Grant Number:	5R01CA051962-20 Interpret this number
Primary Investigator:	Tsiatis, Anastasios
Organization:	North Carolina State University Raleigh
Project Title:	Statistical Analysis of Complex Data in Cancer
Fiscal Year:	2010

DESCRIPTION (provided by applicant): The major purpose of this research is to develop robust and efficient methods for the analysis and design of complex data that are encountered in cancer clinical trials. The research will focus on four broad topics. 1. We will develop a comprehensive theory that uses auxiliary baseline auxiliary covariates that are correlated with the primary response variable to develop estimators and tests of treatment difference in randomized clinical trials that are more efficient than current methods. 2. We will extend the methodology from Aim 1. to consider cases where the primary outcome is missing on a subgroup of patients because of loss to follow-up. 3. Semi parametric locally-efficient estimators for the regression parameters in a proportional hazards model that models the relationship of survival and longitudinal data through common subject-specific random effects using a joint model will be developed that are robust to misspecification of the distribution of the random effects. This methodology will also be applicable to finding estimators for the regression parameters in a proportional hazards model with covariates that are measured with error. 4. Two-stage and multi-stage randomized clinical trials is an efficient way of conducting studies with the primary purpose of comparing different time-dependent (adaptive) treatment policies. We will develop weighted log rank tests that can validly be used to test for differences in treatment policies with such designs using censored survival data. Relevance: Because of limited resources, either money or patients, it is imperative that we take advantage of state of the art designs and analyses to get the most efficient use of the data that are collected in a clinical trial so that we have the best chance of answering the scientifically relevant questions. At the same time we want the methods to be as broadly applicable as possible without having to make unnecessary assumptions. The methods that will be developed will use cutting edge theory to accomplish these goals.




Properties of Estimators in Exponential Family Settings with Observation-based Stopping Rules.
Authors: Milanzi E. , Molenberghs G. , Alonso A. , Kenward M.G. , Verbeke G. , Tsiatis A.A. , Davidian M. .
Source: Journal Of Biometrics & Biostatistics, 2016 Feb; 7(1), .
PMID: 27175309
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Estimation After a Group Sequential Trial.
Authors: Milanzi E. , Molenberghs G. , Alonso A. , Kenward M.G. , Tsiatis A.A. , Davidian M. , Verbeke G. .
Source: Statistics In Biosciences, 2015 Oct; 7(2), p. 187-205.
PMID: 26478751
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Q- and A-learning Methods for Estimating Optimal Dynamic Treatment Regimes.
Authors: Schulte P.J. , Tsiatis A.A. , Laber E.B. , Davidian M. .
Source: Statistical Science : A Review Journal Of The Institute Of Mathematical Statistics, 2014 Nov; 29(4), p. 640-661.
PMID: 25620840
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On random sample size, ignorability, ancillarity, completeness, separability, and degeneracy: sequential trials, random sample sizes, and missing data.
Authors: Molenberghs G. , Kenward M.G. , Aerts M. , Verbeke G. , Tsiatis A.A. , Davidian M. , Rizopoulos D. .
Source: Statistical Methods In Medical Research, 2014 Feb; 23(1), p. 11-41.
PMID: 22514029
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Assessing the causal effect of organ transplantation on the distribution of residual lifetime.
Authors: Vock D.M. , Tsiatis A.A. , Davidian M. , Laber E.B. , Tsuang W.M. , Finlen Copeland C.A. , Palmer S.M. .
Source: Biometrics, 2013 Dec; 69(4), p. 820-9.
PMID: 24128090
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A robust method for estimating optimal treatment regimes.
Authors: Zhang B. , Tsiatis A.A. , Laber E.B. , Davidian M. .
Source: Biometrics, 2012 Dec; 68(4), p. 1010-8.
PMID: 22550953
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Time-varying latent effect model for longitudinal data with informative observation times.
Authors: Cai N. , Lu W. , Zhang H.H. .
Source: Biometrics, 2012 Dec; 68(4), p. 1093-102.
PMID: 23025338
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Mixed model analysis of censored longitudinal data with flexible random-effects density.
Authors: Vock D.M. , Davidian M. , Tsiatis A.A. , Muir A.J. .
Source: Biostatistics (oxford, England), 2012 Jan; 13(1), p. 61-73.
