American Statistical Association
New York City
Metropolitan Area Chapter

Memorial Sloan-Kettering Cancer Center
Biostatistics Seminar

Sharon Xiangwen Xie
Department of Biostatistics & Epidemiology
University of Pennsylvania


In this talk, I discuss some statistical challenges in analyzing neurodegenerative disease research data and the solutions. Developing biomarkers for early detection of neurodegenerative diseases (e.g. Alzheimer’s disease) has drawn great attentions recently. For example, cerebrospinal fluid (CSF) tau is a useful biomarker in detecting Alzheimer's disease (AD). However, the measurement error of these biomarkers cannot be ignored sometimes in the analysis. When an internal reliability sample is available for CSF tau, we have shown that averaging replicates and ignoring measurement error can sometimes lead to serious biases of sensitivity and specificity estimates as well as estimates of hazard ratios. We present bias-correction approaches to remove the biases of accuracy and hazard ratio estimates introduced by measurement error based on an internal reliability sample. Asymptotic distributions were obtained for the proposed estimators. Extensive simulations were conducted to evaluate the proposed approaches. All methods are illustrated using the University of Pennsylvania AD biomarker study or the Framingham study.

Date: Wednesday, September 8, 2010
Time: 4:00 - 5:00 P.M.
Location: Memorial Sloan-Kettering Cancer Center
Department of Epidemiology and Biostatistics
307 East 63rd Street
(between First and Second Avenues)
Room 331
New York, New York
Note: To gain access to the building, please follow the directions by the telephone in the foyer.


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