Simultaneous non-parametric confidence intervals for survival probabilities from censored data

In medical studies with censored data Kaplan and Meier's product limit estimator has frequent use as the estimate of the survival function. Simultaneous confidence intervals for the survival function at various time points constitute a useful addition to the analysis. This study compares several such methods. We consider in a simulation investigation two whole curve confidence bands and four methods based on the Bonferroni inequality. The results show that three Bonferroni-type methods are essentially equivalent, all being better than the other methods when the number of time points is small (3 or 5).     

Real-world cost-effectiveness of drug-eluting stents vs. bare-metal stents for coronary heart disease—A five-year follow-up study

Objective

To evaluate the cost-effectiveness of using drugeluting stents (DES) compared to bare-metal stents (BMS) for coronary heart disease (CHD).

Long-Term Outcomes of Complete Revascularization With Percutaneous Coronary Intervention in Acute Coronary Syndromes

ObjectivesThe aim of this study was to evaluate the long-term outcomes of patients with acute coronary syndromes (ACS) with multivessel disease undergoing percutaneous coronary intervention (PCI).BackgroundControversy exists regarding the benefit of multivessel PCI across the spectrum of ACS.MethodsA total of 9,094 patients with ACS and multivessel disease (≥70% stenosis in 2 or more major epicardial vessels) undergoing PCI from the Alberta COAPT (Contemporary Acute Coronary Syndrome Patients Invasive Treatment Strategies) registry (April 1, 2007, to March 31, 2013) were reviewed. Comparisons were made between patients who underwent complete revascularization and those with incomplete revascularization. Complete revascularization was defined as multivessel PCI with a residual angiographic jeopardy score ≤10%. Associations between revascularization status and all-cause death or new myocardial infarction (primary composite endpoint) and all-cause death, new myocardial infarction, or repeat revascularization (secondary composite endpoint) were evaluated.ResultsOf the study cohort, 66.0% underwent complete revascularization. Compared with incomplete revascularization, the primary composite endpoint occurred less frequently with complete revascularization (event rate within 5 years 15.4% vs. 22.2%; inverse probability-weighted hazard ratio [IPW-HR]: 0.78; 95% confidence interval [CI]: 0.73 to 0.84; p < 0.0001). The secondary composite endpoint was less likely to occur with complete revascularization (event rate within 5 years 23.3% vs. 37.5%; IPW-HR: 0.61; 95% CI: 0.58 to 0.65; p < 0.0001). Complete revascularization was associated with a reduction in all-cause death (IPW-HR: 0.79; 95% CI: 0.73 to 0.86; p = 0.0004), new myocardial infarction (IPW-HR: 0.76; 95% CI: 0.69 to 0.84; p < 0.0001), and repeat revascularization (IPW-HR: 0.53; 95% CI: 0.49 to 0.57; p < 0.0001).ConclusionsResults from this large contemporary registry of patients with ACS and PCI for multivessel disease suggest that complete revascularization occurs commonly and is associated with improved clinical outcomes (including survival) within 5 years.     

The PARTNER 3 Bicuspid Registry for Transcatheter Aortic Valve Replacement in Low-Surgical-Risk Patients

ObjectivesThe study compared 1-year outcomes between transcatheter aortic valve replacement (TAVR) patients with bicuspid aortic valve (BAV) morphology and clinically similar patients having tricuspid aortic valve (TAV) morphology.BackgroundThere are limited prospective data on TAVR using the SAPIEN 3 device in low-surgical-risk patients with severe, symptomatic aortic stenosis and bicuspid anatomy.MethodsLow-risk, severe aortic stenosis patients with BAV were candidates for the PARTNER 3 (Placement of Aortic Transcatheter Valves 3) (P3) bicuspid registry or the P3 bicuspid continued access protocol. Patients treated in these registries were pooled and propensity score matched to TAV patients from the P3 randomized TAVR trial. Outcomes were compared between groups. The primary endpoint was the 1-year composite rate of death, stroke, and cardiovascular rehospitalization.ResultsOf 320 total submitted BAV patients, 169 (53%) were treated, and most were Sievers type 1. The remaining 151 patients were excluded caused by anatomic or clinical criteria. Propensity score matching with the P3 TAVR cohort (496 patients) yielded 148 pairs. There were no differences in baseline clinical characteristics; however, BAV patients had larger annuli and they experienced longer procedure duration. There was no difference in the primary endpoint between BAV and TAV (10.9% vs 10.2%; P = 0.80) or in the rates of the individual components (death: 0.7% vs 1.4%; P = 0.58; stroke: 2.1% vs 2.0%; P = 0.99; cardiovascular rehospitalization: 9.6% vs 9.5%; P = 0.96).ConclusionsAmong highly select bicuspid aortic stenosis low-surgical-risk patients without extensive raphe or subannular calcification, TAVR with the SAPIEN 3 valve demonstrated similar outcomes to a matched cohort of patients with tricuspid aortic stenosis.     

