cchs: An R Package for Stratified Case-Cohort Studies

The cchs package contains a function, also called cchs, for analyzing data from a stratified case-cohort study, as used in epidemiology. For data from this type of study, cchs calculates Estimator III of Borgan et al. (2000), which is a score-unbiased estimator for the regression coefficients in the Cox proportional hazards model. From the user’s point of view, the function is similar to coxph (in the survival package) and other widely used model-fitting functions. Convenient software has not previously been available for Estimator III since it is complicated to calculate. SAS and S-Plus code-fragments for the calculation have been published, but cchs is easier to use and more efficient in terms of time and memory, and can cope with much larger datasets. It also avoids several minor approximations and simplifications.

Edmund Jones

Supplementary materials

Supplementary materials are available in addition to this article. It can be downloaded at

CRAN packages used

cchs, survival, cchs, survival, survey, NestedCohort

CRAN Task Views implied by cited packages

Survival, SocialSciences, ClinicalTrials, Econometrics, OfficialStatistics


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For attribution, please cite this work as

Jones, "The R Journal: cchs: An R Package for Stratified Case-Cohort Studies", The R Journal, 2018

BibTeX citation

  author = {Jones, Edmund},
  title = {The R Journal: cchs: An R Package for Stratified Case-Cohort Studies},
  journal = {The R Journal},
  year = {2018},
  note = {},
  doi = {10.32614/RJ-2018-012},
  volume = {10},
  issue = {1},
  issn = {2073-4859},
  pages = {484-494}