Decision Analytic Modelling in Health Economics R package rdecision version 1.3.1 Classes and functions for modelling health care interventions using decision trees and semi-Markov models. Mechanisms are provided for associating an uncertainty distribution with each source variable and for ensuring transparency of the mathematical relationships between variables. The package terminology follows Briggs "Decision Modelling for Health Economic Evaluation" (2006, ISBN:978-0-19-852662-9). Software Depends: R (>= 4.0.0) Imports: graphics, grDevices, grid, R6, rlang (>= 0.4.2), stats, withr Suggests: DiagrammeR, DiagrammeRsvg, rsvg, knitr, rmarkdown, testthat (>= 3.0.0) Andrew Sims <andrew.sims@newcastle.ac.uk> Comprehensive R Archive Network (CRAN) Andrew Sims [aut, cre] (ORCID: <https://orcid.org/0000-0002-9553-7278>), Kim Keltie [aut] (ORCID: <https://orcid.org/0000-0001-5108-6279>), Paola Cognigni [aut] (ORCID: <https://orcid.org/0000-0001-5418-3103>) GPL-3 2026-07-31 application/tgz https://CRAN.R-project.org/package=rdecision doi:10.32614/CRAN.package.rdecision en-GB