /
    • pp.21-30
    • /
    • 2014
  • Ordinary survival analysis cannot be applied when a significant fraction of patients may be cured. A cure rate model is the combination of cure fraction and survival model and can be applied to several types of cancer. In this article, the cure rate model is considered in the interval censored data with a cluster effect. A shared frailty model is introduced to characterize the cluster effect and an EM algorithm is used to estimate parameters. A simulation study is done to evaluate the performance of estimates. The proposed approach is applied to the smoking cessation study in which the event of interest is a smoking relapse. Several covariates (including intensive care) are evaluated to be effective for both the occurrence of relapse and the smoke quitting duration.

Association Between Liver Enzyme and Risk of All-Cause Mortality: Use of Korean Genome and Epidemiology Study (KoGES) Data (간 효소(AST, ALT)와 전체원인사망 위험의 관련성: 한국인유전체역학조사 자료 활용)

  • Lee, Tae-Yong;Ryu, Hyo-Sun;Park, Chang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.11
    • /
    • pp.94-103
    • /
    • 2016
  • This study was conducted to investigate the association of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with all-cause mortality among populations. The data used were from a Korean Genome and Epidemiology Study (KoGES) based on health examinations and questionnaires. The subjects consisted of 10,110 persons aged 40 and over. Hazard ratio was analyzed using Cox's proportional hazard model. The hazard ratio of AST (${\geq}50.0\;IU/L$) was 2.198 (95% CI: 1.217-3.971) after being adjusted for age, sex, education, regular exercise, smoking, drinking, WHR, and TG. In conclusion, AST was an independent significant risk factor of all-cause mortality, and ALT showed a tendency to increase. Overall, these findings indicate that AST and ALT may be useful tools for predicting mortality.

Impact of Off-Hour Hospital Presentation on Mortality in Different Subtypes of Acute Stroke in Korea : National Emergency Department Information System Data

  • Kim, Taikwan;Jwa, Cheolsu
    • Journal of Korean Neurosurgical Society
    • /
    • v.64 no.1
    • /
    • pp.51-59
    • /
    • 2021
  • Objective : Several studies have reported inconsistent findings among countries on whether off-hour hospital presentation is associated with worse outcome in patients with acute stroke. However, its association is yet not clear and has not been thoroughly studied in Korea. We assessed nationwide administrative data to verify off-hour effect in different subtypes of acute stroke in Korea. Methods : We respectively analyzed the nationwide administrative data of National Emergency Department Information System in Korea; 7144 of ischemic stroke (IS), 2424 of intracerebral hemorrhage (ICH), and 1482 of subarachnoid hemorrhage (SAH), respectively. "Off-hour hospital presentation" was defined as weekends, holidays, and any times except 8:00 AM to 6:00 PM on weekdays. The primary outcome measure was in-hospital mortality in different subtypes of acute stroke. We adjusted for covariates to influence the primary outcome using binary logistic regression model and Cox's proportional hazard model. Results : In subjects with IS, off-hour hospital presentation was associated with unfavorable outcome (24.6% off hours vs. 20.9% working hours, p<0.001) and in-hospital mortality (5.3% off hours vs. 3.9% working hours, p=0.004), even after adjustment for compounding variables (hazard ratio [HR], 1.244; 95% confidence interval [CI], 1.106-1.400; HR, 1.402; 95% CI, 1.124-1.747, respectively). Off-hours had significantly more elderly ≥65 years (35.4% off hours vs. 32.1% working hours, p=0.029) and significantly more frequent intensive care unit admission (32.5% off hours vs. 29.9% working hours, p=0.017) than working hours. However, off-hour hospital presentation was not related to poor short-term outcome in subjects with ICH and SAH. Conclusion : This study indicates that off-hour hospital presentation may lead to poor short-term morbidity and mortality in patients with IS, but not in patients with ICH and SAH in Korea. Excessive death seems to be ascribed to old age or the higher severity of medical conditions apart from that of stroke during off hours.