PMID: 21914727
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Semiparametric estimation of treatment effect with time-lagged response in the presence of informative censoring.
Authors: Lu X. , Tsiatis A.A. .
Source: Lifetime Data Analysis, 2011 Oct; 17(4), p. 566-93.
PMID: 21706378
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Discussion of "Connections Between Survey Calibration Estimators and Semiparametric Models for Incomplete Data" by T. Lumley, P.A. Shaw & J.Y. Dai.
Authors: Tsiatis A.A. , Davidian M. .
Source: International Statistical Review = Revue Internationale De Statistique, 2011-08-01 00:00:00.0; 79(2), p. 221-223.
PMID: 21927532
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Improved doubly robust estimation when data are monotonely coarsened, with application to longitudinal studies with dropout.
Authors: Tsiatis A.A. , Davidian M. , Cao W. .
Source: Biometrics, 2011 Jun; 67(2), p. 536-45.
PMID: 20731640
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Inference on treatment effects from a randomized clinical trial in the presence of premature treatment discontinuation: the SYNERGY trial.
Authors: Zhang M. , Tsiatis A.A. , Davidian M. , Pieper K.S. , Mahaffey K.W. .
Source: Biostatistics (oxford, England), 2011 Apr; 12(2), p. 258-69.
PMID: 20797983
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Multiple imputation approaches for the analysis of dichotomized responses in longitudinal studies with missing data.
Authors: Lu K. , Jiang L. , Tsiatis A.A. .
Source: Biometrics, 2010 Dec; 66(4), p. 1202-8.
PMID: 20337628
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A generalized estimator of the attributable benefit of an optimal treatment regime.
Authors: Brinkley J. , Tsiatis A. , Anstrom K.J. .
Source: Biometrics, 2010 Jun; 66(2), p. 512-22.
PMID: 19508237
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Improving efficiency and robustness of the doubly robust estimator for a population mean with incomplete data.
Authors: Cao W. , Tsiatis A.A. , Davidian M. .
Source: Biometrika, 2009 Sep; 96(3), p. 723-734.
PMID: 20161511
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'Smooth' inference for survival functions with arbitrarily censored data.
Authors: Doehler K. , Davidian M. .
Source: Statistics In Medicine, 2008-11-20 00:00:00.0; 27(26), p. 5421-39.
PMID: 18613273
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Covariate adjustment for two-sample treatment comparisons in randomized clinical trials: a principled yet flexible approach.
Authors: Tsiatis A.A. , Davidian M. , Zhang M. , Lu X. .
Source: Statistics In Medicine, 2008-10-15 00:00:00.0; 27(23), p. 4658-77.
PMID: 17960577
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Improving efficiency of inferences in randomized clinical trials using auxiliary covariates.
Authors: Zhang M. , Tsiatis A.A. , Davidian M. .
Source: Biometrics, 2008 Sep; 64(3), p. 707-15.
PMID: 18190618
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Comment: Demystifying Double Robustness: A Comparison of Alternative Strategies for Estimating a Population Mean from Incomplete Data.
Authors: Tsiatis A.A. , Davidian M. .
Source: Statistical Science : A Review Journal Of The Institute Of Mathematical Statistics, 2007; 22(4), p. 569-573.
PMID: 18516239
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Adaptive two-stage designs in phase II clinical trials.
Authors: Banerjee A. , Tsiatis A.A. .
Source: Statistics In Medicine, 2006-10-15 00:00:00.0; 25(19), p. 3382-95.
PMID: 16479547
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Semiparametric Estimation of Treatment Effect in a Pretest-Posttest Study with Missing Data.
Authors: Davidian M. , Tsiatis A.A. , Leon S. .
Source: Statistical Science : A Review Journal Of The Institute Of Mathematical Statistics, 2005 Aug; 20(3), p. 261-301.
PMID: 19081743
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Comparison between two partial likelihood approaches for the competing risks model with missing cause of failure.
Authors: Lu K. , Tsiatis A.A. .
Source: Lifetime Data Analysis, 2005 Mar; 11(1), p. 29-40.
PMID: 15747588
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Estimating mean response as a function of treatment duration in an observational study, where duration may be informatively censored.
Authors: Johnson B.A. , Tsiatis A.A. .
Source: Biometrics, 2004 Jun; 60(2), p. 315-23.
