Skip Navigation


Biostatistics Advance Access originally published online on April 28, 2005
Biostatistics 2005 6(4):604-614; doi:10.1093/biostatistics/kxi030
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
6/4/604    most recent
kxi030v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Shen, Y.
Right arrow Articles by Zelen, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Shen, Y.
Right arrow Articles by Zelen, M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2005. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oupjournals.org.

Robust modeling in screening studies: estimation of sensitivity and preclinical sojourn time distribution

Yu Shen*

Department of Biostatistics and Applied Mathematics, M. D. Anderson Cancer Center, University of Texas, Houston, TX 77030, USA yshen{at}mdanderson.org

Marvin Zelen

Department of Biostatistics, Harvard School of Public Health and the Dana-Farber Cancer Institute, Boston, MA 02115, USA

* To whom correspondence should be addressed.

In early-detection clinical trials, quantities such as the sensitivity of the screening modality and the preclinical duration of the disease are important to describe the natural history of the disease and its interaction with a screening program. Assume that the schedule of a screening program is periodic and that the sojourn time in the preclinical state has a piecewise density function. Modeling the preclinical sojourn time distribution as a piecewise density function results in robust estimation of the distribution function. Our aim is to estimate the piecewise density function and the examination sensitivity using both generalized least squares and maximum likelihood methods. We carried out extensive simulations to evaluate the performance of the methods of estimation. The different estimation methods provide complimentary tools to obtain the unknown parameters. The methods are applied to three breast cancer early-detection trials.

Keywords: Piecewise-constant density function; Preclinical duration; Screening clinical trials; Screening sensitivity; Weighted generalized least squares


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.