Factors Affecting Breastfeeding Rate and Duration (모유수유 실천 및 수유기간에 영향을 미치는 요인)

  • Hwang, Won-Ju;Kang, Dae-Ryong;Suh, Moon-Hee;Chung, Woo-Jin
    • Journal of Preventive Medicine and Public Health
    • /
    • v.39 no.1
    • /
    • pp.74-80
    • /
    • 2006
  • Objectives: The purpose of this study is to examine the factors affecting the rate and duration of breastfeeding. Methods: We analyzed the data from the year 2000 Korea National Fertility Survey that was collected through direct interviews. In particular, the mothers who delivered their last child and the child was under 1 year of age from January 1998 to June 2000 (N=1,066) were analyzed via a logistic model to assess the factors affecting the breastfeeding rate. Among the study subjects, those who had initiated breastfeeding (N=740) were analyzed through Cox's proportional hazard model to evaluate the factors affecting the duration of breastfeeding. Results: The multivariate logistic model showed that the delivery type and the baby's birth-weight have a statistically significant influence on the breastfeeding rate. Women who delivered their babies through Cesarean section were less likely than others to breastfeed. In contrast, the women whose babies weighed 2.5Kg or more were more likely than others to breastfeed. The results obtained from the survival analysis are as follows: the higher the mother's education level, the shorter is the breastfeeding duration. The mother's work status played a significant role in the early termination of breastfeeding. Women aged 35 or older showed a longer breastfeeding duration than the younger age groups, whereas the maternal age was not a significant factor in affecting whether or not a mother would breastfeed. Conclusions: Reducing the cases of operative delivery (Cesarean section) and low weight births, enlightening young and highly educated women on breastfeeding and improving the environment for breastfeeding on the job are important strategies to encourage women to breastfeed.

Factors Affecting Survival Time of Cholangiocarcinoma Patients: A Prospective Study in Northeast Thailand

  • Woradet, Somkiattiyos;Promthet, Supannee;Songserm, Nopparat;Parkin, Donald Maxwell
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.3
    • /
    • pp.1623-1627
    • /
    • 2013
  • Cholangiocarcinoma (CCA) is a major health problem and cause of death among people in Northeastern Thailand. In this prospective study 171 patients newly diagnosed with CCA by physicians in 5 tertiary hospitals in four provinces of northeastern of Thailand between February and July 2011 were followed up to January 2012. The outcome was survival time from diagnosis to death. A total of 758.4 person-months of follow-up were available. The mortality rate was 16.9 per 100 person-months (95%CI: 14.1-20.1). The median survival time among CCA patients was 4.3 months (95%CI: 3.3-5.1). Cox's proportional hazard model was used to study the independent effects of factors affecting survival time among patients. Statistically significant factors included advanced stage at diagnosis (HR: 2.5, 95%CI: 1.7-3.8), presentation with jaundice (HR: 1.7, 95%CI: 1.1-2.4) or ascites (HR: 2.8, 95%CI: 1.8-4.4), and positive serum carcinoembryonic antigen (HR: 2.3, 95%CI: 1.2-4.3). Patients who had received standard treatment had a better prognosis that those who did not (HR: 0.5, 95%CI: 0.3-0.7).

Low Income and Rural County of Residence Increase Mortality from Bone and Joint Sarcomas

  • Cheung, Min Rex
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.9
    • /
    • pp.5043-5047
    • /
    • 2013
  • Background: This is a part of a larger effort to characterize the effects on socio-economic factors (SEFs) on cancer outcome. Surveillance, Epidemiology and End Result (SEER) bone and joint sarcoma (BJS) data were used to identify potential disparities in cause specific survival (CSS). Materials and Methods: This study analyzed SEFs in conjunction with biologic and treatment factors. Absolute BJS specific risks were calculated and the areas under the receiver operating characteristic (ROC) curve were computed for predictors. Actuarial survival analysis was performed with Kaplan-Meier method. Kolmogorov-Smirnov's 2-sample test was used to for comparing two survival curves. Cox proportional hazard model was used for multivariate analysis. Results: There were 13501 patients diagnosed BJS from 1973 to 2009. The mean follow up time (SD) was 75.6 (90.1) months. Staging was the highest predictive factor of outcome (ROC area of 0.68). SEER stage, histology, primary site and sex were highly significant pre-treatment predictors of CSS. Under multivariate analysis, patients living in low income neighborhoods and rural areas had a 2% and 5% disadvantage in cause specific survival respectively. Conclusions: This study has found 2-5% decrement of CSS of BJS due to SEFs. These data may be used to generate testable hypothesis for future clinical trials to eliminate BJS outcome disparities.

