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Simulation of meta-analysis for assessing the impact of study variability on parameter estimates for survival data

Karpova, Irina (2006) Simulation of meta-analysis for assessing the impact of study variability on parameter estimates for survival data. Master's Thesis, University of Pittsburgh. (Unpublished)

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Abstract

Meta-analysis is a statistical method of public health relevance that is used to combine the results of individual studies which evaluate the same treatment effect. A test that is commonly used to decide whether the results are homogeneous, and determines model choice for meta-analysis, is called Cochran's Q-test. A major drawback of the Q-test, when the outcomes are normally distributed, is its low power when the number of studies is small, and excessive power when the number of studies is large. In this thesis, we propose a Cochran's Q--test for survival analysis data. Usingsimulations, we examine how the power of Cochran's test changes with different numbers of studies, different weight allocations per study, and the amount of censored observations. We show that the power increases with the increasing number of studies, but lowers with the increasing number of censored observations, and whenever one study comprises a large proportion of the total weight. We conclude that the test of heterogeneity should not be considered as the only determinant of the model choice for meta-analysis. Other methods such as graphical exploration, stratified analysis, or regression modeling should be used in conjunction with the formal statistical test.


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Details

Item Type: University of Pittsburgh ETD
Status: Unpublished
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Karpova, Irinaikn53@yahoo.com
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairAnderson, Stewart Jsja@pitt.eduSJA
Committee MemberJeong, Jong-Heyonjeong@nsabp.pitt.eduJJEONG
Committee MemberKip, Kevin Ekipk@edc.pitt.edu
Date: 1 June 2006
Date Type: Completion
Defense Date: 10 April 2006
Approval Date: 1 June 2006
Submission Date: 12 April 2006
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Institution: University of Pittsburgh
Schools and Programs: Graduate School of Public Health > Biostatistics
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: Cochran's test
Other ID: http://etd.library.pitt.edu/ETD/available/etd-04122006-125729/, etd-04122006-125729
Date Deposited: 10 Nov 2011 19:36
Last Modified: 15 Nov 2016 13:39
URI: http://d-scholarship.pitt.edu/id/eprint/7037

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