scholarly journals PENAKSIRAN PARAMETER ANALISIS REGRESI COX DAN ANALISIS SURVIVAL BAYESIAN

2019 ◽  
Vol 1 (2) ◽  
pp. 16-26
Author(s):  
Rina Wijayanti
Keyword(s):  
Parameter Estimation ◽  
Statistical Approach ◽  
Cox Regression ◽  
Partial Likelihood ◽  
Parameter Estimates ◽  
Cox Regression Analysis ◽  
New Information ◽  
Classical Statistics ◽  
Model Complex ◽  
Close Form

In the theory of estimation, there are two approaches, namely the classical statistical approach and global statistical approach (Bayesian). Classical statistics are statistics in which the procedure is the decision based only on the data samples taken from the population. While Bayesian statistics in making decisions based on new information from the observed data (sample) and prior knowledge. At this writing Cox Regression Analysis will be taken as an example of parameter estimation by the classical statistical approach Survival Analysis and Bayesian statistical approach as an example of global (Bayesian). Survival Bayesial parameter estimation using MCMC algorithms for model complex / complicated and difficult to resolve while the Cox regression models using the method of partial likelihood. Results of the parameter estimates do not close form that needs to be done by the method of Newton-Raphson iteration.

scholarly journals High-Dimensional Cox Regression Analysis in Genetic Studies with Censored Survival Outcomes

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Jinfeng Xu
Keyword(s):  
Relative Risk ◽  
Variable Selection ◽  
Cox Regression ◽  
Cox Model ◽  
Partial Likelihood ◽  
Likelihood Method ◽  
Dimensional Case ◽  
High Dimensional ◽  
Cox Regression Analysis ◽  
Penalization Methods

With the advancement of high-throughput technologies, nowadays high-dimensional genomic and proteomic data are easy to obtain and have become ever increasingly important in unveiling the complex etiology of many diseases. While relating a large number of factors to a survival outcome through the Cox relative risk model, various techniques have been proposed in the literature. We review some recently developed methods for such analysis. For high-dimensional variable selection in the Cox model with parametric relative risk, we consider the univariate shrinkage method (US) using the lasso penalty and the penalized partial likelihood method using the folded penalties (PPL). The penalization methods are not restricted to the finite-dimensional case. For the high-dimensional (p→∞,p≪n) or ultrahigh-dimensional case (n→∞,n≪p), both the sure independence screening (SIS) method and the extended Bayesian information criterion (EBIC) can be further incorporated into the penalization methods for variable selection. We also consider the penalization method for the Cox model with semiparametric relative risk, and the modified partial least squares method for the Cox model. The comparison of different methods is discussed and numerical examples are provided for the illustration. Finally, areas of further research are presented.

Predictive Model for Live Birth at 12 Months After Starting In-Vitro Fertilization Treatment

MedPharmRes ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 5-20
Author(s):  
Vu Ho ◽  
Toan Pham ◽  
Tuong Ho ◽  
Lan Vuong
Keyword(s):  
In Vitro Fertilization ◽  
Live Birth ◽  
Cox Regression ◽  
Financial Burden ◽  
Oocyte Retrieval ◽  
Operating Characteristics ◽  
Vitro Fertilization ◽  
Cox Regression Analysis ◽  
Significant Difference

IVF carries a considerable physical, emotional and financial burden. Therefore, it would be useful to be able to predict the likelihood of success for each couple. The aim of this retrospective cohort study was to develop a prediction model to estimate the probability of a live birth at 12 months after one completed IVF cycle (all fresh and frozen embryo transfers from the same oocyte retrieval). We analyzed data collected from 2600 women undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) at a single center in Vietnam between April 2014 and December 2015. All patients received gonadotropin-releasing hormone (GnRH) antagonist stimulation, followed by fresh and/or frozen embryo transfer (FET) on Day 3. Using Cox regression analysis, five predictive factors were identified: female age, total dose of recombinant follicle stimulating hormone used, type of trigger, fresh or FET during the first transfer, and number of subsequent FET after the first transfer. The area under the receiver operating characteristics curve for the final model was 0.63 (95% confidence interval [CI] 0.60‒0.65) and 0.60 (95% CI 0.57‒0.63) for the validation cohort. There was no significant difference between the predicted and observed probabilities of live birth (Hosmer-Lemeshow test, p > 0.05). The model developed had similar discrimination to existing models and could be implemented in clinical practice.

