To cite package ‘Jcvrisk’ in publications use:

  Okumiyama H, Fujii R (2024). _Jcvrisk: Risk Calculator for
  Cardiovascular Disease in Japan_. R package version 0.1.0,
  <https://CRAN.R-project.org/package=Jcvrisk>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {Jcvrisk: Risk Calculator for Cardiovascular Disease in Japan},
    author = {Hiroshi Okumiyama and Ryosuke Fujii},
    year = {2024},
    note = {R package version 0.1.0},
    url = {https://CRAN.R-project.org/package=Jcvrisk},
  }