A confounding bridge approach for double negative control inference on causal effects

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Miao, Wang, Shi, Xu, Li, Yilin, Tchetgen, Eric Tchetgen
Format: Preprint
Published: 2018
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912016390684672
author Miao, Wang
Shi, Xu
Li, Yilin
Tchetgen, Eric Tchetgen
author_facet Miao, Wang
Shi, Xu
Li, Yilin
Tchetgen, Eric Tchetgen
contents Unmeasured confounding is a key challenge for causal inference. In this paper, we establish a framework for unmeasured confounding adjustment with negative control variables. A negative control outcome is associated with the confounder but not causally affected by the exposure in view, and a negative control exposure is correlated with the primary exposure or the confounder but does not causally affect the outcome of interest. We introduce an outcome confounding bridge function that depicts the relationship between the confounding effects on the primary outcome and the negative control outcome, and we incorporate a negative control exposure to identify the bridge function and the average causal effect. We also consider the extension to the positive control setting by allowing for nonzero causal effect of the primary exposure on the control outcome. We illustrate our approach with simulations and apply it to a study about the short-term effect of air pollution on mortality. Although a standard analysis shows a significant acute effect of PM2.5 on mortality, our analysis indicates that this effect may be confounded, and after double negative control adjustment, the effect is attenuated toward zero.
format Preprint
id arxiv_https___arxiv_org_abs_1808_04945
institution arXiv
publishDate 2018
record_format arxiv
spellingShingle A confounding bridge approach for double negative control inference on causal effects
Miao, Wang
Shi, Xu
Li, Yilin
Tchetgen, Eric Tchetgen
Methodology
Unmeasured confounding is a key challenge for causal inference. In this paper, we establish a framework for unmeasured confounding adjustment with negative control variables. A negative control outcome is associated with the confounder but not causally affected by the exposure in view, and a negative control exposure is correlated with the primary exposure or the confounder but does not causally affect the outcome of interest. We introduce an outcome confounding bridge function that depicts the relationship between the confounding effects on the primary outcome and the negative control outcome, and we incorporate a negative control exposure to identify the bridge function and the average causal effect. We also consider the extension to the positive control setting by allowing for nonzero causal effect of the primary exposure on the control outcome. We illustrate our approach with simulations and apply it to a study about the short-term effect of air pollution on mortality. Although a standard analysis shows a significant acute effect of PM2.5 on mortality, our analysis indicates that this effect may be confounded, and after double negative control adjustment, the effect is attenuated toward zero.
title A confounding bridge approach for double negative control inference on causal effects
topic Methodology
url https://arxiv.org/abs/1808.04945