title: Causal mediation analysis in the context of clinical research.
abstract: Clinical researches usually collected numerous intermediate variables besides treatment and outcome. These variables are often incorrectly treated as confounding factors and are thus controlled using a variety of multivariable regression models depending on the types of outcome variable. However, these methods fail to disentangle underlying mediating processes. Causal mediation analysis (CMA) is a method to dissect total effect of a treatment into direct and indirect effect. The indirect effect is transmitted via mediator to the outcome. The mediation package is designed to perform CMA under the assumption of sequential ignorability. It reports average causal mediation effect (ACME), average direct effect (ADE) and total effect. Also, the package provides visualization tool for these estimated effects. Sensitivity analysis is designed to examine whether the results are robust to the violation of the sequential ignorability assumption since the assumption has been criticized to be too strong to be satisfied in research practice.
authors.affiliation: Department of Emergency Medicine, Sir Run-Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China;; Jinhua Hospital of Zhejiang University, Jinhua 321000, China.
authors.forename: Zhongheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Joseph. J. Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Chanmin
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology, Emergency Medicine, Critical Care Medicine and Pain Therapy. Ziekenhuis Oost-Limburg, Genk, Belgium.
authors.forename: Sven
authors.initials: S
authors.lastname: Van Poucke
authors.affiliation: liver Research Center of the First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
authors.forename: Su
authors.initials: S
authors.lastname: Lin
authors.affiliation: Department of Critical Care Medicine, Sir Run-Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lan
keywords: Causal mediation analysis (CMA); clinical research; mediator; sensitivity analysis