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Activity Number:
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243
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Type:
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Contributed
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Date/Time:
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Tuesday, July 31, 2007 : 8:30 AM to 10:20 AM
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Sponsor:
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Biometrics Section
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| Abstract - #308838 |
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Title:
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Semiparametric Estimation with Recurrent Event Data Under an Informative Monitoring Period
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Author(s):
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Akim Adekpedjou*+ and Edsel A. Pena
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Companies:
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University of South Carolina and University of South Carolina
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Address:
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216 LeConte Building, Columbia, SC, 29208,
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Keywords:
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Informative censoring ; Koziol-Green model ; Martingale ; Semiparametric estimation ; Efficiency
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Abstract:
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We consider a biomedical study which monitors the occurrences of a recurrent event for n subjects over a random observation window for each subject. We assume that the distribution of the random observation window is informative regarding the distribution of event time. The problem of semiparametric estimation of the cumulative hazard and consequently of the gap-time is considered under a model of informative censoring called the Koziol-Green model. We derive a Nelson-Aalen and Kaplan-Meier type estimators respectively for the cumulative hazard and the gap-time distribution function under the specified model. Asymptotic and small sample properties of the proposed estimators are established. The proposed estimators are compared to the nonparametric estimator of the proposed in Pena et al. (2001, JASA) to ascertain any efficiency gain achieved by exploiting the Koziol-Green structure.
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