In the past year investigators and staff on this project developed nonparametric sequential methods for evaluation of diagnostic biomarkers. They investigated a two-stage procedures for selecting the best diagnostic biomarkers to control the probability of incorrect selection. Methods for point and interval estimation of accuracies of a binary diagnostic biomarkers were developed following group sequential evaluation of the biomarkers'sensitivity and specificity. For biomarkers whose measurements are subject to limits of detection, the group developed maximum likelihood ratio tests for comparing the discriminatory ability of biomarkers subject to limit of detection. To design comparative diagnostic accuracy studies an adaptive approach was developed to maintain the study power due to misspecifications of nuisance parameters.

Project Start
Project End
Budget Start
Budget End
Support Year
5
Fiscal Year
2013
Total Cost
$66,307
Indirect Cost
City
State
Country
Zip Code
Albert, Paul S; Liu, Aiyi; Nansel, Tonja (2014) Efficient logistic regression designs under an imperfect population identifier. Biometrics 70:175-84
Tang, Liansheng Larry; Liu, Aiyi; Chen, Zhen et al. (2013) Nonparametric ROC summary statistics for correlated diagnostic marker data. Stat Med 32:2209-20
Tang, Liansheng Larry; Kang, Le; Liu, Chunling et al. (2013) An additive selection of markers to improve diagnostic accuracy based on a discriminatory measure. Acad Radiol 20:854-62
Kang, Le; Liu, Aiyi; Tian, Lili (2013) Linear combination methods to improve diagnostic/prognostic accuracy on future observations. Stat Methods Med Res :
Liu, Aiyi; Wu, Chengqing; Yu, Kai F (2008) Two-stage procedures for selecting the best diagnostic biomarkers. Philos Transact A Math Phys Eng Sci 366:2293-9
Wu, Chengqing; Liu, Aiyi; Yu, Kai F (2008) An adaptive approach to designing comparative diagnostic accuracy studies. J Biopharm Stat 18:116-25
Vexler, Albert; Liu, Aiyi; Eliseeva, Ekaterina et al. (2008) Maximum likelihood ratio tests for comparing the discriminatory ability of biomarkers subject to limit of detection. Biometrics 64:895-903
Liu, Aiyi; Wu, Chengqing; Schisterman, Enrique F (2008) Nonparametric sequential evaluation of diagnostic biomarkers. Stat Med 27:1667-78
Shu, Yu; Liu, Aiyi; Li, Zhaohai (2008) Point and interval estimation of accuracies of a binary medical diagnostic test following group sequential testing. Philos Transact A Math Phys Eng Sci 366:2335-45