Document Detail


Accurate confidence limits for quantiles under random censoring.
MedLine Citation:
PMID:  9423256     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In survival analysis, estimates of median survival times in homogeneous samples are often based on the Kaplan-Meier estimator of the survivor function. Confidence intervals for quantiles, such as median survival, are typically constructed via large sample theory or the bootstrap. The former has suspect accuracy for small sample sizes under moderate censoring and the latter is computationally intensive. In this paper, improvements on so-called test-based intervals and reflected intervals (cf., Slud, Byar, and Green, 1984, Biometrics 40, 587-600) are sought. Using the Edgeworth expansion for the distribution of the studentized Nelson-Aalen estimator derived in Strawderman and Wells (1997, Journal of the American Statistical Association 92), we propose a method for producing more accurate confidence intervals for quantiles with randomly censored data. The intervals are very simple to compute, and numerical results using simulated data show that our new test-based interval outperforms commonly used methods for computing confidence intervals for small sample sizes and/or heavy censoring, especially with regard to maintaining specified coverage.
Authors:
R L Strawderman; M I Parzen; M T Wells
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Biometrics     Volume:  53     ISSN:  0006-341X     ISO Abbreviation:  Biometrics     Publication Date:  1997 Dec 
Date Detail:
Created Date:  1998-02-04     Completed Date:  1998-02-04     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370625     Medline TA:  Biometrics     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1399-415     Citation Subset:  IM    
Affiliation:
Department of Biostatistics, University of Michigan, Ann Arbor 48109-2029, USA.
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MeSH Terms
Descriptor/Qualifier:
Biometry / methods
Confidence Intervals*
Humans
Likelihood Functions
Models, Statistical
Reproducibility of Results
Survival Analysis*
Survival Rate*
Treatment Failure
Grant Support
ID/Acronym/Agency:
R01-CA61120/CA/NCI NIH HHS; R01-DK49529/DK/NIDDK NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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