Seminar Recordings
Designing randomized trials to understand treatment effect heterogeneity
Biostatistics Seminar - November 17, 2020
Elizabeth Tipton, PhD
Associate Professor, Department of Statistics, Northwestern UniversityYSPH Biostatistics Virtual Seminar: “Optimal Doubly Robust Estimation of Heterogeneous Causal Effects"
Edward Kennedy, PhD
Assistant Professor, Department of Statistics & Data Science, Carnegie Mellon UniversityAbstract: Heterogeneous effect estimation plays a crucial role in causal inference, with applications across medicine and social science. Many methods for estimating conditional average treatment effects (CATEs) have been proposed in recent years, but there are important theoretical gaps in understanding if and when such methods are optimal. This is especially true when the CATE has nontrivial structure (e.g., smoothness or sparsity). Our work contributes in several main ways. First, we study a two-stage doubly robust CATE estimator and give a generic model-free error bound, which, despite its generality, yields sharper results than those in the current literature. We apply the bound to derive error rates in nonparametric models with smoothness or sparsity, and give sufficient conditions for oracle efficiency. Underlying our error bound is a general oracle inequality for regression with estimated or imputed outcomes, which is of independent interest; this is the second main contribution. The third contribution is aimed at understanding the fundamental statistical limits of CATE estimation. To that end, we propose and study a local polynomial adaptation of double-residual regression. We show that this estimator can be oracle efficient under even weaker conditions, if used with a specialized form of sample splitting and careful choices of tuning parameters. These are the weakest conditions currently found in the literature, and we conjecture that they are minimal in a minimax sense. We go on to give error bounds in the non-trivial regime where oracle rates cannot be achieved. Some finite-sample properties are explored with simulations.
BIS Seminar: At warp speed: statistics and COVID-19 vaccine development
David Benseker, PhD, MPH, Assistant Professor
Emory University Department of Biostatistics and Bioinformatics.
October 27, 2020
Abstract: One of the best hopes we have of returning life to normal is to bring a safe and effective preventive COVID-19 vaccine to market and make it available to just about everybody around the world. We are in the middle of an unprecedented effort to bring such a vaccine to market. After a recent pressure campaign led by academic scientists, vaccine developers have made public the protocols for their Phase III trials. The release of these protocols has ignited a fierce debate as to whether the designs are appropriate and sufficiently safe-guarded from political pressure for vaccine approval. In this talk I will discuss a few of the complex issues involved in designing Phase III COVID vaccine trials, touching on some key statistical aspects of the trials along the way.
BIS Seminar: A General Framework for Quantile Estimation with Incomplete Data
Linglong Kong
Department of Mathematical and Statistical Sciences
University of Alberta
October 13, 2020
BIS Seminar: Dealing with observed and observed effect moderators wehn estimating population average treatment effects
Elizabeth Stuart
Associate Dean for Education
Bloomberg PRofessor of American Health
September 22, 2020
YSPH Biostatistics Seminar: "Sensitivity Analysis for Observational Studies"
Qingyuan Zhao, University of Cambridge
Biostatistics Seminar: BETS: The dangers of selection bias in early analyses of the coronavirus disease (COVID-19) pandemic
Qingyuan Zhao, Statistical Laboratory, University of Cambridge
May 5, 2020
BIS Seminar - 6.23.2020 - Model-averaged estimation of molecular evolution and natural selection in SARS-COV-1 and SARS-CoV-2 coronaviruses during zoonosis
Jeffrey Townsend, PhD
Elihu Professor of Biostatistics and Professor of Ecology and Evolutionary BiologySequential Bayesian Designs for Rapid Learning in COVID-19 Clinical Trials
Biostatistics Seminar - 6.9.2020
Frank Harrel, Professor of Biostatistics
Vanderbilt University School of MedicineCOVID-19 projections for Connecticut
Associate Professor of Biostatistics, Statistics & Data Science, Operation, and Ecology & Evolutionary Biology
5.25.2020 Biostatistics Seminar
Estimating the early death toll of COVID-19 in the United States
Dan Weinberger, PhD, associate professor of Epidemiology (Microbial Diseases), Yale School of Public Health April 2020 Seminar
