scholarly journals Statistical Diagnosis for Random Right Censored Data Based on Kaplan-Meier Product Limit Estimate

2014 ◽  
Vol 04 (04) ◽  
pp. 313-317
Author(s):  
Shuling Wang ◽  
Xiaohong Deng ◽  
Lin Zheng
Keyword(s):  
Censored Data ◽  
Right Censored Data ◽  
Kaplan Meier ◽  
Product Limit ◽  
Limit Estimate

Impact of Additional Cytogenetic Changes and FLT3 Mutations on the Outcome of Patients with Newly Diagnosed Acute Promyelocytic Leukaemia Treated with Single Agent Arsenic Trioxide.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2346-2346
Author(s):  
Vikram Mathews ◽  
Maria Thomas ◽  
Vivi M. Srivastava ◽  
Ezhilarasi Chendamarai ◽  
Biju George ◽  
...  
Keyword(s):  
Single Agent ◽  
Newly Diagnosed ◽  
Mutation Status ◽  
Activating Mutations ◽  
Flt3 Mutation ◽  
Kaplan Meier ◽  
Significant Difference ◽  
Cytogenetic Changes ◽  
Product Limit ◽  
Limit Estimate

Abstract The efficacy of single agent arsenic trioxide (ATO) in the management of relapsed and newly diagnosed patients with acute promyelocytic leukaemia (APL) has been established. The impact of FLT3 activating mutations and additional cytogenetic changes in newly diagnosed patients with APL treated with single agent ATO has never been reported. Between January 1998 and April 2005, 98 newly diagnosed cases of PML-RARα positive APL were treated with a regimen of single agent ATO at our centre. FLT3 activating mutations were seen in 33% (FLT3-ITD - 21.3%, D835V- 11.7%). Of the 69 patients evaluated for additional cytogenetic findings, 76.8% had an isolated t(15;17) while 23.2% had t(15;17) along with additional cytogenetic findings. The presence of a FLT3 mutation was significantly associated with a higher mean white cell count (18.11±23.74 vs. 8.04±21.44, P=0.024) and a bcr3 PML-RARα isoform (48.4% vs. 20.6%, P=0.006). There was also a significant delay in achieving a molecular remission (MR) among patients with a FLT3 mutation as noted by the number of patients who were in MR prior to onset of consolidation therapy (60.9% vs. 85.7%, P=0.031). There was no significant difference in the hematological remission rate (CR), time to CR or early mortality between the group with and without a FLT3 mutation. At a median follow up of 20 months (range: 4 – 97), the 3 year Kaplan-Meier estimate of OS, EFS and DFS for patients with a FLT3 mutation was 82.51±7.24, 77.01±8.6, 88.82±7.48 percent while for those without a FLT3 mutation it was 92.06±3.4, 80.45±5.86, 89.02±5.31 percent. Statistical analysis of these survival curves by a log rank test did not reveal any significant difference between the two groups [Figure 1]. The presence of additional cytogenetic changes was not associated with any significant differences in the clinical or laboratory parameters at presentation. It also did not have an impact on the CR, MR, EFS, DFS or OS. Neither FLT3 activating mutations nor additional cytogenetic changes have a significant impact on the outcome of newly diagnosed patients with APL treated with single agent ATO in the short term. Whether either of these two parameters will affect long term outcome remains to be seen. Figure 1: Kaplan-Meier product limit estimate of EFS based on FLT3 mutation status (n=94). Figure 1:. Kaplan-Meier product limit estimate of EFS based on FLT3 mutation status (n=94).

SELECTING THE BEST PERFORMING WEIBULL ESTIMATION METHOD FOR RANDOMLY RIGHT CENSORED DATA

2010 ◽  
Vol 17 (02) ◽  
pp. 105-118
Author(s):  
JONATHAN J. BATES ◽  
JOSÉ L. ZAYAS-CASTRO
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Estimator ◽  
Censored Data ◽  
Estimation Method ◽  
Estimation Methods ◽  
Likelihood Estimator ◽  
Right Censored Data ◽  
Kaplan Meier ◽  
Piecewise Exponential ◽  
Two Parameter

A total of nine methods are compared and tables are presented for selecting the best performing estimator for a two-parameter Weibull distribution using randomly right censored data. The results indicate that a best performing method can be selected given a certain sample size, censoring level, and shape parameter range. Such a comparison of estimators is necessary as the best performing method is shown to vary across these values. The estimation methods tested include the Maximum Likelihood Estimator, Kaplan-Meier Estimator, Piecewise Exponential Estimator, Földes, Rejt, and Winter Estimator, Klein, Lee, and Moeschberger Partially Parametric Estimator, Ross Estimator, White Estimator, Bain and Engelhardt Estimator, and the Modified Profile Maximum Likelihood Estimator. Recommendations are provided for applying the studied approach to other types of data and distributions.

Estimation of Bivariate Survival Function from Random Censored Data with Poisson Sample Size

2020 ◽  
Vol 72 (2) ◽  
pp. 111-121
Author(s):  
Abdurakhim Akhmedovich Abdushukurov ◽  
Rustamjon Sobitkhonovich Muradov
Keyword(s):  
Relative Risk ◽  
Sample Size ◽  
Censored Data ◽  
Survival Function ◽  
Survival Functions ◽  
Power Structures ◽  
Bivariate Survival ◽  
Empirical Estimates ◽  
Bivariate Survival Function ◽  
Product Limit

At the present time there are several approaches to estimation of survival functions of vectors of lifetimes. However, some of these estimators either are inconsistent or not fully defined in range of joint survival functions and therefore not applicable in practice. In this article, we consider three types of estimates of exponential-hazard, product-limit, and relative-risk power structures for the bivariate survival function, when replacing the number of summands in empirical estimates with a sequence of Poisson random variables. It is shown that these estimates are asymptotically equivalent. AMS 2000 subject classification: 62N01

scholarly journals Weighted expectile regression for right‐censored data

2021 ◽  
Author(s):  
Alexander Seipp ◽  
Verena Uslar ◽  
Dirk Weyhe ◽  
Antje Timmer ◽  
Fabian Otto‐Sobotka
Keyword(s):  
Censored Data ◽  
Right Censored Data ◽  
Expectile Regression
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