ballast: Stress-Test a Pre-Specified Mixed Model for Repeated Measures

Refits one pre-specified mixed model for repeated measures (MMRM) under families of data and analytic perturbations (covariance structure, degrees-of-freedom method and variance estimator, covariate set, analysis population, alternative analysis data sets, leave-one-out deletions, crossed specification grids, re-randomisation tests, delta-adjusted and reference-based multiple imputation, and alternative estimators) and judges every refit against the pre-specified estimate, confidence interval and p-value. Classifies the result as robust, sensitive or fragile, with a separate flag for marginal significance, and estimates by simulation the probability that a planned design gives a significant and robust result. Fitting uses 'mmrm' (Sabanes Bove et al., 2024, <https://openpharma.github.io/mmrm/>) with 'SAS' 'PROC MIXED' conventions for the least-squares-mean contrast, Kenward-Roger adjustment and the corrected Akaike criterion. Reference-based multiple imputation follows Carpenter, Roger and Kenward (2013) <doi:10.1080/10543406.2013.834911> and was checked against 'rbmi' (Gower-Page, Noci and Wolbers, 2022) <doi:10.21105/joss.04251>.

Version: 0.6.1
Depends: R (≥ 4.1.0)
Imports: mmrm (≥ 0.3.0), stats, utils, parallel
Suggests: ggplot2, emmeans, nlme, MASS, flextable, officer, plotly, htmlwidgets, htmltools, jsonlite, testthat (≥ 3.0.0), knitr, rmarkdown
Published: 2026-10-30
DOI: 10.32614/CRAN.package.ballast (may not be active yet)
Author: Adam Sullivan ORCID iD [aut, cre, cph], Nathan Hogan [ctb] (validation of the SAS reference results), Capricor Therapeutics [fnd]
Maintainer: Adam Sullivan <asullivan at capricor.com>
BugReports: https://github.com/Sullivanstatistics/ballast/issues
License: MIT + file LICENSE
URL: https://github.com/Sullivanstatistics/ballast
NeedsCompilation: no
Language: en-GB
Citation: ballast citation info
Materials: README, NEWS
CRAN checks: ballast results

Documentation:

Reference manual: ballast.html , ballast.pdf
Vignettes: Designing for a robust result (source, R code)
Interpreting the verdict (source, R code)
Missing data: reference-based and delta-adjusted imputation (source, R code)
Quickstart: stress-testing a pre-specified MMRM (source, R code)
For SAS users: reproducing PROC MIXED and PROC MI conventions (source, R code)
Validation summary (source, R code)

Downloads:

Package source: ballast_0.6.1.tar.gz
Windows binaries: r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries: r-release (arm64): not available, r-oldrel (arm64): not available, r-release (x86_64): not available, r-oldrel (x86_64): not available

Linking:

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