PMID: 15180656
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Semiparametric estimation of treatment effect in a pretest-posttest study.
Authors: Leon S. , Tsiatis A.A. , Davidian M. .
Source: Biometrics, 2003 Dec; 59(4), p. 1046-55.
PMID: 14969484
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A semiparametric likelihood approach to joint modeling of longitudinal and time-to-event data.
Authors: Song X. , Davidian M. , Tsiatis A.A. .
Source: Biometrics, 2002 Dec; 58(4), p. 742-53.
PMID: 12495128
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Median regression with censored cost data.
Authors: Bang H. , Tsiatis A.A. .
Source: Biometrics, 2002 Sep; 58(3), p. 643-9.
PMID: 12229999
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Causal inference on the difference of the restricted mean lifetime between two groups.
Authors: Chen P.Y. , Tsiatis A.A. .
Source: Biometrics, 2001 Dec; 57(4), p. 1030-8.
PMID: 11764241
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Multiple imputation methods for estimating regression coefficients in the competing risks model with missing cause of failure.
Authors: Lu K. , Tsiatis A.A. .
Source: Biometrics, 2001 Dec; 57(4), p. 1191-7.
PMID: 11764260
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Utilizing propensity scores to estimate causal treatment effects with censored time-lagged data.
Authors: Anstrom K.J. , Tsiatis A.A. .
Source: Biometrics, 2001 Dec; 57(4), p. 1207-18.
PMID: 11764262
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Testing equality of survival functions of quality-adjusted lifetime.
Authors: Zhao H. , Tsiatis A.A. .
Source: Biometrics, 2001 Sep; 57(3), p. 861-7.
PMID: 11550938
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Testing for differences in survival with delayed ascertainment.
Authors: Fine J.P. , Tsiatis A.A. .
Source: Biometrics, 2000 Mar; 56(1), p. 145-53.
PMID: 10783789
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Efficient estimation of the distribution of quality-adjusted survival time.
Authors: Zhao H. , Tsiatis A.A. .
Source: Biometrics, 1999 Dec; 55(4), p. 1101-7.
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Estimating the parameters in the Cox model when covariate variables are measured with error.
Authors: Hu P. , Tsiatis A.A. , Davidian M. .
Source: Biometrics, 1998 Dec; 54(4), p. 1407-19.
PMID: 9883541
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Evaluating surrogate markers of clinical outcome when measured with error.
Authors: Dafni U.G. , Tsiatis A.A. .
Source: Biometrics, 1998 Dec; 54(4), p. 1445-62.
PMID: 9883544
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The use of simulation and bootstrap in information-based group sequential studies.
Authors: Scharfstein D.O. , Tsiatis A.A. .
Source: Statistics In Medicine, 1998-01-15 00:00:00.0; 17(1), p. 75-87.
PMID: 9463851
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Semiparametric efficient estimation in the generalized odds-rate class of regression models for right-censored time-to-event data.
Authors: Scharfstein D.O. , Tsiatis A.A. , Gilbert P.B. .
Source: Lifetime Data Analysis, 1998; 4(4), p. 355-91.
PMID: 9880995
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Interleukin 3-dependent survival by the Akt protein kinase.
Authors: Songyang Z. , Baltimore D. , Cantley L.C. , Kaplan D.R. , Franke T.F. .
Source: Proceedings Of The National Academy Of Sciences Of The United States Of America, 1997-10-14 00:00:00.0; 94(21), p. 11345-50.
PMID: 9326612
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Nonparametric survival estimation using prognostic longitudinal covariates.
Authors: Murray S. , Tsiatis A.A. .
Source: Biometrics, 1996 Mar; 52(1), p. 137-51.
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Exact permutational tests for group sequential clinical trials.
Authors: Mehta C.R. , Patel N. , Senchaudhuri P. , Tsiatis A. .
Source: Biometrics, 1994 Dec; 50(4), p. 1042-53.
PMID: 7786986
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Spline-based tests in survival analysis.
Authors: Gray R.J. .
Source: Biometrics, 1994 Sep; 50(3), p. 640-52.
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A Bayesian analysis of institutional effects in a multicenter cancer clinical trial.
Authors: Gray R.J. .
Source: Biometrics, 1994 Mar; 50(1), p. 244-53.
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