1 citations · 2 across the 6 of their papers we have counts for
6 papers
Associations between pain-management treatments and opioid use disorder risk among Medicaid patients
Kara E. Rudolph, Nicholas T. Williams, Ivan Diaz +7
Introduction: Chronic pain patients are at increased risk of opioid-misuse. Less is known about the unique risk conferred by each pain-management treatment, as treatments are typic…
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…
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…
Efficient and flexible causal mediation with time-varying mediators, treatments, and confounders
Iván Díaz, Nicholas Williams, Kara E. Rudolph
Interventional effects have been proposed as a solution to the unidentifiability of natural (in)direct effects under mediator-outcome confounders affected by the exposure. Such con…
Causal mediation with instrumental variables
Kara E. Rudolph, Nicholas Williams, Ivan Diaz
Mediation analysis is a strategy for understanding the mechanisms by which treatments or interventions affect later outcomes. Mediation analysis is frequently applied in randomized…