| Sample size calculation for the proportional hazards cure model. | |
| | |
MedLine Citation:
|
PMID: 22786805 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
In clinical trials with time-to-event endpoints, it is not uncommon to see a significant proportion of patients being cured (or long-term survivors), such as trials for the non-Hodgkins lymphoma disease. The popularly used sample size formula derived under the proportional hazards (PH) model may not be proper to design a survival trial with a cure fraction, because the PH model assumption may be violated. To account for a cure fraction, the PH cure model is widely used in practice, where a PH model is used for survival times of uncured patients and a logistic distribution is used for the probability of patients being cured. In this paper, we develop a sample size formula on the basis of the PH cure model by investigating the asymptotic distributions of the standard weighted log-rank statistics under the null and local alternative hypotheses. The derived sample size formula under the PH cure model is more flexible because it can be used to test the differences in the short-term survival and/or cure fraction. Furthermore, we also investigate as numerical examples the impacts of accrual methods and durations of accrual and follow-up periods on sample size calculation. The results show that ignoring the cure rate in sample size calculation can lead to either underpowered or overpowered studies. We evaluate the performance of the proposed formula by simulation studies and provide an example to illustrate its application with the use of data from a melanoma trial. Copyright © 2012 John Wiley & Sons, Ltd. |
| | |
Authors:
|
Songfeng Wang; Jiajia Zhang; Wenbin Lu |
Related Documents
:
|
23486985 - Kinematic structure at the early flight position in ski jumping. 23178735 - Expected estimating equations via em for proportional hazards regression with covariate... 23408965 - An extension of ppls-da for classification and comparison to ordinary pls-da. 23112675 - Accuracy enhancement of inertial sensors utilizing high resolution spectral analysis. 16604635 - Ford motor company nde facility shielding design. 10210615 - Spatial mislocalization of eeg electrodes -- effects on accuracy of dipole estimation. |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2012-7-11 |
Journal Detail:
|
Title: Statistics in medicine Volume: - ISSN: 1097-0258 ISO Abbreviation: - Publication Date: 2012 Jul |
Date Detail:
|
Created Date: 2012-7-12 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8215016 Medline TA: Stat Med Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Copyright Information:
|
Copyright © 2012 John Wiley & Sons, Ltd. |
Affiliation:
|
Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC 29208, U.S.A.. songfeng@gmail.com. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Cognition in nephropathic cystinosis: pattern of expression in heterozygous carriers.
Next Document: Polar opposites: Fine-tuning cytokinesis through SIN asymmetry.