The goal of this research is to develop new statistical methods for analyzing, interpreting, and designing clinical trials for patients with Acquired Immune Deficiency Syndrome (AIDS). Methods will be developed to model the relationship of longitudinally measured biological variables such as CD4 counts to clinical outcome such as death or time to AIDS. In particular, we will develop methods that will account for the bias that occurs when the variables are missing over time in a non-random fashion as well as being measured with error. The primary purpose of this research is to study whether biological variables could be identified that may be used as early surrogates of clinical outcome. We shall develop tests of hypotheses and parameter estimates for censored survival data that are more efficient by incorporating auxiliary time dependent prognostic variables to recover information that is lost due to censoring. We shall develop a comprehensive approach for monitoring AIDS clinical trials whose primary endpoint is time to event using group sequential boundaries. In particular, we shall show how to apply these methods to arbitrary parametric models as well as some nonparametric models.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI031789-04
Application #
2066719
Study Section
AIDS and Related Research Study Section 2 (ARRB)
Project Start
1991-07-01
Project End
1997-06-30
Budget Start
1994-07-01
Budget End
1995-06-30
Support Year
4
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Harvard University
Department
Biostatistics & Other Math Sci
Type
Schools of Public Health
DUNS #
082359691
City
Boston
State
MA
Country
United States
Zip Code
02115
Yuan, Shuai; Zhang, Hao Helen; Davidian, Marie (2012) Variable selection for covariate-adjusted semiparametric inference in randomized clinical trials. Stat Med 31:3789-804
Tsiatis, Anastasios A; Davidian, Marie; Cao, Weihua (2011) Improved doubly robust estimation when data are monotonely coarsened, with application to longitudinal studies with dropout. Biometrics 67:536-45
Thomas, Laine; Stefanski, Leonard; Davidian, Marie (2011) A moment-adjusted imputation method for measurement error models. Biometrics 67:1461-70
Cao, Weihua; Tsiatis, Anastasios A; Davidian, Marie (2009) Improving efficiency and robustness of the doubly robust estimator for a population mean with incomplete data. Biometrika 96:723-734
Serroyen, Jan; Molenberghs, Geert; Verbeke, Geert et al. (2009) Non-linear Models for Longitudinal Data. Am Stat 63:378-388
Johnson, Brent A; Tsiatis, Anastasios A (2004) Estimating mean response as a function of treatment duration in an observational study, where duration may be informatively censored. Biometrics 60:315-23
Leon, Selene; Tsiatis, Anastasios A; Davidian, Marie (2003) Semiparametric estimation of treatment effect in a pretest-posttest study. Biometrics 59:1046-55
Song, Xiao; Davidian, Marie; Tsiatis, Anastasios A (2002) A semiparametric likelihood approach to joint modeling of longitudinal and time-to-event data. Biometrics 58:742-53
Lunceford, Jared K; Davidian, Marie; Tsiatis, Anastasios A (2002) Estimation of survival distributions of treatment policies in two-stage randomization designs in clinical trials. Biometrics 58:48-57
Bang, Heejung; Tsiatis, Anastasios A (2002) Median regression with censored cost data. Biometrics 58:643-9

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