Minimum 10 Year Survivorship Analysis of a Partially Coated Hydroxyapatite Tapered Femoral Stem in Elderly Patients With an Average Age Over 75

This is a retrospective, non-comparative study of 212 consecutive patients who underwent Total Hip Arthroplasty with an uncemented hydroxyapatite (HA) coated stem system from November 1997 to March 2000. The objective of the study was to analyze the performance of the implant at a minimum of 10 years in older patients (mean age 79.6 years). The Kaplan-Meier survivorship of the femoral stem at 10 years was 100%, and 97.5% for the whole prosthesis. The mean Merle d'Aubigné clinical score improved from 4.4 ± 2.1 points pre-operatively to 13.39 ± 3.77 points at final follow-up (p < 0.05), and the mean VAS score for thigh pain was 1.25. The radiographic analysis showed that there were no significant radiolucent lines or osteolysis compromising the fixation of the implant.     

Long-Term Seizure Outcome following Resective Surgery for Epilepsy: To Be or Not to Be Completely Cured?

Surgical intervention is expected to improve the quality of life in patients with intractable epilepsy by providing adequate seizure control. Although many previous studies showed various rates of seizure freedom, definite conclusions have not yet been made regarding outcomes. In order to clarify the long-term postoperative outcome for a period up to 10 years, a retrospective review of our patients was performed longitudinally by using the survival analysis method. The postoperative state of epilepsy in 76 patients who underwent resection surgery was assessed based on Engel’s criteria. In addition, Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom. In this patient group, abnormal lesion were detected by MRI in 70 out of 76 cases, and the ictal onset zone was finally identified within temporal lobe in 51 cases. The most favorable outcome, defined as Engel Class Ia, was observed in 26 (37%), 24 (40%), and 18 (41%) cases at 2, 5, and 10 years after surgery, respectively. The Kaplan-Meier survival curve in the overall group estimated the probability of seizure freedom as 75% (95% confidence interval [CI] 70–80%), 67% (62–72%), and 51% (45–57%) at 2, 5, and 10 years follow up, respectively. Half of all seizure recurrences occurred within the first 2 postoperative years. In this study, we showed that long-term favorable outcome of seizure control following resection surgery can be achieved in more than half of the patients.     

Statistical Methods for Conditional Survival Analysis

We investigate the survival distribution of the patients who have survived over a certain time period. This is called a conditional survival distribution. In this paper, we show that one-sample estimation, two-sample comparison and regression analysis of conditional survival distributions can be conducted using the regular methods for unconditional survival distributions that are provided by the standard statistical software, such as SAS and SPSS. We conduct extensive simulations to evaluate the finite sample property of these conditional survival analysis methods. We illustrate these methods with real clinical data.     

The prognostic value of the lysyl oxidase family in ovarian cancer

BackgroundOur study intended to evaluate the prognostic value of lysyl oxidase (LOX) and its four relevant members, the lysyl oxidase–like genes (LOXL1‐4), in ovarian cancer (OC) patients.Material and MethodsThe Kaplan‐Meier plotter (KM plotter) database was used to investigate the prognostic power of the LOX family for OC patients. Overall survival (OS) and progression‐free survival (PFS) were the clinical endpoints. The prognostic roles of the LOX family in OC patients were also analyzed according to various clinicopathological characteristics, including histological subtypes, clinical stages, pathological grades, and chemotherapeutic treatments.ResultsOverexpression of LOX, LOXL1, LOXL2, and LOXL3 mRNA indicated poor OS and PFS in OC patients, particularly in serous and grade II + III OC patients. Overexpression of LOXL4 mRNA resulted in worse PFS in OC patients. Overexpression of LOX and LOXL1 mRNA showed worse OS and PFS in stage III + IV OC patients, and overexpression of LOXL3 mRNA indicated worse OS and PFS in stage I + II OC patients. Overexpression of LOX, LOXL3, and LOXL4 mRNA indicated worse OS and PFS among OC patients who received platinum, taxol, and taxol + platinum chemotherapy. Overexpression of LOXL1 and LOXL2 mRNA was related to lower OS and PFS in OC patients who received platinum chemotherapy.ConclusionLOX, LOXL1, LOXL2, and LOXL3 may become potential predictive markers for negative outcomes in OC patients. Moreover, the LOX family can serve as new molecular predictors for the efficiency of platinum‐based chemotherapy in OC patients.     

基于Oncomine数据库分析SNRPB基因在乳腺癌中的表达及临床意义

目的:研究小核糖体核蛋白B（small nuclear ribonucleoprotein polypeptides B and B1,SNRPB)在乳腺癌中的表达及临床意义。方法:运用Oncomine数据库搜索乳腺癌与SNRPB基因相关的数据,通过Kaplan-Meier Plotter数据库分析SNRPB基因与乳腺癌患者预后的关系。结果:Oncomine数据库中SNRPB基因癌组织／正常组织表达量分析结果共有414个,在癌组织中显著高表达109个,低表达3个。其中13个分析结果显示SNRPB在乳腺癌组织(包括6个侵袭性乳腺癌分析结果)中显著高表达,低表达的分析结果为1个。运用Kaplan-Meier Plotter数据库分析结果显示,高表达SNRPB的乳腺癌患者其总体生存率（OS）、无复发生存率（PFS）、无远处转移生存率（DMFS）显著低于低表达SNRPB的乳腺癌患者(P＜0.05)。结论:SNRPB基因在乳腺癌中高表达,可以作为有效的生物标志物预测乳腺癌患者转移的发生及判断预后,可为乳腺癌的靶向治疗提供依据。