Does Hospitalization Predict the Disease Course in Ulcerative Colitis? Prevalence and Predictors of Hospitalization and Re- Hospitalization in Ulcerative Colitis in a Population-based Inception Cohort (2000-2012)

2015 ◽  
Vol 24 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Petra A. Golovics ◽  
Laszlo Lakatos ◽  
Michael D. Mandel ◽  
Barbara D. Lovasz ◽  
Zsuzsanna Vegh ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Cox Regression ◽  
Diagnostic Procedures ◽  
Population Based ◽  
Disease Course ◽  
Inception Cohort ◽  
Disease Extent ◽  
Cox Regression Analysis ◽  
Hospitalization Rates

Background & Aims: Limited data are available on the hospitalization rates in population-based studies. Since this is a very important outcome measure, the aim of this study was to analyze prospectively if early hospitalization is associated with the later disease course as well as to determine the prevalence and predictors of hospitalization and re-hospitalization in the population-based ulcerative colitis (UC) inception cohort in the Veszprem province database between 2000 and 2012. Methods: Data of 347 incident UC patients diagnosed between January 1, 2000 and December 31, 2010 were analyzed (M/F: 200/147, median age at diagnosis: 36, IQR: 26-50 years, follow-up duration: 7, IQR 4-10 years). Both in- and outpatient records were collected and comprehensively reviewed. Results: Probabilities of first UC-related hospitalization were 28.6%, 53.7% and 66.2% and of first re-hospitalization were 23.7%, 55.8% and 74.6% after 1-, 5- and 10- years of follow-up, respectively. Main UC-related causes for first hospitalization were diagnostic procedures (26.7%), disease activity (22.4%) or UC-related surgery (4.8%), but a significant percentage was unrelated to IBD (44.8%). In Kaplan-Meier and Cox-regression analysis disease extent at diagnosis (HR extensive: 1.79, p=0.02) or at last follow-up (HR: 1.56, p=0.001), need for steroids (HR: 1.98, p<0.001), azathioprine (HR: 1.55, p=0.038) and anti-TNF (HR: 2.28, p<0.001) were associated with the risk of UC-related hospitalization. Early hospitalization was not associated with a specific disease phenotype or outcome; however, 46.2% of all colectomies were performed in the year of diagnosis. Conclusion: Hospitalization and re-hospitalization rates were relatively high in this population-based UC cohort. Early hospitalization was not predictive for the later disease course.

Red Blood Cell Indices in Relation to Post-stroke Psychiatric Disorders: A Longitudinal Study in a Follow-up Stroke Clinic

2020 ◽  
Vol 17 (3) ◽  
pp. 218-223
Author(s):  
Haichao Wang ◽  
Li Gong ◽  
Xiaomei Xia ◽  
Qiong Dong ◽  
Aiping Jin ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Ischemic Stroke ◽  
Blood Cell ◽  
Cox Regression ◽  
Depression And Anxiety ◽  
Cox Regression Analysis ◽  
Post Stroke ◽  
Rbc Indices ◽  
Post Stroke Depression

Background: Depression and anxiety after stroke are common conditions that are likely to be neglected. Abnormal red blood cell (RBC) indices may be associated with neuropsychiatric disorders. However, the association of RBC indices with post-stroke depression (PSD) and poststroke anxiety (PSA) has not been sufficiently investigated. Methods: We aimed to investigate the trajectory of post-stroke depression and anxiety in our follow- up stroke clinic at 1, 3, and 6 months, and the association of RBC indices with these. One hundred and sixty-two patients with a new diagnosis of ischemic stroke were followed up at 1, 3, and 6 months, and underwent Patient Health Questionnaire-9 (PHQ-9) and the general anxiety disorder 7-item (GAD-7) questionnaire for evaluation of depression and anxiety, respectively. First, we used Kaplan-Meier analysis to investigate the accumulated incidences of post-stroke depression and post-stroke anxiety. Next, to explore the association of RBC indices with psychiatric disorders after an ischemic stroke attack, we adjusted for demographic and vascular risk factors using multivariate Cox regression analysis. Results: Of the 162 patients with new-onset of ischemic stroke, we found the accumulated incidence rates of PSD (1.2%, 17.9%, and 35.8%) and PSA (1.2%, 13.6%, and 15.4%) at 1, 3, and 6 months, respectively. The incident PSD and PSA increased 3 months after a stroke attack. Multivariate Cox regression analysis indicated independent positive associations between PSD risk and higher mean corpuscular volume (MCV) (OR=1.42, 95% CI=1.16-1.76), older age (OR=2.63, 95% CI=1.16-5.93), and a negative relationship between male sex (OR=0.95, 95% CI=0.91-0.99) and PSA. Conclusion: The risks of PSD and PSA increased substantially 3 months beyond stroke onset. Of the RBC indices, higher MCV, showed an independent positive association with PSD.

