47: Matching-Based Causal Mediation: Application to Smoking Cessation in the PATH Study

Thomas M. Menino Convention & Exhibition Center 

Mediation analysis is a valuable method for investigating mechanisms through which treatments or exposures influence an outcome, with broad applications in biomedical and public health research. Methodological developments include, for example, regression-based approaches and weighting to enable causal interpretation. Although methodological advances have been substantial, the use of matching within causal mediation analysis remains largely unexplored. We introduce a matching-based causal mediation method for settings with a binary mediator and binary outcome. Within the counterfactual framework, our approach estimates natural direct and indirect effects without reliance on strong parametric assumptions. We apply the proposed method to the Population Assessment of Tobacco and Health (PATH) Study to evaluate whether a binary mediator explains the association between e-cigarette use and the outcome of long-term smoking cessation. We assess the performance of our approach through simulation studies under scenarios with common and rare outcomes and in the presence of an exposure-mediator interaction.

Causal inference

Mediation analysis

Matching

Smoking cessation

E-cigarettes 

Section on Statistics in Epidemiology