Risk Factors Related to Development of Delirium in Hospice Patients (호스피스 병동의 암환자에서 섬망 발생 위험 요인)

  • Ko, Hae Jin;Youn, Chang Ho;Chung, Seung Eun;Kim, A Sol;Kim, Hyo Min
    • Journal of Hospice and Palliative Care
    • /
    • v.17 no.3
    • /
    • pp.170-178
    • /
    • 2014
  • Purpose: Delirium is a common and serious neuropsychiatric complication among terminally ill cancer patients. We investigated risk factors related to the development of delirium among hospice care patients. Methods: Between May 2011 and September 2012, we included patients who were mentally alert and had no psychiatric disease or drug addiction at the hospice ward of two local hospitals. Among them, participants who had been diagnosed with delirium by two doctors according to the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-4th edition) criteria were grouped as Delirium Group. We analyzed results of psychometric and other laboratory tests performed at the time of patient's admission - psychometric tests included cognitive function (mini-mental status examination, MMSE), depression (Beck Depression Inventory, BDI), anxiety, and insomnia (Insomnia Severity Index, ISI). Logistic regression analysis was used to compare delirium and the related factors. Cox's proportional hazard model was performed using significant factors of logistic regression analysis. Results: Of the 96 patients who met the inclusion criteria, 41 (42.7%) developed delirium. According to the logistic regression analysis, primary cancer site, cognitive impairment (MMSE < 24), depression ($BDI{\geq}16$), and insomnia ($ISI{\geq}15$) were significant factors related to delirium. Among the four factors, depression (OR 5.130; 95% CI, 2.009~13.097) and cognitive impairment (OR 5.130; 95% CI, 2.009~13.097) were found significant using Cox's proportional hazard model. Conclusion: The development of delirium was significantly related to depression and cognitive impairment among patients receiving hospice care. It is necessary to carefully monitor depression and cognitive function in hospice care.

A Study on the Effects of Livestock Disease News on the Purchase of Beef and Pork (축산 질병 보도가 소, 돼지고기 구입에 미치는 영향에 관한 연구)

  • Shin, Jeong-Seop
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.10
    • /
    • pp.425-432
    • /
    • 2019
  • This study examined the effects of livestock disease news, such as foot-and-mouth disease (FMD), collected by the Korea Press Foundation on BIGKinds on the consumption of beef and pork. The consumer purchase data were obtained from the Rural Development Administration's Agrifood consumer panel data. Survival analysis showed that the FMD news noted beef and pork, and the first purchase rate decreased due to FMD news. The time-dependent Cox proportional hazards model revealed all models to be significant. FMD news was significant in each model. In 2010, the Hazard Ratio of domestic and imported pork was 0.999, and the first purchase rate decreased 0.999 times for each additional FMD news item. On the other hand, the Hazard Ratio of pork in 2015 was 1.001, and the first purchase rate increased. In the case of beef, results similar to pork were shown. This study estimated the impact of consumer meat consumption disease news on the first purchases according to origin and meat. These results provide the necessary information for rational production and consumption activities. In addition, it can also be used for promotion by estimating the duration of livestock disease news.

Application of Cox and Parametric Survival Models to Assess Social Determinants of Health Affecting Three-Year Survival of Breast Cancer Patients

  • Mohseny, Maryam;Amanpour, Farzaneh;Mosavi-Jarrahi, Alireza;Jafari, Hossein;Moradi-Joo, Mohammad;Monfared, Esmat Davoudi
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.sup3
    • /
    • pp.311-316
    • /
    • 2016
  • Breast cancer is one of the most common causes of cancer mortality in Iran. Social determinants of health are among the key factors affecting the pathogenesis of diseases. This cross-sectional study aimed to determine the social determinants of breast cancer survival time with parametric and semi-parametric regression models. It was conducted on male and female patients diagnosed with breast cancer presenting to the Cancer Research Center of Shohada-E-Tajrish Hospital from 2006 to 2010. The Cox proportional hazard model and parametric models including the Weibull, log normal and log-logistic models were applied to determine the social determinants of survival time of breast cancer patients. The Akaike information criterion (AIC) was used to assess the best fit. Statistical analysis was performed with STATA (version 11) software. This study was performed on 797 breast cancer patients, aged 25-93 years with a mean age of 54.7 (${\pm}11.9$) years. In both semi-parametric and parametric models, the three-year survival was related to level of education and municipal district of residence (P<0.05). The AIC suggested that log normal distribution was the best fit for the three-year survival time of breast cancer patients. Social determinants of health such as level of education and municipal district of residence affect the survival of breast cancer cases. Future studies must focus on the effect of childhood social class on the survival times of cancers, which have hitherto only been paid limited attention.