Prognostic role of aberrant mTOR activation in patients with stage II and III colorectal cancer

2020 ◽  
Vol 14 (12) ◽  
pp. 1127-1137
Author(s):  
Tong-Tong Zhang ◽  
Yi-Qing Zhu ◽  
Hong-Qing Cai ◽  
Jun-Wen Zheng ◽  
Jia-Jie Hao ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cox Regression ◽  
Disease Free Survival ◽  
Stage Ii ◽  
Poor Prognostic Factor ◽  
Cox Regression Analysis ◽  
Kaplan Meier ◽  
Potential Biomarker ◽  
Risk Predictor

Aim: This study aimed to develop an effective risk predictor for patients with stage II and III colorectal cancer (CRC). Materials & methods: The prognostic value of p-mTOR (Ser2448) levels was analyzed using Kaplan–Meier survival analysis and Cox regression analysis. Results: The levels of p-mTOR were increased in CRC specimens and significantly correlated with poor prognosis in patients with stage II and III CRC. Notably, the p-mTOR level was an independent poor prognostic factor for disease-free survival and overall survival in stage II CRC. Conclusion: Aberrant mTOR activation was significantly associated with the risk of recurrence or death in patients with stage II and III CRC, thus this activated proteins that may serve as a potential biomarker for high-risk CRC.

scholarly journals P-Cresyl Sulfate Is a Valuable Predictor of Clinical Outcomes in Pre-ESRD Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Cheng-Jui Lin ◽  
Chi-Feng Pan ◽  
Chih-Kuang Chuang ◽  
Fang-Ju Sun ◽  
Duen-Jen Wang ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Cardiovascular Event ◽  
Cox Regression ◽  
Medical Center ◽  
Serum Biochemistry ◽  
Cox Regression Analysis ◽  
Kaplan Meier ◽  
Valuable Marker ◽  
Valuable Predictor

Background/Aims. Previous studies have reported p-cresyl sulfate (PCS) was related to endothelial dysfunction and adverse clinical effect. We investigate the adverse effects of PCS on clinical outcomes in a chronic kidney disease (CKD) cohort study.Methods. 72 predialysis patients were enrolled from a single medical center. Serum biochemistry data and PCS were measured. The clinical outcomes including cardiovascular event, all-cause mortality, and dialysis event were recorded during a 3-year follow-up.Results. After adjusting other independent variables, multivariate Cox regression analysis showed age (HR: 1.12,P=0.01), cardiovascular disease history (HR: 6.28,P=0.02), and PCS (HR: 1.12,P=0.02) were independently associated with cardiovascular event; age (HR: 0.91,P<0.01), serum albumin (HR: 0.03,P<0.01), and PCS level (HR: 1.17,P<0.01) reached significant correlation with dialysis event. Kaplan-Meier analysis revealed that patients with higher serum p-cresyl sulfate (>6 mg/L) were significantly associated with cardiovascular and dialysis event (log rankP=0.03, log rankP<0.01, resp.).Conclusion. Our study shows serum PCS could be a valuable marker in predicting cardiovascular event and renal function progression in CKD patients without dialysis.

