4 citations · 8 across the 8 of their papers we have counts for
11 papers
More efficient transportation of causal effects using mediators
Xinyi Zhang, Kara E. Rudolph, James Russell Pike +3
We develop flexible semiparametric estimators of the average treatment effect transported to a target population that leverage mediators to achieve identification, and prior knowle…
Everything all at once: On choosing an estimand for multi-component environmental exposures
Kara E. Rudolph, Shodai Inose, Nicholas Williams +4
Many research questions -- particularly those in environmental health -- do not involve binary exposures. In environmental epidemiology, this includes multivariate exposure mixture…
Riesz representers for the rest of us
Nicholas T. Williams, Oliver J. Hines, Kara E. Rudolph
The application of semiparametric efficient estimators, particularly those that leverage machine learning, is rapidly expanding within epidemiology and causal inference. This liter…
Nonparametric estimation of an optimal treatment rule with fused randomized trials and missing effect modifiers
Nicholas Williams, Kara Rudolph, Iván Díaz
A fundamental principle of clinical medicine is that a treatment should only be administered to those patients who would benefit from it. Treatment strategies that assign treatment…
General targeted machine learning for modern causal mediation analysis
Richard Liu, Nicholas T. Williams, Kara E. Rudolph +1
Causal mediation analyses investigate the mechanisms through which causes exert their effects, and are therefore central to scientific progress. The literature on the non-parametri…
Longitudinal Generalizations of the Average Treatment Effect on the Treated for Multi-valued and Continuous Treatments
Herbert Susmann, Nicholas T. Williams, Kara E. Rudolph +1
The Average Treatment Effect on the Treated (ATT) is a common causal parameter defined as the average effect of a binary treatment among the subset of the population receiving trea…
A drug classification pipeline for Medicaid claims using RxNorm
Nicholas Williams, Kara E. Rudolph
Objective: Freely preprocess drug codes recorded in electronic health records and insurance claims to drug classes that may then be used in biomedical research. Materials and Metho…
Identification and estimation of mediational effects of longitudinal modified treatment policies
Brian Gilbert, Katherine L. Hoffman, Nicholas Williams +3
We demonstrate a comprehensive semiparametric approach to causal mediation analysis, addressing the complexities inherent in settings with longitudinal and continuous treatments, c…
Learning Optimal Dynamic Treatment Regimes from Longitudinal Data
Nicholas T. Williams, Katherine L. Hoffman Iván Díaz, Kara E. Rudolph
Studies often report estimates of the average treatment effect. While the ATE summarizes the effect of a treatment on average, it does not provide any information about the effect…
Recanting twins: addressing intermediate confounding in mediation analysis
Tat-Thang Vo, Nicholas Williams, Richard Liu +2
The presence of intermediate confounders, also called recanting witnesses, is a fundamental challenge to the investigation of causal mechanisms in mediation analysis, preventing th…
Two-Step Targeted Minimum-Loss Based Estimation for Non-Negative Two-Part Outcomes
Nicholas T. Williams, Richard Liu, Katherine L. Hoffman +3
Non-negative two-part outcomes are defined as outcomes with a density function that have a zero point mass but are otherwise positive. Examples, such as healthcare expenditure and…