Identifying mediating variables with graphical models: an application to the study of causal pathways in people living with HIV

ABSTRACT

We empirically demonstrate that graphical models can be a valuable tool in the identification of mediating variables in causal pathways. We make use of graphical models to elucidate the causal pathway through which the treatment influences the levels of fatigue and weakness in people living with HIV (PLHIV) based on a secondary analysis of a categorical dataset collected in a behavioral clinical trial: is weakness a mediator for the treatment and fatigue, or is fatigue a mediator for the treatment and weakness? Causal mediation analysis could not offer any definite answers to these questions.

KEYWORDS:

• Contingency tables
• graphical models
• loglinear models
• HIV
• mediation

Acknowledgments

The authors would like to thank the members of the International Nursing Network for HIV/AIDS Research for providing access to data used in this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Joachim G. Voss  http://orcid.org/0000-0002-8072-6244

Additional information

Funding

The work of AD was partially supported by the National Science Foundation (Division of Mathematical Sciences) Grant DMS/MPS-1737746 to the University of Washington.