Ontology highlight
ABSTRACT: Purpose
Inversed probability weighted (IPW) estimators are commonly used to adjust for time-fixed or time-varying confounders. However, in high-dimensional settings, including all identified confounders may result in unstable weights leading to higher variance. We aimed to develop a visualization tool demonstrating the impact of each confounder on the bias and variance of IPW estimates, as well as the propensity score overlap.Methods
A SAS macro was developed for this visualization tool and we demonstrate how this tool can be used to identify potentially problematic confounders of the association of statin use after myocardial infarction on one-year mortality in a plasmode simulation study using a cohort of 39,792 patients from the UK (1998-2012).Results
Through the tool's output, we can identify problematic confounders (two instrumental variables) and important confounders by comparing the estimated psuedo MSE with that from the fully adjusted model and propensity score overlap plot.Conclusion
Our results suggest that the analytic impact of all confounders should be considered carefully when fitting IPW estimators.
SUBMITTER: Yu YH
PROVIDER: S-EPMC7864095 | biostudies-literature | 2020 Jan
REPOSITORIES: biostudies-literature
Yu Ya-Hui YH Filion Kristian B KB Bodnar Lisa M LM Brooks Maria M MM Platt Robert W RW Himes Katherine P KP Naimi Ashley I AI
Annals of epidemiology 20191213
<h4>Purpose</h4>Inversed probability weighted (IPW) estimators are commonly used to adjust for time-fixed or time-varying confounders. However, in high-dimensional settings, including all identified confounders may result in unstable weights leading to higher variance. We aimed to develop a visualization tool demonstrating the impact of each confounder on the bias and variance of IPW estimates, as well as the propensity score overlap.<h4>Methods</h4>A SAS macro was developed for this visualizati ...[more]