Cohort Network: A Knowledge Graph toward Data Dissemination and Knowledge-Driven Discovery for Cohort Studies

Contemporary environmental health sciences draw on large-scale
longitudinal studies to understand the impact of environmental exposures
and behavior factors on the risk of disease and identify potential
underlying mechanisms. In such studies, cohorts of individuals are
assembled and followed up over time. Each cohort generates hundreds
of publications, which are typically neither coherently organized
nor summarized, hence limiting knowledge-driven dissemination. Hence,
we propose a Cohort Network, a multilayer knowledge graph approach
to extract exposures, outcomes, and their connections. We applied
the Cohort Network on 121 peer-reviewed papers published over the
past 10 years from the Veterans Affairs (VA) Normative Aging Study
(NAS). The Cohort Network visualized connections between exposures
and outcomes across different publications and identified key exposures
and outcomes, such as air pollution, DNA methylation, and lung function.
We demonstrated the utility of the Cohort Network for new hypothesis
generation, e.g., identification of potential mediators of exposure–outcome
associations. The Cohort Network can be used by investigators to summarize
the cohort’s research and facilitate knowledge-driven discovery
and dissemination.