Identifying and Estimating Causal Direct Effects Under Unmeasured Confounding

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Boileau, Philippe, Hejazi, Nima S., Malenica, Ivana, Gilbert, Peter B., Dudoit, Sandrine, van der Laan, Mark J.
Natura: Preprint
Pubblicazione: 2026
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908933065539584
author Boileau, Philippe
Hejazi, Nima S.
Malenica, Ivana
Gilbert, Peter B.
Dudoit, Sandrine
van der Laan, Mark J.
author_facet Boileau, Philippe
Hejazi, Nima S.
Malenica, Ivana
Gilbert, Peter B.
Dudoit, Sandrine
van der Laan, Mark J.
contents Causal mediation analysis provides techniques for defining and estimating effects that may be endowed with mechanistic interpretations. With many scientific investigations seeking to address mechanistic questions, causal direct and indirect effects have garnered much attention. The natural direct and indirect effects, the most widely used among such causal mediation estimands, are limited in their practical utility due to stringent identification requirements. Accordingly, considerable effort has been invested in developing alternative direct and indirect effect decompositions with relaxed identification requirements. Such efforts often yield effect definitions with nuanced and challenging interpretations. By contrast, relatively limited attention has been paid to relaxing the identification assumptions of the natural direct and indirect effects. Motivated by a secondary aim of a recent non-randomized vaccine prospective cohort study (NCT05168813), we present a set of relaxed conditions under which the natural direct effect is identifiable in spite of unobserved baseline confounding of the exposure-mediator pathway; we use this result to investigate the effect mediated by putative immune correlates of protection. Relaxing the commonly used but restrictive cross-world counterfactual independence assumption, we discuss strategies for evaluating the natural direct effect in non-randomized settings that arise in the analysis of vaccine studies. We revisit prior studies of semi-parametric efficiency theory to demonstrate the construction of flexible, multiply robust estimators of the natural direct effect and discuss efficient estimation strategies that do not place restrictive modeling assumptions on nuisance functions.
format Preprint
id arxiv_https___arxiv_org_abs_2604_01501
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Identifying and Estimating Causal Direct Effects Under Unmeasured Confounding
Boileau, Philippe
Hejazi, Nima S.
Malenica, Ivana
Gilbert, Peter B.
Dudoit, Sandrine
van der Laan, Mark J.
Methodology
Applications
Machine Learning
Other Statistics
Causal mediation analysis provides techniques for defining and estimating effects that may be endowed with mechanistic interpretations. With many scientific investigations seeking to address mechanistic questions, causal direct and indirect effects have garnered much attention. The natural direct and indirect effects, the most widely used among such causal mediation estimands, are limited in their practical utility due to stringent identification requirements. Accordingly, considerable effort has been invested in developing alternative direct and indirect effect decompositions with relaxed identification requirements. Such efforts often yield effect definitions with nuanced and challenging interpretations. By contrast, relatively limited attention has been paid to relaxing the identification assumptions of the natural direct and indirect effects. Motivated by a secondary aim of a recent non-randomized vaccine prospective cohort study (NCT05168813), we present a set of relaxed conditions under which the natural direct effect is identifiable in spite of unobserved baseline confounding of the exposure-mediator pathway; we use this result to investigate the effect mediated by putative immune correlates of protection. Relaxing the commonly used but restrictive cross-world counterfactual independence assumption, we discuss strategies for evaluating the natural direct effect in non-randomized settings that arise in the analysis of vaccine studies. We revisit prior studies of semi-parametric efficiency theory to demonstrate the construction of flexible, multiply robust estimators of the natural direct effect and discuss efficient estimation strategies that do not place restrictive modeling assumptions on nuisance functions.
title Identifying and Estimating Causal Direct Effects Under Unmeasured Confounding
topic Methodology
Applications
Machine Learning
Other Statistics
url https://arxiv.org/abs/2604.01501