Predicting long-term cardiovascular outcomes of patients with acute myocardial infarction using soluble ST2

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mustafa Umut Somuncu ◽  
Belma Kalayci ◽  
Ahmet Avci ◽  
Tunahan Akgun ◽  
Huseyin Karakurt ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Cox Regression ◽  
High Serum ◽  
Major Adverse Cardiovascular Events ◽  
Lower Systolic Blood Pressure ◽  
Cox Regression Analysis ◽  
Killip Class ◽  
Target Vessel Revascularization

AbstractBackgroundThe increase in soluble suppression of tumorigenicity 2 (sST2) both in the diagnosis and prognosis of heart failure is well established; however, existing data regarding sST2 values as the prognostic marker after myocardial infarction (MI) are limited and have been conflicting. This study aimed to assess the clinical significance of sST2 in predicting 1-year adverse cardiovascular (CV) events in MI patients.Materials and methodsIn this prospective study, 380 MI patients were included. Participants were grouped into low sST2 (n = 264, mean age: 60.0 ± 12.1 years) and high sST2 groups (n = 116, mean age: 60.5 ± 11.6 years), and all study populations were followed up for major adverse cardiovascular events (MACE) which are composed of CV mortality, target vessel revascularization (TVR), non-fatal reinfarction, stroke and heart failure.ResultsDuring a 12-month follow-up, 68 (17.8%) patients had MACE. CV mortality and heart failure were significantly higher in the high sST2 group compared to the low sST2 group (15.5% vs. 4.9%, p = 0.001 and 8.6% vs. 3.4% p = 0.032, respectively). Multivariate Cox regression analysis concluded that high serum sST2 independently predicted 1-year CV mortality [hazard ratio (HR) 2.263, 95% confidence interval (CI) 1.124–4.557, p = 0.022)]. Besides, older age, Killip class >1, left anterior descending (LAD) as the culprit artery and lower systolic blood pressure were the other independent risk factors for 1-year CV mortality.ConclusionsHigh sST2 levels are an important predictor of MACE, including CV mortality and heart failure in a 1-year follow-up period in MI patients.

scholarly journals Propensity score‐matched comparison of stenting as a bridge to surgery and emergency surgery for acute malignant left‐sided colonic obstruction

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuepeng Cao ◽  
Qing Chen ◽  
Zhizhan Ni ◽  
Feng Wu ◽  
Chenshen Huang ◽  
...  
Keyword(s):  
Overall Survival ◽  
Propensity Score ◽  
Emergency Surgery ◽  
Perineural Invasion ◽  
Cox Regression ◽  
Colonic Obstruction ◽  
Metal Stents ◽  
Bridge To Surgery ◽  
Cox Regression Analysis ◽  
Self Expanding Metal Stents

Abstract Background Bridge to elective surgery (BTS) using self-expanding metal stents (SEMSs) is a common alternative to emergency surgery (ES) for acute malignant left-sided colonic obstruction (AMLCO). However, studies regarding the long-term impact of BTS are limited and have reported unclear results. Methods A multicenter observational study was performed at three hospitals from April 2012 to December 2019. Propensity score matching (PSM) was introduced to minimize selection bias. The primary endpoint was overall survival. The secondary endpoints included surgical approaches, primary resection types, total stent-related adverse effects (AEs), surgical AEs, length of hospital stay, 30-day mortality and tumor recurrence. Results Forty-nine patients in both the BTS and ES groups were matched. Patients in the BTS group more often underwent laparoscopic resection [31 (63.3%) vs. 8 (16.3%), p < 0.001], were less likely to have a primary stoma [13 (26.5%) vs. 26 (53.1%), p = 0.007] and more often had perineural invasion [25 (51.0 %) vs. 13 (26.5 %), p = 0.013]. The median overall survival was significantly lower in patients with stent insertion (41 vs. 65 months, p = 0.041). The 3-year overall survival (53.0 vs. 77.2%, p = 0.039) and 5-year overall survival (30.6 vs. 55.0%, p = 0.025) were significantly less favorable in the BTS group. In multivariate Cox regression analysis, stenting (hazard ratio(HR) = 2.309(1.052–5.066), p = 0.037), surgical AEs (HR = 1.394 (1.053–1.845), p = 0.020) and pTNM stage (HR = 1.706 (1.116–2.607), p = 0.014) were positively correlated with overall survival in matched patients. Conclusions Self-expanding metal stents as “a bridge to surgery” are associated with more perineural invasion, a higher recurrence rate and worse overall survival in patients with acute malignant left-sided colonic obstruction compared with emergency surgery.

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